YoungPetro - 6/7th Issue - Winter/Spring 2013

WINTER/SPRING / 2013

ISSN 2300-1259

orga

nize

rs

International Student Petroleum Congress & Career Expo

24–26 April 2013AGH U2 Hall · Krakow, PL

Silver Sponsors Student Sponsor PowerBreak Sponsor

Media Patronage

Ministry of Scienceand Higher Education

Ministry of Science and Higher EducationRepublic of Poland




Republic of Poland

AGHUniv.

ofS

ci.

&Te

ch

nology * Drilling, Oil

and

Gas

Faculty*

Support

orga

nize

rs




Media Patronage






Republic of Poland

AGHUniv.

ofS

ci.

&Te

ch


and

Gas

Faculty*

Support

WIN

TER

/SPR

ING

/ 2

013

Call for Papers�YoungPetro is waiting for your paper!

Th e topics of the papers should refer to: Drilling Engineering, Reservoir Engineering, Fuels and Energy, Geology and Geophysics, Environmental Protection, Management and Economics

Papers should be sent to papers @ youngpetro.org

For more information visit youngpetro.org/papers

69

careers.slb.com

Who are we?We are the world’s largest oilfield services company1. Working globally—often in remote and challenging locations—we invent, design, engineer, and apply technology to help our customers find and produce oil and gas safely.

Who are we looking for?We need more than 5,000 graduates to begin dynamic careers in the following domains:

n Engineering, Research and Operations

n Geoscience and Petrotechnical n Commercial and Business

>110,000 employees

>140 nationalities

~ 80 countries of operation

years of

innovation85

1Based on Fortune 500 ranking, 2011.Copyright © 2011 Schlumberger. All rights reserved.

What will you be?

careers.slb.com





>110,000 employees

>140 nationalities


years of

innovation85


What will you be?

careers.slb.com





>110,000 employees

>140 nationalities


years of

innovation85


What will you be?

careers.slb.com





>110,000 employees

>140 nationalities


years of

innovation85


What will you be?

careers.slb.com





>110,000 employees

>140 nationalities


years of

innovation85


What will you be?

WInTer/SPrIng / 2013

winter/spring / 2013

3

These words from Bob Dylan’s classic ballad are perfectly reflecting current trends in en-ergy industry.

We are heading toward cleaner and more effi-cient energy resources, simultaneously excel-ling in fields of HSE and social responsibility. Easy access to natural gas from shales con-tributes to changes in business behavior. For example according to FedEx CEO Frederick W. Smith, the company is likely to shift their truck fleet to natural gas in next decade.

We are also changing - during the last two years YoungPetro evolved from being just-a-crazy idea sitting in heads of a few students to fully functioning magazine inspiring young adepts of petroleum industry from all over the world. For me being able to work on this project was definitely the most valuable and enjoyable experience over my studies. I was given a chance to meet, work and become friends with many brilliant and creative peo-ple thanks to whom the magazine had grown into its current shape. But as all good things my journey with YoungPetro came to an end.

From this place I would like to thank our great editorial board for infinite commitment and thousands of hours of hard work you put into the magazine and all the people who believed in our idea and helped us to do things we thought were impossible. However I am most grateful to you, our readers for being the part of YoungPetro’s community and constant in-spiration for our team.

I truly hope that you will continue your pro-active way of studying and stay inspired to change the industry, I am sure that Michal Turek and Jan Wypijewski – YoungPetro’s new leaders will help you with that. From the next issue of the magazine Michal and Jan will bring you their fresh ideas and lead YoungPetro to new levels of excellence!

Meanwhile in this issue Homer Skokowski will tell you what should be learned from Exx-onValdez spill, Adam Szmiłyk will show you what to do with an old oil rig and Richard Awo and Tudor Precup investigate problems of flow assurance in deepwater and arctic fields. Enjoy!

3 Editor’s Letter 3

The times they are a-changing

4

Editor-in-ChiefWojtek [email protected]

Deputy Editor-in-ChiefPatrycja [email protected]

Art DirectorMarek Nogiecwww.nogiec.org

SalesAnna [email protected]

[email protected] DereńKamil IrnazarovMaciej KędrońKarolina KmakKrzysztof LekkiHomer SkokowskiMichał SolarzAntonia ThurmeierMichał TurekGordon WasilewskiMaciej WawrzkowiczJoanna Wilaszek

MarketingJakub [email protected] [email protected]

LogisticsKacper Ż[email protected] Wypijewski

Science advisorTomasz Wł[email protected]

Social MediaKacper MalinowskiMichał [email protected]

Published by

An O�cial Publication of The Society of Petroleum Engineers Student ChapterP o l a n d • www.spe.net.pl

4


5

One more lesson to be learned from Exxon Valdez oil spillHomer Skokowski

The Godfather of OilMichał Turek, Jan Wypijewski

energy-a Modern Day WeaponHamza Ali

Flow assurance solutions for deepwater and arctic fieldsRichard Awo, Tudor Precup

Platform DecommissioningAdrian Szmiłyk

Natural Gas in RussiaZakharova Victoria

Successful Matrix Stimulation and Wax Cleaning of a High Water Cut Oil Well of East Potwar Region

Mansoor Ahmed Ansari

Initiating the Employee – Employer DialogueIwona Dereń

Let’s Shape the Fuel Market – PetroTrend 2013Jakub Szelkowski, Barbara Pach

7

15

19

23

35

47

52

60

64

5

6

Shell to suspend Arctic drilling in 2013

�Early-march announcement from Shell claims to

pause offshore drilling in the Beaufort and Chuk-

chi Seas following series of accidents. In result two

drillships had been transported for repairs and

would not be able to be fully operational this year.

Ships were damaged in movement, not while drill-

ing. Kulluk’s hull has undergone from heavy storm,

Noble Discoverer suffered from explosion and fire

in port.

“Fracknation” – reaproaching fracking

�Fracking stirs the debate like no other topic,

and there are still many myths about it. 2013 doc-

umentary “Fracknation” makes a major step to find

the truth about it. Film was directed by Phelim

McAleer, Ann McElhinney and Magdalena Segieda

and has been recorded in USA, UK and Poland. The

plot is focused on exposing half-truths and outright

lies propagated by films like “Gasland”: burning

faucets, earthquakes and contaminated water just

to name the few. Directors show lifes of people af-

fected by this propaganda in the most harmful way,

like farmers of Dimock, who deprived of help from

gas industry due to moratorium in Pennsylvania,

suffer poverty, often forced to abandon their farms.

The film is remarkable for several reasons: it has

been funded by Kickstarter, where people from all

around the world were donating small amounts of

money for the project. This reflects a promising

fact, that despite all the mainstream anti-fracking

campaigning, there are lot of people out there who

want more than noisy street protests and Holly-

wood environmentalism.

The second thing “Fracknation” proves is that you

can do an anti-environmentalist film and still don’t

make it “pro-business pamphlet”, to quote The New

York Times.

First successful extraction from gas hydrates

�Japan has successfully extracted natural gas

from frozen methane hydrate deposits under the

sea, in the first example of production of the gas

offshore, officials said on Tuesday. Japaneese sci-

entists used a specialistic technology relayed on

reducing pressure in the underground layers which

hold the methane hydrate 1330 metres below the

sea surface and then they dissolved it into micture

of gas and water. Gas is collected through well

Talisman Energy may withdraw from Poland

�Talisman Energy is changing its policy on Polish

shales. After ExxonMobil it would be the second

player recalculating shale resources unfavourably

for Poland’s economy. Divestment options, includ-

ing in Poland, are being considered. Since 2010

Calgary-based Talisman Energy holds 60% of three

shale concessions in Pomerania. Possible divest-

ment would probably mean Polish entrepreneur

taking Canadian place.

On Stream – Latest NewsGordon Wasilewski


7 7

One More Lesson To Be Learned from Exxon Valdez Oil SpillHomer Skokowski

�It was 24th of March, 1989, when the su-pertanker Exxon Valdez left the port of Valdez bound for Long Beach, California. The captain navigated the ship through Prince William Sound out to the waters of the Gulf of Alaska, the task he had done a hundred times before. Joseph Hazelwood was a proven man, working in Exxon for more than twenty years, ten as an oil tank-er captain. Ten minutes after midnight the vessel was supposed to be sailing nearby Bligh Reef. It was then when the ship ran aground, spilling hundreds of thousands of crude oil barrels, thus changing far more than only the Alaskan shoreline. The trans-formation that occurred in the oil industry, the way it was perceived, regulated and op-erated, was more profound than it initially seemed.

The Day the Hell Broke LooseScores of TV crews and reporters from all around the world were going to Alaska and soon photos of animals covered with oil made the headlines of almost every newspaper. And there were plenty of victims: seals, otters, whales, seabirds and eagles died by hundreds and thousands. The sheer magnitude of the calamity paralyzed the first attempts to coun-teract it. There were many entities with over-lapping authority involved: The Coast Guard, the State of Alaska, the pipeline consortium and Exxon. While Coast Guard was supposed to be ready for oil spills cleanup actions, it lacked equipment. Wherever Exxon wanted

8 One More Lesson To Be Learned from Exxon Valdez Oil Spill

to bring in its own machinery, the permission was denied by the government. There was a particularly bitter battle about the disper-sant, the chemical sprayed from planes over the spill to break up oil into droplets which then can be more easily biodegraded. The lo-cal fishermen were strongly opposed to the use of the dispersant, claiming it will only make things worse. In short, Exxon was por-trayed as the villain of the piece, with every-one trying to push it away from the case, even though the corporation was capable of help-ing.

Can It Be Worse? Yes, It CanWhile the debate about the use of dispersants was going on, forces of nature were preparing to play a little trick in Prince William Sound. 72 hours after the spill a powerful spring

storm went just through the oil-covered wa-ters spreading the spill over the nearby isles, far beyond the initial range. By then it was too late to use dispersant. This would later stand as a ground for accusations that Exxon reacted too slowly or even did not react at all in the first hours after the spill. As if it wasn’t enough to aggravate the situation, captain Hazelwood testified to have been under the influence of alcohol during the grounding. Very soon the ridiculed image of the drunk captain started to serve as an icon of oil indus-try recklessness. Hazelwood’s number-one excuse, according to a David Letterman Top Ten list: “I was just trying to scrape some ice off the reef for my margarita.” In fact, the Ha-zelwood was asleep during the collision with Bligh Reef. The case of the captain intoxica-tion only obscured the real cause, or rather a chain of human errors, that led to catastro-phe. Inadequate corporation safety systems

Homer Skokowski 9


contributed much. There was also overload of work due to severe job cuts aimed at boosting profitability and a broken radar.

Bad ReputationOil industry had bad press since its inception with Standard Oil Company. Exxon Valdez shattered any reputation the business had, leaving everybody, not just Exxon, exposed to the voice of critique of global dimensions. Though, after initial stalemate with govern-ment, Exxon swiftly moved to action and proceeded with oil spill cleanup in a highly professional manner. They spent total sum of $2 billion on cleaning and another $1 billion to settle civil and criminal charges. This gave them advantageous position in court and helped to reduce the severity of fines. It is hard to assess total damage done to the brand considering public relations after the Exxon Valdez case. But that was not the end of the story.

Learning the EnemyExxon Valdez spill posed a great opportunity to study how oil affected wildlife. Media cov-erage, global scale of the event and the fact, that it happened on American waters helped groups of scientists obtain funding for re-search. There was Mandy Lindeberg and her team working for the National Oceanographic and Atmospheric Administration (N.O.A.A.). Her plan was to dig seven thousand holes in the beaches affected by the spill, each fifty centimeters deep, and examine them for oil presence. Jeffrey Short was another scientist, who was granted $500 thousand to establish research salmon hatchery, and investigate how sublethal doses of oil affected fishes. He would expose salmon embryos to the oil, and then examine the mortality rates after two years, when fish returned to its birthplace. This was a way to track more subtle and un-predictable causes of death, due to general

weakness of the organism. Yet another study was carried out by Jim Bodkin and Brenda Bellachey. They analyzed an enzyme called P450, which level is increased in the liver of an animal exposed to oil.

All their work was intently scrutinized by Exx-onMobil scientists, who made every effort to undermine unfavorable outcomes. The com-pany’s position was that all the damage was dealt with. Mandy Lindeberg was followed by Exxon’s cruise ship wherever she went.

Exxon also used the Freedom of Information Act to obtain the raw data as soon as govern-ment paid scientists who had gathered them, to analyze them and to release its own conclu-sion before the scientists did it. The company sent its representatives to conferences where the reports were presented. They would often stand up and aggressively oppose the results. Company’s situation was compared to that of tobacco industry in early sixties, when dan-gers of smoking became widely recognized.

What Exxon Valdez Taught UsIn spite of all the bad reputation, what Exxon did was sound from scientific point of view. Even the most ardent among their opponents confessed that scientists on Exxon’s payroll where “typically ethical and professional”, and their work was appreciated by them. In an interview Jeffrey Short said: “I think in the wider scientific community we’ve won that battle, […] in fact there’s some really elegant work done by people who are not us. So they [ExxonMobil] can have that position if they like, but most people think it’s flawed.”

Mandy Lindeberg could recall one posi-tive aspect of fighting Exxon: knowing that everything she would write or say will be un-der keen eye of the army of scientific consult-ants “forced us to be very good scientists.”

10

Lakeview Gusher1 230 000

Deepwater Horizon550 000

Ixtox 1 Oil Spill470 000

Atlantic Empress/ Aegean Captain

287 000

ABT Summer260 000

Amoco Cadiz225 000

Lakeview Gusher 1910

1978 Amoco Cadiz

Ixtoc 1 Oil Spill 1979

1979 Atlantic Empress/Aegean Captain

Nowruz Oil Spill 1983

1983 Castillo de Bellver

Gulf war oil spill 1991

1991 ABT Summer

Mingbulak Oil Spill 1992

2010 Deepwater Horizon

Year


11

Total spillage 4 289 000

Gulf War Oil Spill270 000 – 820 000

Mingbulak Oil Spill285 000

Nowruz Oil Spill260 000

Castillo de Bellver250 000

= 50 ton

12 One More Lesson To Be Learned from Exxon Valdez Oil Spill

What resulted from the clash of the largest company in the world and an army of inde-pendent researchers was in fact very good sci-ence. Considering all the emotions carried in media reports, both parties managed to stick to the truth. Eventually Exxon had to admit to greater impact of the spill than initially as-sessed. Lot of oil remained in the ground, just half a meter below the surface. Animals suf-fered from oil poisoning many years after the accident. Oil toxicity was proved to be much higher than expected.

And yet there is something more profound to be learned, especially important now, twen-ty-four years after the accident. It’s sound sci-entific dialogue and public recognition of it. This dialogue was present in the Exxon Valdez

case, but fails to be accomplished now in the debate about fracking and shale gas.

There are lot of scientists wanting to contrib-ute, but there is virtually no public dispute about it. There are groups of environmental-ists, who just ignore the science when facing it, and they have huge public support. They don’t want to study the process, or improve the technology to be more safe or environ-mentally friendly, they just want the shale gas initiative to be stopped, once and for all. What Exxon Valdez case proves, is that no matter how controversial topic is, how many influen-tial interest groups may be included or how big money is at stake, there is always space for sound reasoning and dialogue based on facts, not emotions or juggling public opinion.


13

Find us on Facebookfacebook.com/YoungPetro

14

For online version of the magazine and news visit us at youngpetro.org


15 15

The Godfather of OilMichał Turek, Jan Wypijewski

�Everyone knows how the oil and gas indus-try affects our everyday life, but have you ever wondered–while driving your car or sitting in a warm room when the temperature outside is strongly below 0°C–where it all started? Do you know since when hydrocarbons have been indispensable? Nowadays, top oil-pro-ducing countries are Saudi Arabia, Russia and the USA. They produce about one–third world's oil per annum. Therefore your answer about the origin of oil may include one of these countries. If so, you need to be aware that you are wrong. The World's oil and gas in-dustry was born in… Poland in 1853. This year it celebrates its 160th birthday anniversary and it couldn't be in better condition.

It all started by accident and because of one person–the godfather of petroleum industry–Ignacy Lukasiewicz. He was born on 8th March 1822 in Zaduszniki near Mielec (southeastern Poland). The important fact is that Poland at that time was split between three countries: Russia, Prussia and Austria. Ignacy Lukasie-wicz lived in the Austrian part. He was the son of a poor nobleman, the soldier of Ko-

sciuszko Insurrection–Jozef Lukasiewicz and his wife Apolonia. In 1836 he graduated from secondary school in Rzeszow and then due to family financial problems, he started working in chemist's shop in Lancut and in Rzeszow respectively. That work was interrupted by his imprisonment for underground patriotic activity against Austrians in 1846.

He was released from prison after 2 years and then, began working in the chemist's 'Under the golden star' in Lvov. From 1850 to 1852 he was studying pharmacy at universities in Krakow and Vienna. After his studies he re-turned to his previous employer in Lvov.

Memorable surgeryHis adventure with oil, as the legend says, started one day in November. Two Jewish innkeepers entered his apartment with a bucket full of unidentified dense liquid from rocks. They asked if there was a possibility to extract alcohol from the unknown substation. During 1852 and 1853 Ignacy Lukasiewicz and

16

Jan Zeh were researching on crude oil in their chemist's for technical and lightning purpos-es. Finally, they received the kerosene. After that Lukasiewicz with Adam Bratkowski in-vented the first kerosene lamp in the World. Lukasiewicz's kerosene lamp was used for the first time during a surgery at Lvov hospital on 31 July 1853. It is said that the surgery had ended up with a success. After that a doctor was examining the new lamp for some time. He was delighted that it hadn't been smoking. On that day Lukasiewicz made the history. 31 July 1853 is the symbolic date of the begin-ning of not only Polish but also international oil and gas industry. Soon, the whole city of Lvov was using kerosene lamps to illuminate their homes.

Right man at the right timeIn 1854, a man came to Lukasiewicz's phar-macy. He said that he had been buying crude oil from peasants, who had found the spring in the forest near Bobrka. Lukasiewicz decid-ed to visit Bobrka and its landowner Karol

Klobassa. Later that year, they set up the first World's oil mining company in Bobrka, near Krosno. The mine in Bobrka has been opened until now. Lukasiewicz's next step was the opening of the first petroleum refining plant in 1856. The company turned out to be the great success, so he decided to set up several new refining plants.

Technological developmentAt the first, the drilling process was rather unsophisticated. A revolution started in 1862 when the engineer Henryk Walter proposed using hand hammer drilling which made use of Fabian's free-fall drilling system.

After that he initiated the use of new means of blocking the escape of subsoil and under-lying water: lining steel pipes in boreholes, piston pumps with mechanical drives. Thanks to these innovations petroleum extraction begun in the 1860's on a truly industrial scale. By 1862, petroleum had been already flowing from 30 wells operated by 120–150 workers.

17


Money vs...Simultaneously, Ignacy Lukasiewicz was working on the development of his oil dis-tillation technologies. His oil products were awarded at competitions in Jaslo, Lvov and even in Vienna. The legend says that once upon a time in Vienna, he met John D. Rock-efeller. American investor was fascinated by Lukasiewicz's invention, so he proposed co-operation. Lukasiewicz rejected the offer and preferred staying in Poland. He also present-ed the technology of the kerosene lamp and oil distillation to the future billionaire-to-be who, after returning to the USA, set up the 'Standard Oil' company and became the rich-est man ever.

...philanthropyThe truth is that Ignacy Lukasiewicz didn't care about money. Lukasiewicz used to say: 'Gentlemen, I was born in a threadbare cloak, I have worn it all my life, let me die in it!'. He

was known as a big philanthropist in the local community. He established schools, church-es, hospitals and routes. He was a man of creativity, development, social worker and patriot. He died of pneumonia on 7 January 1882 in Chorchowka. In the year of his death, the Karpatians yielded over 20 000 tons of the crude, commonly called oil. To pay tribute to Ignacy Lukasiewicz on the anniversary of the surgery in Lvov–31 July, kerosene lamps bright in every pharmacy.

The motherland of oilThe invention of the kerosene lamp, oil dis-tillation process and the setting-up of world's first oil company by Lukasiewicz made Poland the land, where oil and gas industry were born. It was not in Romania where the first attempts at distillation of petroleum were made in 1897. Not in the USA where modern exploitation of petroleum researches begun in 1860. Not in Russia, whose 'oil history' is six years younger than the business of Polish pharmacist and inventor.

For more information, please visithttp://spe.cup.edu.cn/ OR cupb spe

Future Petroleum Engineer Conference

May 16th

May 17th

May 18th-19th

May 20th

China Universityof Petroleum


19

�Today we are living in such an age where nations are building their nuclear systems, investing their huge budgets in military weapons signing latest technology-based agreements, they are doing right as safety comes first but this time it will not be a con-ventional war (if it happens) between na-tions but rather nations which will destroy opponents using MODERN DAY WEAPON cultural distortion, economic paralysation and capturing and hunting energy resourc-es above all.

Following article provides an insight about energy trends, how global energy mix is go-ing to change, what is future of oil, who is the most thirsty for energy and so many more questions. The knowledge of energy outlook is not just a issue for energy companies, pol-icymakers, engineers etc. It’s an issue involv-ing all of us. We all are connected to this glob-al field in one way or another.

Oil is the world’s dominant fuel (at 33% of current global primary energy consumption). Oil consumption is dominated by transport sector (more than 50% of global consumption and roughly 60% of OECD consumption); oil has lost significant market share in the pow-er and industrial sectors. As with other fuels, demand and supply have been impacted over the years, primarily by the rate and distribu-

tion of global economic growth, but also by technological change (such as the emergence of nuclear power or advances in deepwater exploration, development, and production ca-pability); competition from other fuels (cheap natural gas currently).On the supply side, OPEC holds a heavy majority (77%) of global proved reserves. Oil prices have increased in recent years, averaging about $80 in 2010 and well above $100 so far this year, which would be the highest (nominal) price on record.

Population and income growthPopulation and income growth are the two most powerful driving forces behind the de-mand for energy. The next 20 years are likely to see continued global integration, and rapid growth of low- and medium-income econo-mies. Over the last 20 years world population has increased by 1.6 billion people, and it is projected to rise by 1.4 billion over the next 20 years; the world’s real income has risen by

energy-a Modern Day WeaponHamza Ali

* University of Engineering & Technology

Þ Pakistan

[email protected]

* University Þ Country E-mail

20 Modern Day Weapon

87% over the past 20 years and it is likely to rise by 100% over the next 20 years.

Resource baseAnother key factor is the resource base. Re-search work is based on an assessment of global proved reserves for oil, gas, and coal—those quantities that geological and engineer-ing information indicates with reasonable certainty can be recovered in the future from known reservoirs under existing economic and operating conditions. British Petroleum research data clearly shows that global proved reserves of fossil fuels are sufficient to meet expected consumption growth in the decades to come.

For oil, world proved reserves at the end of 2010 stood at 1.38 trillion barrels—the high-est figure on record. Estimates of oil proved reserves—both in barrel terms and expressed as a reserves/production ratio—have tended to grow over time as new discoveries and im-proved recovery rates have more than offset volumes produced. We conclude that globally, resources are not likely to be a constraint for oil supply availability over the coming dec-ades.

Non-OECD energy consumption is expected to be 68% higher by 2030,and accounts for 93% of global energy growth. OECD energy consumption in 2030 will be just 6% higher than today, with growth averaging 0.3% p.a. to 2030.

Now this statistics clearly shows the hunger of particular section of map and also predict the future trade points. Over the next 20 years, role of natural gas is going to be extremely significant (its development, consumption, prices etc). China and India are expected to be large consumers of fossil fuel in next 20 years and consequently will be responsible for max-imum carbon footprint. Renewables (includ-ing biofuels) account for 18% of the growth in

Others - 10.8%Hydro - 2.2%

Nuclear - 5.8%Gas - 20.9

Coal - 26.8 %Oil - 33.5%

Energy consumption by power source, 2008

Electricity generation - 3%

Residential/ commercial/ agriculture - 10%

Industry - 24%

Transportation - 63%

Percentage shares of oil demand by sector - OECD, 2009

Electricity generation - 7%

Residential/ commercial/ agriculture - 23%

Industry - 18%

Transportation - 52%

Percentage shares of oil demand by sector - global, 2009

Hamza Ali 21


energy to 2030. The rate at which renewables are expected to penetrate the global energy market is similar to the emergence of nuclear power in the 1970s and 1980s.

Keeping in view the changes in fuel mixture and shift of consumption, energy policy de-velopment will gain significance. One of the biggest challenges is to tackle the oil prices and it largely depends on the behaviour of OPEC members. Secondly production rate, continuous supply is/are also required to keep things right. Third policy development should also account the increasing carbon content.

Conclusion�Subject of energy seems to be of great im-portance in the upcoming years as it is one those contents that directly influence our lives and economic strength.

Such reports help us to understand the glob-ally changed behaviour about energy and encourage individuals at national level to take adequate steps to prevent future energy shortfall and in this way try to win this war using MODEN DAY WEAPON.


23

Flow assurance solutions for deepwater and arctic fieldsRichard Awo, Tudor Precup

Abstract�The development of deepwater and low

temperature arctic fields have become a fore front consideration for many energy companies in recent years especially owing to the rising demand of hydrocarbon and declining onshore reserves. These fields pose great development challenges rang-ing from their huge financial involvements, complex facilities front end engineering design, operational complexities and assur-ance of throughput capacity when finally in operation. The later references the fact that multiphased hydrocarbons are typically produced from deepwater fields and trans-ported for long distances to terminals and processing facilities under extremely vary-ing temperature conditions giving rise to chemical reactions which products include; wax, asphaltenes, hydrates, etc which even-tually block flow paths, leading to reduction of up-time and production, large redundan-cy of production systems and increased life-cycle costs. Flow assurance considerations remain a critical aspect to ensuring quicker return on the usual huge investments asso-ciated with deepwater and arctic reservoir developments. Several techniques have been employed around the globe to assure the fully capacity of both tubing strings

and subsea flow lines are fully utilized. This study stems as a review of the operational principles of Electrical Heating Flow Assur-ance Systems with the intension of com-paring system integrity, efficiency and ap-plicability and associated economics.

IntroductionReservoir hydrocarbon fluid, formation water and associated components exist at reser-voir pressure and temperature conditions at a stable equilibrium. When a well is drilled to produce a reservoir changing pressure and temperature results in a disruption of the equilibrium state as the reservoir fluid permeates towards the well and flows into the production system. The fluid naturally attempts to attain a new equilibrium state within the changing environment and the re-sult of this is a phase transition such as gas evolution from the oil, solid precipitation in the hydrocarbon or produced water (Paraffin

* Clausthal University of Technology

Þ Germany

[email protected]

[email protected]


24 Flow assurance solutions for deepwater and arctic fields

and Asphaltenes), condensation of liquid hy-drocarbon from gas and so on. It is generally accepted that any form of solid deposition during the production and processing of oil and gas has unfavorable economic and oper-ational consequences [9]. The phenomenon of phase change which is very typical of deep-water and arctic fields can completely hamper the smooth running of production facilities with its severity increasing with the hydro-static pressure due to water depth and low sea water temperature (40oF).

In order to assure the flow through of the well stream to the process facility, significant in-vestments are made by operators on various flow assurance solutions.

Flow assurance is concerned with under-standing the risk posed by this phenomenon of phase change and developing and applying suiting engineering solution for the subsea flow lines, risers and the topside facilities in order to mitigate the risk. As a background into what phase change can occur in the sub-

sea production system and what flow assur-ance problems can ensue, the mechanisms of deposition of asphaltenes, hydrates and wax are explained in the next section.

Mechanism of Asphaltenes depositionAsphaltenes molecules are complex struc-tured hydrocarbon of relatively high molecu-lar weight with density of about 1.2g/cc. These molecules are soluble in aromatic solvents like Benzene and Toluene but are not soluble in n-alkanes (n-pentane, n-heptane) paraffin-ic solvents. Asphaltenes are polar in nature with the concentration of charges on their surface dependent on the composition of the crude oil. Studies have shown that asphaltene micelles exist in crude oil as colloids which are believed to be stabilized by a protective layer formed by attracting oppositely charged res-ins (a component of the crude oil soluble in Benzene and Toluene at room temperature)

STERIC REPULSION

ATTRACTION

Asphaltene

Resin

�Fig. 1 – Forces acting on Aspaltene Molecules [3]

Richard Awo, Tudor Precup 25


to their surfaces and thus prevent the precip-itation of asphaltenes. Short distance repul-sive intermolecular forces exist between the absorbed resin molecules and the forces keep the asphaltenes from flocculating (see Fig. 1). Any chemical, electrical or mechanical action that deputizes these particles or removes the resin protective layer might lead to floccula-tion and precipitation of apshaltenes.

The Pressure-temperature diagram shown in Fig. 2 presents the asphaltenes precipitation envelope (APE) defining the stability region for asphaltenes in solution. Let the red dot represent a sample reservoir condition. De-pletion of the reservoir causes pressure to decline down to the upper limit of the APE also known as asphaltenes precipitation on-set pressure. At this point the least soluble asphaltenes will precipitate. Continued pres-sure decline causes more asphaltenes to pre-cipitate until the bubble point is reached and gas is evolved from solution. With further decrement in pressure, enough gas will be removed from the system and crude oil may

begin to redissolve asphaltenes at the lower limit of the APE.

During production, asphaltenes can be dest-abilized and can precipitate due to changes in temperature (to a lesser extent), pressure and the chemical composition of the crude [8]. Deposition can occur throughout the production system from the near wellbore region to the distribution facilities. However, whether asphaltenes causes problems or not is dependent on whether it reaches instability during the production of the crude oil to the surface and transportation to the refinery.

Mechanism of Hydrate depositionIn offshore production systems, gas hydrates typically are seen in long flow lines, across gas expansion valves and anywhere in the system where gas and water are present under high pressure and low temperature.

Example reservoir conditionsLiquid

Upper asphaltene envelope

Liquid and asphaltenes

Vapor-liquid equilibrium (bubblepoint)

Liquid and vapor

Lower asphaltene envelope

Increasing temperature

Incre

asing

pres

sure

�Fig. 2 – Asphaltene Precipitation Envelope [6]


Gas hydrates are solid crystalline compound formed when water and gas are combined at low temperature (higher than the freezing point of water) and generally high pressure (e.g. temperatures below 25°C and pressures greater than 1.5 MPa for natural gas hydrates)[11]. Gas hydrates are composed mainly of methane, ethane, propane, CO2 and H2S.

The main frameworks of hydrate crystals are formed with water molecules and appear like ice or wet snow but do not have the solid structure of ice. Enough gas molecules occupy void space in water crystal lattice stabilizing it as shown in Fig. 3.

The hydrate formation envelope below demonstrates a typical behavior of reservoir fluids flowing at surface production facilities. The temperature and pressure conditions for hydrate formation in surface gas processing facilities generally are much lower than those considered in production and reservoir.

Hydrate formation risks are higher in long tie-back lines. Not only that hydrates can plug

and interrupt production, they also consti-tute a safety hazard if not properly handled.

Mechanism of Paraffin Wax depositionParaffin waxes are higher molecular weight components of crude oil that remain dissolved in crude oil under reservoir temperature and pressure conditions and in a state of thermo-dynamic equilibrium. Like Asphaltenes, any disturbance to their equilibrium state may result in the crystallization of paraffin waxes. The effect of temperature on the solubility of parafin components in crude oil and con-densate systems is critical for the mechanism of paraffin wax precipitation. The factor that reduces crude oil temperature contributes to wax crystallization process [5]. Other contrib-uting factor to paraffin wax crystallization is the loss of the volatile (light ends) of crude oil which naturally acts as a solvent, keep-ing the paraffin in solution. Continued drop in temperature causes the light end solvents

Water molecule ‘cage’

Gas molecule (e.g. methane)

No Hydrates

Wellheadconditions

Downstreamconditions

Hydrates

Pres

sure

Temperature

�Fig. 3 – (a) Gas hydrate molecule within water cage, (b) Hydrate Precipitation Envelope [4]



(n-alkanes) in the crude to become less and less soluble until the higher molecular weight components begin to crystallize.

The temperature at which crystallization starts is known as the Wax Appearance Tem-perature (WAT) or Cloud point. Wax melts at 20oF plus above the WAT. A range of thermo-dynamic states of temperature and pressure defines an exclusion called the wax deposition envelope (WDE) within which wax crystalliza-tion is most likely to occur (see Fig. 4).

Further drop in the temperature of a waxy crude oil system below the WAT results in increasing crystallization as well as increased volume of wax. If the system is left undis-turbed, the crystals form a netlike structure which traps oil within it. As this occurrence continues, the oil viscosity and the strength of the netlike structure increases until a cer-

tain temperature called the Pour Point (PP) where the oil ceases to flow is reached. The WAT, PP and flow rate of the crude oil system are important parameters needed for making flow assurance related decisions [5]. The main options for removing deposits include:

Pigging – Cleaning pigs launched into a pipe to mechanically scrape wax from the pipewall and distribute it within the crude in front of the pig.

Wax Inhibitors – There are four main catego-ries of such chemical additives: Crystal mod-ifiers, Pour Point Depressants, Dispersants and Surfactants.

Thermal Techniques – Maintaining or in-creasing the temperature of the oil above the WAT e.g. by increasing the flow rate the wax deposits will either not be laid down or

Wax deposition envelope Hydrodynamic �ow path

Hydrocarbon phase envelope

Reservoir condition

Critical Point

Temperature

Pres

sure

�Fig. 4 – Illustration of Wax Deposit envelope [5]


will be softened and removed. The proposed solutions in this study are concerned with the thermal solution technique.

Flow Assurance SolutionsIn a bid to save the significant cost of oil and gas field development in deep water and in the arctic, many operators have installed subsea production systems with several well streams converging at the manifold chan-neled through a major flowline tied back to a platform with topside processing facilities. These flowlines run several kilometers on the seabed and are exposed to temperatures near 40°F. The inherent heat of the well fluid is lost to the low temperature of the sea bed environ as the fluid flows through the flowline to top-side units.

Also, in the case of a planned maintenance or when unplanned conditions necessitate a shutdown, the hot flow from the reservoir is temporarily stopped. During this period, the cold sea bed environment can create produc-tion problems in subsea flow depending on

the water cut and the flow pressure. Hence flow assurance measures must be taken in due time.

Depending on the section of production sys-tem, various techniques ranging from dead oil circulation to active heating systems are in use today. In practice, one technique alone may not entirely solve the anticipated flow assurance problems. For example, the Electrical Heating System (EHS) will not pre-vent hydrate or wax formation in the subsea trees, manifolds or jumpers as they are not designed to be installed in such systems and the application of the chemical injection tech-niques may be limited by the water cut of the producing well or limited in efficiency. Hence the choice of a flow assurance solution should be made after a close analysis of the expected well fluid temperature, pressure and compo-sition and the entire production system in order to determine the critical flow assurance points on the system.

The essence of any effort to employ a flow as-surance solution is to maintain the well fluid and flow systems outside the pressure, tem-

Piggybackcable

Thermalinsulation

Pipeline

Seabed

Seawater

�Fig. 5 – Direct Electrical Heating System [10]



perature and composition conditions appro-priate for the formation of Hydrates, waxes and precipitation of Asphaltenes. This study is concerned only with the Direct Electrical Heating System and the Electrically Heated Pipe-in-Pipe (PiP) System. Hence, a descrip-tion and comparison of these types of Elec-trical Heating Systems employed today are presented here.

The Principle of Electrical Heating SystemsElectrical Heating System (EHS) provides heat to the flowline by supplying alternating electrical current in the pipe wall. As a result of the electrical resistance of the metal pipe to the current flow, the steel gets warmed up and transfers the heat by thermal conduction to the well fluid. Sufficient heat is provided to warm up the well stream in the flowline as well as compensate for the heat lost to the cold seabed environment.

The excess heat left after that lost to the envi-ronment will determine how fast the system can raise the temperature of the flowline.The principle of heating the pipeline system is well demonstrated by a manipulation of the Ohm’s law and Watt’s Law to show the amount of useful heat generated in a pipe material by passing am alternating current through the pipe.

V=I´R [1]

P=I´V [1]

Where:V – Voltage drop (Volts)I – Electrical Current (Amperes)R – AC Resistance (Ohms)P – Power (Watts)

The Electrical resistance of a material is given by the following equation:

r=×R A

LA C/ [ ]3

Supplycurrent

Current in piggyback cable

Current in seawater

Current transfer zone50 m

Current transfer zone50 m

Anodes

Current in steel pipe

Cablejoints

Electrical‘feeder’ cablesRiser

Pipe/cableconnection

�Fig. 6 – Distribution of Electric Current in DEHS [10]


By rearranging Eq. 3 for and substituting into Eq. 2, the following equation results:

P IL

A= ×

×2 4( ) [ ]r

Eq. 4 indicates the amount of power (useful heated) generated in a conductive material by an electrical current through it.

Two broad categories exist for EHS – the di-rect Electrical Heating System (DEHS) and the Indirect Electrical Heating System (IEHS –Pipe-in-Pipe). While the DEHS is designed such that the electrical current flows along the pipe wall and the electrical resistance gen-erates enough heat to directly warm up the flowline content, the IEHS has an attached heating element to the pipe surface. Via ther-mal conduction, this element transmits a portion of the generated heat to the flowline thereby raising the temperature of the flow-line content above critical temperatures for wax and hydrates precipitation

Direct Electrical Heating SystemThe pipe to be heated here is usually an active conductor. A single core power cable carrying the total current is strapped parallel to the wall of the pipe. Electrical power source from the platform is supplied to the power cable by one or two riser cables connected by the aid of wet mateable connections.

The forward current travels through the cable while the return current is split between the flowline and the sea water. An illustration of the concept is shown in Fig. 5 below.

The concept is a single phase system with open insulation. Hence, the need for addi-tional installation of sacrificial anodes (ap-proximately 50m) at the current transfer zones between the cable and pipe to take care straying AC corrosion causing currents.

Corrosion can also be controlled by maintain-ing the surface current density of the pipe be-low a level at which AC corrosion is induced. Field experience shows that a current density of 240A/m2 has been found to be a safe level [10]. Care must also be taken to avoid cracks in the thermal insulation as leakage of cur-rents may occur as a result of variation in im-pedance along the pipeline.

The efficiency of a DEHS is dependent on the cable, power connections, sea water conduc-tivity and the inner pipe electrical and mag-netic properties.

Design consideration for a DEHS is project and manufacturer specific. However, consid-erations are generally given to the following parameters:

È Material, composition, thermal, electrical and magnetic properties of the pipe.

È Wall thickness, diameter and length. È Pipe insulation – thermal conductivity,

U-value (OHTC) and heat capacity È Thermal properties, flow rate and compo-

sition of the well fluid at different operat-ing modes.

È Surrounding sea bed temperature, elec-trical conductivity of sea water and cur-rent distribution on the pipeline.

The maximum power (current input) is usu-ally determined and designed for the worst case operational scenario, i.e. heating the flowline to melt a wax plug or hydrates with the insulated pipe lying on the sea bed under the lowest seabed temperature. Fig. 6 shows a schematic representation of the distribution of electric current in the DEHS

Pipe-in-Pipe (PIP) Trace Cable Heating SystemPIP is an indirect EHS comprising of active heating copper core trace cables stacked to



the flowline and covered with a high perfor-mance passive insulation materials such as mineral wool, microporous silica, or aerogel. The system uses standard single core electri-cal cables installed in multiples of three along the outer walls of the flowline. At one end of the circuit, one phase of alternating current passes through each of the three cables and at the other end, the three cables are linked to form a kind of star connection such that the sum of the current equals zero. Hence a cable to return the current is not required. Power supply to the cables comes from a dedicated power control unit at the topside which regu-lates electrical power input within the system. The control unit supplies power to the subsea assembly via a subsea umbilical termination assembly and like the DEHS, the umbilical is connected to the PIP system using standard wet-mateable power connectors and flying leads. Due to a combination of the passive insulation and the location of the trace heat-ing against the flowline wall, the linear power input to meet heating needs is relatively low compared to other systems, in turn allowing a lower total power input or heating over great-er distances. See schematic in Fig. 7 below.

Technip has developed and qualified this sys-tem for static flowlines and steel catenary

risers and intends to install the system for a major operator in the North Sea.

However, this study does not include a field case were the system has been installed; rath-er a comparison between DEHS and PIP is presented in the next section.

Comparison of dehs and pip Trace Cable HeatingIt is almost impossible to make a strong com-parison between DEHS and PIP as they both are basically electrical heating systems. How-ever, there are some non trivial distinctions between them as captured below.

Integrity and SafetyThe DEHS has an open insulation system which is exposed to the sea water (see Fig. 5) and if not properly insulated; with the pas-sage of time the insulation integrity will be affected [2]. Additionally, the return electrical current of the system split between the sea water and the pipeline surface if higher than the corrosion inducing current density could

First layerpassive insulation

Centralizer

Carrier pipe

Second layerpassive insulation

Flowline

Fiber-opticcable

�Fig. 7 – Electrically Trace Heated Pipe in Pipe [7]


cause a corrosion of the pipeline especially at the current transfer zones. Also, any earth fault on the cable could generate enough heat which may damage the pipeline violating the integrity of the production system.

At the downstream end of the PIP system is a star connection with a net current equal to zero. By the nature of this design, no current flows into the sea water thereby providing a high level of reliability taking into consider-ation the extended lifetime requirement of such a system.

Monitoring of the temperature profile along the flowline is achieved by the use of optical fiber distributed temperature sensing (DTS).

Efficiency and ApplicabilityThe PIP incorporates a high high-perfor-mance trace heating system and a passive in-sulation thereby providing a very high heat-ing efficiency and a low overall heat transfer co-efficient OHTC (between 0.5W/m2.K and 1.2 W/m2.K). Another attractive advantage is that for wells flowing by the aid of ESP, during a shut down phase the power supply of the pump can be diverted and used for pipeline heating. Another significant bene-fit to the PIP is their low power requirement (30 -100 W/m for warm up and 10 – 30 W/ for temperature maintenance above critical levels) which make them suitable for long tie backs as well as reduces both CAPEX and OPEX for the producer.

As soon as the production system is shut down for any reason, the DEH can be imme-diately activated to preserve the heat of the well fluid. Chemical injections must be used for non- electrically heated sections of the production system such as Subsea trees, man-ifolds and Jumpers. Efficiency of the DEHS is much dependent on the piggy back cable dis-tance to pipe, power frequency and seawater return path. Because it is one-phased, it does

not provide a uniform heating of the flowline stream as heating is more intense on the top-side where the piggy back cable is strapped to the flowline.

Cost and economicsThe configuration of PIP system consists of the flowline, the heating cable, two layers of insulation materials and the outer carrier pipe.

The implication is that the pipes are often of larger diameter than the DEH systems which do not contain an outer pipe (see the insert of Fig. 5) and will definitely attract more pro-curement and installation cost than the DEH system.

The double insulation layers (made of PCM) of the PIP make it an attractive option for increasing flow line cool down time. The PCM material is hydrocarbon based, with a transi-tion temperature of 28o°C. Its energy storage capacity is of 143 MJ/m3. With a 43mm thick PCM layer, the cool down time performance of the PIP is increased by 2.7 days approxi-mately [1] In general terms however, the cost of either system is mostly dependent on the tie back length and the method selected for the installation of the system.

ConclusionFor the next few decades of fossil fuel devel-opment, oil and gas production from deep water fields will continue to stride and flow assurance challenges will also increase.

Whether EHS design to be retrofitted or as part of a new subsea production system it will remain a major flow assurance solution for warming up or keeping flowline content temperature above the critical hydrate and wax formation levels and will continually help to reduce CAPEX/OPEX for operators by



encouraging more tie backs and eliminating the need to construct a cost intensive floating platform.

Besides the EHS, there are also other options like Chemical injection (Thermodynamic and Kinetic inhibitors), hydraflow concept, dead oil circulation, pigging, etc. The task lies in

the hand of the design engineer who must understand the nature of the subsea environ-ment and proffer a lasting solution to flow assurance challenges.

The key to selecting an appropriate system is specific to the project development strategy and expected project deliverables.

References1. Sylvain Denniel, Technip Offshore UK Limited; Jerome Perrin, Genesis France; Antoine Fe-

lix-Henry, Flexi France “Review of Flow Assurance Solutions for Deepwater Field” Paper SPE 16686-MS presented at the Offshore Technology Conference, Houston, Texas, USA, 3–6 May 2004.

2. Rebecca Fisher Roth, INTECSEA, “Direct Electrical Heating of Flowlines–A Guide to Uses and Benefits” Paper SPE 22631-MS presented at the Offshore Technology Conference, Rio de Ja-neiro, Brazil, 4–6 October 2011.

3. Tore A. Garshol “Investigation of Apshaltene precipitation mechansism on the Gyda Field”. Project Work submitted to Department of Engineering and Applied Geophysics, Norwegian University of Science and Technology, December 2005.

4. R. Azarinezhad, A. Chapoy and B. Tohidi “Novel Technique for addressing gas hydrate and flow assurance: Cold flow and Hydraflow”. Centre for gas hydrate research Heriott Watt Uni-versity Edinburgh, Devex Aberdeen, 12–13 May, 2009.

5. Tarek Ahmed. “Equation of state and PVT analysis: Application for improved reservoir mode-ling” Gulf Publishing Company, Houston Texas, Chapter 6, Page 496, 2007.

6. Schlumberger Online. (August 2012) http://www.slb.com/~/media/Files/resources/oilfield_review/ors07/sum07/p22_43.pdf

7. Technip Rigid Pipe Technology online. (September 2012) http://www.technip.com/sites/de-fault/files/technip/publications/attachments/ETH-PIP_WEB.pdf

8. Oilfieldwiki Online (August 2012) http://www.oilfieldwiki.com/wiki/Asphaltenes#cite_note-09. Leontaritis K J, Mansoori G A. Journal of Petroleum Science and Engineering, 1988, 1: 22910. Herald Kulbotten “DEH–Basic Technology” SINTEF Energy research, Gas hydrates operation-

al treatment and futures scenarios Tekna 21–22 October, 2008.11. C. A. Koh, R. E. Westacott, W. Zhang, K. Hirachand, J. L. Creek and A. K. Soper “Mechanism

of gas hydrate formation and inhibition”, Department of Chemistry, King’s College, London, 4 September, 2001.

Student Geophysical Society GEOPHONE

AGH University of Science and Technology

7 - 9 June 2013Cracow, Poland

follow us:

www.shaledays.comwww.facebook.com/StudentShaleDays

www.twitter.com/ShaleDays

[email protected]

at

DAYS

STUDENTSHALE


35

Platform DecommissioningAdrian Szmiłyk

IntroductionThe beginning of "platform life" is the oil rig project. Designing marine rig is a very respon-sible job because each piece of equipment can determine the life of the crew. When the de-sign is finished, the work in construction yard starts. Then the platform is transported to your destination. Rigs are towed as a whole, using tugs or are divided into components, which are transported by barges or ships.

The most important stage of "platform life" is the extraction of the platform, which can take several years. But as everything in the world rigs also have limited lifetime after which there is a need for withdrawing it from use. It is a very complex procedure requiring a balance between factors such as technology, environment, cost, safety, regulations and so-cial responsibility. These factors allow you to decide what happens to the platform–wheth-er it is completely removed, embedded or can be used to create artificial reefs.

Short HistoryThe oil and gas industry had its beginning in 1859. The first offshore well in the Gulf of Mexico (GOM) out of the sight of land was

drilled and completed almost 100 years later–in 1947. This event started new era in oil a and gas industry.

The offshore as well as onshore operators in-stall their facilities and equipment required to produce hydrocarbons. When the hydrocar-bons are no longer economic to produce and facilities and equipment are redundant they are becoming subject of removal and dispos-al. [1] The first documented removal was in GOM. Since 1973 more than 1200 structures have been retired from GOM.

After plans of dump Brent Spar [Fig.1] in deep waters and illegal intervention of envi-ronmental activists the removal of offshore structures from site for disposal on shore for recycling or reuse in other production opera-tions or converted to use other than initially designed for, has been the normal practice. [1]

Nowadays Brent Spar is an icon for the de-commissioning process on a worldwide scale and brought world attention to this process.

* AGH Univ. of Science and Technology

Þ Poland

[email protected]


36 Platform Decommissioning

Thanks to environmental activists in June of 1995 the decision was made not to continue with sea disposal.

Balancing FactorsThe choice of the method to be used for plat-form decommissioning and removal depends on many factors. It is important to strike a balance between the six major factors : tech-nology, environment, cost, safety, regulations and social responsibility (Fig. 4).

Technology

Technology is a big challenge for engineers. Dismanting the platform requires them to

prepare a detailed treatment plan and to find technical solutions. Platforms are very large and heavy structures. Process of rig remov-al is even more difficult because of limited access to the crucial high capacity equipment (lift vessels, towers, etc). There are lots of such lifts in the world, which are scheduled to work almost 24/7, and cost of ownership is high. When you dismantle the structure barges are needed to transport the data ele-ments.

The actual offshore abandonment and remov-al activities are performed in the following sequence: shutdown, well abandonment, de-commissioning, deconstruction, lifting/han-dling, transportation, material disposal, final survey.

�Fig. 1 – The Brent spar, resting in a Norwegian fjord

Adrian Szmiłyk 37


Environment

To remove the platform we need heavy marine equipment, which during opera-tion emits large amounts of CO2 into the atmosphere. Another problem is that not all removed items are suitable for recy-cling so probably will be stored on land. We have a clean seabed, but we must consider whether there is, in some cases, a potential risk of environmental contamination on shore.

Goliat is the first oil field to be developed in the Barents Sea, and thus sets the industry standard as activity migrates ever further north. The Goliat FPSO is built and equipped to meet high standards linked to in-built safe-

ty and a healthy working environment adapt-ed to the climatic conditions in the Barents Sea.

The FPSO will be especially designed for en-vironmentally friendly operations and ener-gy recovery. Electrification from shore will provide reduced emission of CO2 and the oil containment system with segregated ballast tanks and no contact between oil and water preventing the release of polluted ballast wa-ter to the sea.

The oil containment system will also be protected by ballast tanks in the sides and bottom area. The specially designed winter-ization solution will provide good working conditions for the crew.

�Fig. 2 – Partially disassembled platform

38


39

�Fig. 3 – Perenco UK executes the heavy lift removal of the Welland gas production platform in the southern North Sea


Costs

Cost must not to be disregarded just to obtain a desired goal. Society functions as a result of prioritizing expenditures. Regardless of who spends the money, it is society who pays in the end through higher taxes, higher pric-es, less employment opportunities, reduced pensions and reduced dividends. Removal to shore at any cost is not prudent for society in the long term. [1]

The cost of renting a heavy lift vessel (Fig. 3) with a capacity of lifting several tons and barg-es to transport it ranges from a few dozen to a few hundred thousand dollars for one day.

Safety

Removal of platform is a very dangerous process. During this operation, proceed step by step in accordance with the guidelines, because even a small deviation can result in tragedy. Every second during the operation endangers human life and therefore proce-dures must be rigorously adhered to.

Regulations

National and International regulations on the decommissioning of abandoned or disused offshore oil and gas installations have in the past years gone through a metamorphosis. [2] Decommissioning is a global issue and an understanding of the regional and national

regulations in a global issue context, is much more important today than it was in 1995 be-fore the Spar. [1]

The explosion of the Deepwater Horizon drill-ing rig in the Gulf of Mexico on 20 April 2010 and the subsequent massive leak from the oil well on the sea bottom and sinking caused significant environmental, economic and so-cial damage.

The Deepwater Horizon spill exposed a varie-ty of regulatory failures by the federal govern-ment. After the spill, critics attacked regula-tors for an inadequate environmental review process under the National Environmental Policy Act (NEPA).

Policymakers also attacked the Minerals Man-agement Service’s (MMS) numerous conflicts of interest with the oil industry. This Com-ment, however, focuses on the federal gov-ernment’s failure to implement a regulatory regime mandating adequate safety and clean-up technology in deepwater oil exploration.

Ultimately, this Comment seeks to remedy this failure by proposing a regulatory regime that implements a Best Available Technology (BAT) standard for deepwater oil exploration safety and cleanup technology. [6]

GOM as well as North Sea are the most expe-rienced areas in the world in platform decom-missioning.

Decision of platformdecommissioning

Six major factors:- technology

– environment– cost

– safety– regulations

– society

choice of plaform decommission

method

�Fig. 4 – Balancing Factors

Adrian Szmiłyk 41


Social Responsibility

Nowadays the society is a very important el-ement. Citizens want to have more and more influence on the decisions made by politi-cians. Industry must show the people that it’s operations are performed in accordance with all laws and regulations, and are safe for the environment.

If industry will be considering society’s voice, they will gain people trust, and trust is an es-sential element of cooperation.

Options for DecommissioningSteel Jackets are by far the most common type of offshore platform. The majority of jackets are small to medium-size platforms in water depths less than 75 m and weights less than 4000 tones more than half of them are in GOM and North Sea. [3]

Several removal solution for decommission-ing of jackets :

È complete removal È partial removal È toppling È reuse È alternative use

Complete Removal

Complete removal leaves a clean sea bed as found before the platform installation. Ex-ception may be done only with the buried facilities (as foundation piles, conductors, portion of pipelines, etc) and concrete gravity platforms.

This option requires structure to be entirely removed by lifting either in one piece or in sections depending on the size of the jacket and the capacity of the lift vessel. The final survey will locate and remove any piece of

platform or debris still remaining on the sea bottom.

This solution is preferred by governments and other sea users because it solves most prob-lems connected with abandoned platform: safety of navigation, commercial fishing, en-vironmental interests and national security. The complete removal, which is sometimes very expensive, is not favored by the oil in-dustry. [4]

Partial Removal

This solution is allowed for large structures. Any piece of platform equipment must be cut and removed in section by Heavy Lift Vessel and seated in the load spreaders and secured to the deck of the cargo barge. The jacket is cut to the required depth leaving the bottom portion on the sea bed. Pieces of platform may be taken to a deepwater disposal site, transported ashore for recycling or onshore disposal.

Toppling

The toppling of the entire platform involves explosive cutting of selected rig parts in such a way to cause the platform to fall over onto the sea bed. This procedure is finished by leav-ing the required navigational clearance above the toppled platform.

This alternative would be the most economi-cally attractive solution, but it involves prob-lems of engineering to ensure that toppled pieces fall as wanted and that environment, safety and social responsibility issues are con-sidered.[4]

Reuse

The opportunities for reuse of platform at another field site are limited as they are de-signed for specific production requirements, water depth, environmental criteria and soil conditions. The reuse of decommissioned

42


43


platforms gained popularity in the 1980’s with the emergence of small operators and development of smaller, short life fields. GOM facilities in water depths less than about 90 m and less than 15 years old are typically consid-ered for reuse. [3]

Alternative Use

Perhaps the most successful alternative use for a decommissioned platform are artificial reefs. The structure may be toppled in-situ or cut into pieces and placed on the sea bed in a designated area to provide a marine habi-tat. One of the most extensive experiences is using decommissioned platforms as artificial reefs. In Gulf of Mexico more than 140 plat-forms have already been emplaced. [3]

Another way is leaving the rig in place. This option may be attractive for a small number of platforms, which would be extremely dif-ficult to remove (for example enormous con-crete gravity platforms).

Other options for decommissioned platforms include use for eco-tourism sites, aquacul-ture and general tourism activities, research centers and attraction for recreational divers and fishermen.

ConclusionPlatform decommissioning is a very complex process. There should be a balance main-tained between six very important factors, which unfortunately is not easy to achieve.

The oil industry should strive above all to con-solidate the law relating to decommissioning process that among other things would re-quire each operator to establish a special fund for the liquidation of the platform. It is a very difficult task to do but nothing is impossible.

Platform decommissioning is also a big chal-lenge for engineers. The sea conditions to re-move such a large machine are very compli-cated. Therefore, platform designers should note also the final phase of 'life platform" and so certain elements of design to decom-missioning became safer, faster and above all cheaper.

I encourage everyone to pay attention to this issue because it is a relatively young but very powerful, both technologically and deci-sion-making process that is constantly evolv-ing and requires knowledge and experience of many engineers.

References1. William S., Griffin, Managing the Platform Decommissioning Process, SPE International

Conference and Exhibition in China held in Beijing , China, 2–6 November 1998.2. Igiehon M.O., Evolution of International Law on the Decommissioning of oil and Gas Instal-

lations, SPE/EPA/DOE Exploration and Production Environmental Conference held in San Antonio, Texas, 26–28 February 2001.

3. Anthony N.R., Ronalds B.F, Platform Decommissioning Trends, SPE Asia Pacific Oil and Gas Conference and Exhibition held in Brisbane, Australia, 16–18 October 2000.

4. Della Greca A., Offshore Facility Removal: How to Save Cost and Marine Resources, SPE Eu-ropean Petroleum Conference held in Milan, Italy, 22–24 October 1998.

5. Jørgensen K.O., Decommissioning of The Ekofisk I platforms, Offshore Conference held in Houston, Texas, 4–7 May 1998.

6. Bush J., Addressing the Regulatory Collapse Behind the Deepwater Horizon Oil Spill: Imple-menting a “Best Available Technology” Regulatory Regime for Deepwater Oil Exploration Safety and Cleanup Technology, http://law.uoregon.edu.

www.targi.paliwa.pl

May 8-10, 2013

Honourary Patrons

The Warsaw International Expocentre EXPO XXIPrądzyńskiego 12/14, 01-222 Warsaw, Poland

Media Partners

Truckwww.truck-van.pl Van&

Organizer:

. edition20of International „Petrol Station” Fair

Polish Chamber of Liquid Fuels, Slominskiego str. 19, office 521 00-195 Warsaw, Poland; +48 22 637 50 77; e-mail: [email protected]

TECHNOLOGY FUELS ECOLOGY ENERGY CARWASHES


47

Natural Gas in RussiaZakharova Victoria

�Natural gas has been known since ancient times, but its use was not widespread. The first evidence of the use of gas as a fuel, ap-parently, Marco Polo left in his book about traveling to China (XIII c.). In industrial ap-plications the gas was used in 1872 in the U.S.A. In Russia, the use of natural gas as a fuel began only after the October Revolu-tion (1917). During the Second World War in the Saratov and Kuibyshev region natu-ral gas deposits were discovered, the extrac-tion and use of which marked the begin-ning of the Soviet gas industry. The USSR's first pipeline Saratov–Moscow went into operation in 1946.

�After oil having been discovered, for dec-ades gas has been considered its useless by-product and was vented to atmosphere or flared.

But at the present time the natural gas indus-try is experiencing rapid growth thanks to the diverse use of natural gas as a fuel and a feed-stock for the petrochemical industry. Cur-rently, natural gas is a major source of energy.

Russia takes first place in the world in ex-ploration and production of gas. Natural gas production in Russia in 1990 almost did not decrease and remained at the level of 600 bil-lion m3 .

Their main deposits are located in West Si-beria, Volga-Urals, Timan-Pechora and the Northern Caucasus and the Far East. In Rus-sia gas production is intended for domestic consumption and for export to other coun-tries. About 30-50% of the extracted natural gas is intended for export, which will regular-ly replenish the budget of the country.

Russia is the largest exporter of natural gas. It is the only supplier of gas to Estonia, Lat-via, Lithuania and Slovakia, it provides 80% of the gas needed in Hungary and Poland, more than 70%–in the Czech Republic, 65%–in Turkey, 42%–in Ukraine, and 40% and 25% in Germany and France respectively.

An increasing number of the reservoirs is located offshore, in poorly accessible areas, often far away from the major consumption sites.

The industry faces therefore great technical and economical problems of transporting natural gas to the consumers.

* Gubkin Russian State Univ. of Oil and Gas

Þ Russia

[email protected]


48 Natural Gas in Russia

The three types of natural gas are generally distinguished:

1. nonassociated gas which is not in contact with oil

2. gas cap–associated gas overlying the oil phase in the reservoir

3. associated gas "dissolved" in the oil in the reservoir (dissolved gas)

However, there is more than the type of nat-ural gas and the properties of oil with which it may be associated – what is the most im-portant factor is the chemical composition of the gas. It affects the processing that the gas will have to undergo to meet the speci-fications of its transportation by pipeline or in the form of LNG (liquefied natural gas). Natural gas from different deposits varies. The knowledge of the composition and the properties of natural gas is essential at all stages of production, processing, transporta-tion and storage.

The characteristic features of natural gas:

1. It is difficult to form compounds with other elements or substances

2. The gas atoms are not connected to the molecule, these molecules are monatomic

3. Natural gas atoms are characterized by high values of the ionization energy and, as a rule, a negative value energy facili-ties to electron

Generally, the higher the molecular weight of the hydrocarbon, the less of it is contained in natural gas.

Natural gas is transported by pipelines as compressed gas or liquefied gas. Gas at the pressure of 75 atmospheres flows through the pipes. Over the gas pipeline it loses energy, overcoming the force of friction between the gas and the tube wall, and between the lay-ers of gas. Therefore, after a certain period it is necessary to build compressor stations at which the gas is squeezed up to 75 atm.

Others Korea U.S.A.

Germany Italy Japan

OthersAlgeriaCanada

NorwayQatarRussia

Natural Gas Net Exporters

Others IranQatar

CanadaUSARussia

Natural Gas Producers

Natural Gas Net Importers

�Fig. 3 – Key world energy statistics 2012

Zakharova Victoria 49


Natural gas produced in Russia is delivered into gas pipelines, integrated in the Unified Gas Supply System (UGSS) of Russia. UGSS is the world's largest gas transmission system and represents a unique technological sys-tem that includes gas extraction, processing, transportation, storage and distribution fa-cilities. UGSS provides a continuous cycle of gas from the wellhead to the end user. Unified Gas Supply System of Russia belongs to "Gaz-prom".

South Stream is a new project by Russia-Ita-ly-France-Germany, aimed at strengthening the European energy security. All the pipeline will be enough to go around the Earth 4 times

Natural gas storage is necessary for the sea-sonal regulation of consumption and gas sup-ply, as demand for heating, for instance, is dif-ferent in winter and in summer. Gas storage is a geological structure or artificial reservoir used for gas storage. Work of storage is char-acterized by two main parameters–volume and power. The former describes the storage capacity–the active and buffer gas volumes, the latter shows the daily performance of se-

lection and gas injection, the period of stor-age at maximum capacity.

Two main storage methods are employed:

È cryogenic storage in gas-holder, as LNG È underground storage in depleted reser-

voirs and salt cavities.

There are more than 600 underground gas storage in the world

Underground storage in salt caverns is used primarily to cover peak loads, because they can be operated in the "jerk" mode with the

�Fig. 5 – Underground storage

�Fig. 4 – Cryogenic storage

50 Natural Gas in Russia

performance of selection; the order of se-lection of the gas storage capacity in porous structures, and the number of cycles can be up to 20 a year. For these reasons, the crea-tion of the gas storage in salt has received much attention in the developed world. It is also associated with market conditions and the functioning of the gas, as the gas storage in salt can be used to compensate for short-term fluctuations in gas consumption, to pre-vent penalties for imbalance in the supply of gas due to gas pipeline accidents, as well as procurement planning at the regional level, according to the monthly or daily fluctuations in gas prices.

The situation of Russian gas industry is unique–in fact, all public functions are del-egated to one of the economic entities–Gaz-prom, the activity of the state is limited to the

regulation of gas prices in the country. Gaz-prom controls 60% of gas reserves in Russia. It accounts for 84% of Russian gas produc-tion, and nearly 100% of transportation

At the present stage of the natural gas indus-try one of the most important elements of the economy of the Russian Federation is the reliable operation on which its further eco-nomic development depends.

In the coming decades, natural gas will con-tinue to strengthen its position in world en-ergy. According to the International Energy Agency, the share of gas is now 22% and will continue to grow due to the continuing in-crease in demand. Over the past ten years, the demand for gas has shown the average annual growth of 2.5%. By 2030, its consumption is expected to double.

References1. Architektura Russia – http://apxu.ru, Web 2012.2. Gazprom Company – http://gazprom.ru, Web 2013.3. International Energy Agency – http://iea.org, Web 2013.4. Russian Modern Library – http://modernlib.ru, Web 2013.5. Young Scientist - Monthly Scientific Journal – http://moluch.ru, Web 2012.6. Russian National Political Encyclopedia – http://politike.ru, Web 2012.7. Technical Journal of Ukraine – http://tehnichka.com, Web 2013.8. The probing - Analytical Search Portal – http://zondir.ru, Web 2013.

Field name Field type Opening Year Gas Reserve (m3)

Zapolyarnoye condensate gas and oil 1965 0.7 trillion

Sakhalin-3 oil and gas 1992 1.4 trillion

Rusanovskoye condensate gas 1992 3.0 trillion

Leningradskoye gas 1992 3.0 trillion

Stockman condensate gas 1988 3.7 trillion

Bovanenko condensate gas and oil 1971 5.9 trillion

Yamburg condensate gas and oil 1969 8.2 trillion

Urengoy gas 1966 10 trillion

�Table 1 – The most important gas fields in Russia

52

Successful Matrix Stimulation and Wax Cleaning of a High Water Cut Oil Well of East Potwar Region: A Case StudyMansoor Ahmed Ansari

Abstract�Effective acid diversion across high per-

meable and fractured carbonate reservoirs have always been challenging and even more complicated when stimulating high water cut wells. In these type of wells, the challenge is to stimulate the oil-bearing zones rather than the water-bearing zone. To achieve the diversion, polymer-based di-verters were had been used earlier which re-sulted in lower efficiency. In the case study discussed in this paper, a polymer-free di-verter (Non-Damaging and Diverting Acid System) was used to divert and effectively stimulate the target formation.

The target formation has been produced at high water cut which was highly sensitive to the pressure drawdown applied at the formation face. The prime objective of the treatment was to reduce the formation-face drawdown by treating near wellbore dam-age, so that the reduction in water cut and the increase in oil rate could be achieved. The acid treatment of 15%HCl with polymer-free diverter system was used for efficient and well controlled matrix stimulation. The sys-tem consisted of a self-diverter which forms a gel as acid spent, and temporarily blocks the pore throat allowing efficient diversion of the

main acid to the oil bearing zones. When it comes in contact with hydrocarbons, it starts breaking, leaving the pore throat clean. Wax/Asphaltene clean out program is also carried out with organic solvents inside wellbore and production tubing.

Well tests were performed before and after the stimulation treatment. The results of the tests indicated an increase of ≈130 bbl/day in oil production with decrease of water cut to zero. The increase in oil production and elim-ination of water cut shows the success of the stimulation treatment.

Introduction�Matrix acid stimulation has been used for decades as an excellent technique to improve production of oil and gas wells. It improves the production by decreasing skin, bypassing the damage zone or creating worm holes in carbonate formation. Every stimulation job requires deep concentration for its designing which will lead to success. Over the years,

* NED Univ. of Engineering & Technology

Þ Pakistan

[email protected]


Mansoor Ahmed Ansari 53


stimulation jobs have been designed to tar-get oil zones and damaged zones. In an active water drive oil reservoir, the major concern is to prevent the water zone from stimulating fluid. With water cut fields, successful stim-ulation treatment involves reviewing the well history, reservoir characteristics, and poten-tial production results before selecting the optimum stimulation treatment [1]. Howev-er, there is always a risk of stimulating the water zone.

The target formation is a highly fractured carbonate reservoir having high secondary permeability. Permeability of the reservoir varies from 330md to 870md. Due to high permeability, uniform stimulation with the use of conventional stimulation techniques is difficult. Effective diversion is the key for the success of stimulation treatment to achieve uniform treatment. Without diversion, acid seeks the path of least resistance and moves only in a small portion of the whole interval. Chemical diverting agents

temporarily block the undamaged or high permeable interval and divert the acid to-

wards the damage or low permeable interval. Due to high permeability and damaged zones, diversion is highly recommended in these res-ervoirs.

Conventional stimulation treatments use reg-ular acid or retarded acids [2, 3] in conjunc-tion with chemical diverters including foams [4] to fully stimulate long, non-uniform car-bonate formation. The most commonly used chemical diverters are polymer-based [5], and they are associated with induced formation damage [6]. To perform the stimulation of entire zone uniformly a polymer-free divert-er system has been developed. The system is supplied as an active solution. Upon ad-dition to an aqueous brine solution or upon acid spending into the formation, the Gelling Agent will generate an elastic gel. The gel will break upon contact with isopropanol or other hydrocarbon fluids leaving back a clean for-mation matrix with almost no impairment to original matrix permeability and eliminates the concern of ineffective stimulation.

Stimulation by coiled tubing was shown to be the best tool for acid placement and to

�Fig. 1 – Polymer free divert system viscosity for spent system

0 5 10 15 200

50

100

150

200

250

HCl % (volume) spent

Visc

osity

(cP)

54 Successful Matrix Stimulation and Wax Cleaning of a High Water Cut Oil Well

get maximum coverage [7, 8]. Because of the non-damaging and effectiveness as diverting agent polymer free diverter system is selected for stimulating the well in the targeted for-mation of the field.

As targeted formation contains high wax con-tent due to which VLP of the well is deceased, therefore to improve it, a wax cleaning pro-gram with toluene and diesel in the ratio of 70:30 is also carried out.

The Field�The target formation is a fractured lime-stone formation, which has secondary poros-ity. It encloses considerable amount of oil but as we produce it, water encroachment occurs as reservoir is supported by an active edge water drive. It has a net pay thickness of 90m. It produces crude oil, which has 33°–35° API Gravity. The GOR at the separator is about 1931 scf/STB. So the extracted crude oil can also be known as Black Oil.

The well was completed in 2005. Continued production from the well resultes in water

conning due to excessive drawdown which may be due to skin and wax deposits. The treatment is designed to improve well deliv-erability to minimize drawdown and water coning and also to clean up the wax deposits in the tubing to improve VLP and prevent choke plugging.

The Carbonate Challenge�Carbonate matrix stimulation has been ex-tensively researched and discussed in numer-ous publications [9, 10].

With the selection of right stimulation fluid and injection rate, one more important con-sideration is the diversion of the stimulation fluid across the reservoir, not only the high permeable layers or less damage interval. In general, two ways of diversion are available namely mechanical diversion and chemical diversion.

Mechanical diversion

Tools are run inside the well bore which pro-vides mechanical diversion to the stimulating

100

150

200

250

0

10

20

30

40

50

Water cut (%)

Oil rate (bbl/day)

Dec 2, 12Jun 2, 12Dec 3, 11Jun 3, 11Dec 3, 10Jun 3, 10

Time

Wat

er c

ut (%

)

Oil

rate

(bbl

/day

)

�Fig. 2 – Well Production History



fluid. Typically used mechanical diverters are Packers and bridge plugs, ball sealers or jet-ting devices.

Packers and bridge plug has been used with success in through tubing operations. Packers and plugs are set between the targeted in-tervals which provide mechanical separation between two intervals. But they require extra time and cost for placing and removal.

Balls sealers shut off individual perforations from taking fluid. When we pump the balls, these will set in the perforations at a min-imum differential pressure. Usually a large number of balls is needed to be pumped which is burdensome activity. It cannot be used in open hole completion.

Jetting devices are popular for use with coil tubing devices and direct the flow towards the concentrated streams. The impact force and direction of nozzle is used to place the acid at desired location. Due to diameter restriction we can not use it.

Chemical Diversion

Fluid viscosity and solid particles are used to create the resistance in the flow of acid in un-desired interval.

Particulate or thin film-forming agents were widely used in the early stage of matrix stimu-lation. Particles such as Benzoic acid, rock salt or oil soluble resins are used to form a tem-porary layer which diverts the acid towards damage interval. This occurs independently of fluid in the formation [11].

The other group of chemical diverters consists of viscous fluids. As it enters the formation due to its viscosity it diverts the acid towards damage interval.

Viscous diverters consist of three main groups, namely polymer-based fluids, foamed fluids and non-polymer fluids.

Polymer diversion is based on the differential pressure created between a zone that accepts the polymer and a zone that does not accept the polymer. Some polymers are nonreactive. Others are self-diverting–it increases its vis-cosity at particular pH and decreases its vis-cosity when the acid is spent. The problem is the small pH window for the treatment.

Foamed fluid consists of liquid and gase-ous phases which form required differential pressure in the formation. Several authors have shown cases where properly engineered foams remained stable in water-rich environ-ment, while emulsion was separated in phas-es in oil-saturated layers [12, 13]. The draw-back with foamed diverter is that it requires nitrogen tanks and extra pumping unit.

Polymer-free diverter system shows simi-lar properties. The major advantage of this system over conventional acids is that it is non-polymeric and non-damaging. Unlike other diverting materials, such as foam and particulates, this system can be pumped as a single fluid, which will stimulate and divert in one step. Alternatively, it can be pumped in several stages with regular or retarded acid stages. Also, this fluid can be used for the stimulation of wells with a BHST of up to 400 0F. [14]

The normal additives like corrosion inhibitor, chelating agent and iron control agent are compatible with this system. When stimu-lating carbonate reservoir HCl reacts with CaCO3 and creates worm holes

CaCO3 + HCl ® CaCl2 + CO2 + H2O [1]

Calcium chloride is produced while the acid is spent. Upon acid spending into the forma-tion, the gelling agent will generate an elastic gel. This elastic gel increases the viscosity (see Fig. 1). The resulting high viscosity creates temporary blocking of the pores and divert-ing the acid towards un-stimulated interval. The gel will break upon contact with isopro-


panol or other hydrocarbon fluids leaving back a clean formation matrix with almost no impairment to original matrix permeability. Post flush of a mutual solvent will also help in break and flow back of treatment fluid.

Since this system does not viscosify in the tubing string, it can be easily pumped through coiled tubing in both cased and open-hole completions. Polymer-free diverter sys-tem contains no solids that could bridge when pumped through coiled tubing. With CT, this system provides the best results when di-verting in carbonate reservoirs. It can also be used for stimulating horizontal wells. Unlike other diverting materials, such as foam and particulate, polymer free diverter system can be pumped as a single fluid stage, which will stimulate and divert in one step. It can also be pumped in several stages alter-nately with regular or retarded acids. This self diverting acid combines the capabilities of stimulation and diversion in one process,

which significantly reduces the operation complexity.

Case Study of The Well�The well was drilled down to a depth of 2274m in the targeted Formation. Although the primary objectives were other forma-tions, the well was completed as a dual string producer from the Formation, in 2005, due to its encouraging test results. The formation is known to be an oil bearing carbonate and has generally demonstrated significant pres-sure support due to the presence of a strong aquifer. The well is an open hole completion having reservoir pressure of 4440 Pisa and BHT of 185°F.

Pressure transient testing was carried out in a DST at the inception of the well. Though the entire data set could not be matched using a single set of variables, the general consensus

Pre-Treatment Testing Post-Treatment Testing Repeat Testing

0 50 100 150 200 250 300 350 400 450 5000

500

1000

1500

2000

2500

3000

Oil rate (bbl/day)

130 bbl/day increment

FWH

P (p

sia)

�Fig. 2 – Well Production History



was that the reservoir permeability was high, with a moderate skin.

Continued production from the Reservoir had resulted in the encroachment and break-through of water from the aquifer. The sen-sitivity of water cut to drawdown was clear indication of water coning. To keep the well producing water free, initially the well was gradually choked back. The issue was further compounded by the deposition of organic ma-terials in the long string, resulting in restric-tions and choke plugging problems. Latest test results prior to the remedial job carried out on the well are presented in the table 1.

As the results clearly indicate, the well was suffering from water coning issues. To ascer-tain continued water free production from the reservoir to maximize oil recoveries, it be-came necessary to address the diagnosed skin to effectively achieve higher production rates at a reduced drawdown.

Well bore clean out Treatment was started with the wax clean out job. 100bbl of Toluene + Diesel were mixed for the wellbore cleanout operations. The Toluene – Diesel mixture was pumped in batches of 3 bbl, each batch circu-lated out by 15 bbls of NH4Cl. During the tub-ing cleanout operations, the well was being continuously flowed at moderate rates into the flare pit to allow for effective displace-ments of solids out of the wellbore. Total vol-ume of Toluene-Diesel mixture used during the operations amounted to 100 bbl while 443 bbls of 4% NH4Cl brine were used in effective-ly cleaning well tubing.

Acidization treatment was designed to pump the acid at different depths of open hole but unfortunately during RIH, coil tubing experi-ence slack at 2714m so it is decided to limit maximum injection depth up to 2713m.Treat-ment started with the pumping of Mutual solvent based on 4% NH4Cl is used as pre-flush. The main acid treatment was pumped in stages comprising of live acid and diverter,

of 38bbl and 12bbl respectively. The sequence and volume of injection of each stage is pre-sented below.

Pre-Flush 4% NH4Cl Brine 71 bbl

Main Treatment15% HCl 190 bbl

NDA-S Diverter 48 bbl

Post-Flush 4% NH4Cl Brine 48 bbl

Nitrogen lift off was not required due to high reservoir pressure and well started to off load.

Both strings have been effectively cleaned. Well test is performed using test separator and results shows an increase of 130bbl/day in oil production (see fig.3) while reduc-ing drawdown has eliminated the water cut. Well tests are performed two times with a gap of two weeks which shows that water free production from the well is sustained (Table 2).

Conclusions�The treatment objectives of this well in-clude cleaning of wax in the tubing and stim-ulation of near well bore damage. To achieve these goals, an approach was developed, for wax cleaning toluene and diesel mixture is used while in stimulation acid and a self di-verter is used, both with combination of coil tubing.

Because pre and post-stimulation PLT logs were unavailable due to commercial and eco-nomic constraints, it is impossible to con-clude where the actual stimulation fluid went. The success of the stimulation treatment is entirely based on pre and post well test re-sults and production data.

The following conclusions were reached re-garding the treatment performance:

The polymer free diverter system provides effective diversion and allowed acid to stim-


ulate damaged interval and help in effective stimulation.

After treatment, an increase of 130bbl/day in oil production is observed while water cut re-duces to 0% (see fig 2, 3).

Wax clean out is done effectively with toluene and diesel mixture.

Acknowledgments�The author would like to thank Pakistan Petroleum Limited for the permission to

publish this paper. The author also would like to thanks to Dr Fareed Siddiqui, Mr Noman Khan and Mr Sheharyar Mansur for data and support while completing this case study.

NomenclaturesVLP Vertical Lift PerformanceGOR Gas Oil RatioScf/STB Cubic feet per Stock Tank BarrelBHT Bottom Hole TemperatureCT Coil TubingRIH Run In HolePLT Production Logging Toolbbl/day barrels per dayDST Drill Stem Test

References1. Chang, F., Qu, Q. and Freniner W.: “A Noval Self-Diverting-Acid Developed for Matrix Stim-

ulation of Carbonate Reservoirs” paper SPE 65033, presented at the 2001 SPE International Symposium on Oil Field Chemistry held in Houston, Texas, 13–16 February 2001.

2. Navarrete, R.C., Holms, B.A., McConnell, Linton, D.E.: “Emulsified Acid Enhances Well Pro-duction in High-Temperature Carbonate Formations,” paper SPE 50612 presented at the 1998 SPE European Petroleum Conference held in The Hague, The Netherlands, October 20–22.

3. Nasr-El-Din,H.A. Solares, J.R., Al-Mutairi, S.H. Mahoney, M.D.: “Field Application of Emulsi-fied Acid- Based System to Stimulate Deep, Sour Gas Reservoirs in Saudi Arabia,” paper SPE 71693 presented at the 2001 SPE Annual Conference and Exhibition held in New Orleans, LA, 30 September to 03 October.

4. Logan, E.D., Bjomen, K.H., and Sarver, D.R.: “Foamed Diversion in the Chase Series of Hugot-on Field in the Mid-Continent,” paper SPE 37432 presented at the 1997 SPE Production Oper-ations Symposium held in Oklahoma City, OK, March 9–11.

5. Lynn, J.D. and Nasr-El-Din, H.A.: “A core Based Comparison of the Reaction Characteristics of Emulsified and in-situ Gelled Acids in Low Permeability, High Temperature, Gas Bearing Carbonates,” paper SPE 65386 presented at the 2001 SPE International Symposium on Oil-field Chemistry held in Houston, TX, February 13–16.

6. Nasr-El-Din, H.A., Taylor, K.C. and Al-Hajji, H.H.: “Propagation of Crosslinkers Used in In-Si-tu Gelled Acids in Carbonate Reservoirs,” paper SPE 75257 presented at the 2002 SPE Sympo-sium on Improved Oil Recovery held in Tulsa, OK, April 13–17.

7. Safwat, M., Nasr-El-Din, H.A. Dossary, K.A., McClelland, K., Samuel, M., “Enhancement of Stimulation Treatment of Water Injection Wells Using a New Polymer-Free Diversion Sys-tem,” paper SPE 78588 presented at the 2002 SPE International Symposium on Formation Damage Control, Abu Dhabi, UAE, 13–16 October 2002.

8. Saxon, A., Chariag, B., and Reda Abdel Rahman, M.: “An Effective Matrix Diversion Tech-nique for Carbonate Formations,” paper SPE 37734 presented at the 1997 Middle East Oil Show, Bahrain, March 15- 18.

9. Robert J.A. and Crowe C.W.: “Carbonate Acidizing Design”, Reservoir stimulation Vol.3



10. Daccord, G., Touboul, E. and Lenormand, R.: “Carbonate Acidizing Towards a Quantitative Model of the Wormholing Phenomenon,” paper SPE 16887, SPE Production Engineering (Feb-ruary 1989)

11. Shnaib,F. , Desouky, A.M., Mehrotra, N., Kuthubdeen, M., Rutzinger, G., Judd, T.C., and Re-bello, R.P.: “Case Study of Successful Matrix Stimulation of High-Water-Cut Wells in Dubai Offshore Fields,” paper IPTC 13203 presented at International Petroleum Technology Confer-ence, Doha, Qatar , 7–9 December 2009.

12. Zerhboub, M., Touboul, E., Ben-Naceur, K, and Thomas, R.L.: “Matrix Acidizing: A Noval Ap-proach to Foam Diversion,” paper SPE 22854 presented at the 66th Annual Technical Confer-ence and Exhibition held in Dallas TX, 6–9 October 1991.

13. Parlar M., Parris M.D, Jasiniki R.J, Robert J.A.: “An Experimental Study of Foam Flow Through Berea Sandstone with Applications of Foam Diversion in Matrix Acidizing”, paper SPE 29678 presented at the Western Regional meeting held in Bakersfield CA, 8–10 March 1995.

14. Al-Mutawa, M., Al-Anzi, Ravula, C., Al Jalahmah, Jemmali, M., Samuel, E., and Samuel, M.: “Field Cases of a Zero Damaging Stimulation and Diversion Fluid from the Carbonate Forma-tions in North Kuwait,” paper SPE 80225 presented at the SPE International Symposium on Oilfield Chemistry held in Houston, Texas, U.S.A., 5–8 February 2003.

60

Initiating the Employee – Employer Dialogue15th Engineering Job Fair in Cracow

Iwona Dereń

�The voices of visitors have died away and the expositions have become empty. It means, that The 15th Jubilee Engineering Fair is over! Similarly to previous years, the exposition astonished arrivals by its remarkable invention and afforded them a pleasant background for meetings.

If to look around and see how many people took part in this event, it’s clear, that there is definitely a need and desire to make the link between the academic world and companies.

This is a great start!

Before it began�The idea of Engineering Job Fairs was con-ceived in 1997 and 1998, owing to the will to create and occasion for students and young professionals to meet with employers in an informal setting, discover exciting oppor-

tunities available in the start-up field, learn more about job, and internship opportunities offered by companies, government agencies, and non-profit organizations where students and young professionals might like to work. Career fairs give businesses and organizations a chance to present their values to prospec-tive employees and community members.

The amount of the companies during the first edition in 1999 reached 30 and approxi-mately 500 visitors. This was a good forecast for the future of engineers and people who were looking for a job. This high level turnout clearly indicated that companies need work-ers from Poland.

Since that time, Engineering Job Fairs organ-ized by BEST AGH Krakow Students Associ-ation take place at the beginning of the year – in March – at Sport Hall of Wisła Kraków, located next to dormitories and buildings of AGH University.

60

Iwona Dereń 61


Every year and every edition brings more companies, more visitors and more challeng-es.

Initiating the Dialogue�On March 7th 2012, the city of Krakow at Sport Hall of Wisła Kraków, organized by BEST AGH Krakow Students Association, the 15th Engineering Job Fair hosted representa-tives of the companies, students, graduates and young professionals. Aside from science and technology-oriented companies, a num-ber of management-oriented companies par-ticipated in the career fair. This exhibition event appeared to be a great success – it has at-tracted a great deal of interest from students and employers alike. Part of the purpose of the career fair was to expose graduating stu-dents to potential employers. Many of them took park in the programme of conferences, seminars and workshops. Also, they could gain more information about companies like: ABB, Cisco, EPO, Ericpol, FMC Technologies, Oracle, Valeo Autosystemy and more that fea-tured during this event. The company Schib-sted Tech Polska founded a tablet, that was a reward in one of the prize-draws. According to the voting – ABB company was chosen as the best exhibitor of the 15th Engineering Job Fairs.

Expanding Your Horizons�Whether you're a student looking for an internship, a young professional looking for your first job or a seasoned engineer looking to breathe new life into your career, there are a lot of ways to go about looking for that dream internship, but few are as effec-tive and time-worthy as a career fairs, which are a gold-mine of networking opportuni-ties, getting profession advice or practicing job-searching skills.

Being unprepared is a recipe for failure, and failure is for tools.

Sadly, it is well known that far too many stu-dents attend career fairs completely mind-lessly. Dressed like they just rolled out of bed, not prepared at all, without defined career goals and lacking any enthusiasm or self-con-fidence – this is the common image of some students attending job fairs.

The first step to avoid this is preparing, which should be obviously done before the job fair starts. The resume is a snapshot of your entire professional life. At a career fair you’ll look like a newbie without it.

However, it’s not enough to just have a re-sume. It needs to be tailored to perfection.

Your superficies, outer appearance is part of the impression you make on people, and it is taken as a reflection of your in-

ner value, worthiness and qualities.

Everybody knows, that are a limited amount of internships, and a seemingly never-end-ing torrent of desperate students willing to sing, dance, jump, and do anything else to get them.

62 Initiating the Employee – Employer Dialogue

YoungPetro at the Engineering Job Fair�Our YoungPetro Magazine was honored to have a stand during the Job Fair! It was a pleasure for us to get to know that so many people are interested in what we do. We would like to thank you all for taking the time to visit our stand during this event! We en-joyed meeting you and were glad that you had the chance to learn more about our magazine and we hope that you have also found our conversations informative and useful.

As the editorial board of YoungPetro, we would like to thank you all for taking the time to visit our stand during this event!

We enjoyed meeting you and were glad that you had the chance to learn more about our magazine and we hope that you have also

found our conversations informative and useful.

To Be Continued…�The 15th Engineering Job Fair is over but that doesn't mean the work is finished. The days and weeks in the wake of a career fair are the most opportune time to improve your chances of being called back for an interview.

Overall, the International 15th Engineering Job Fair once again confirmed its position as the important event of this kind in Kraków.So, regardless of the extent to which technol-ogy makes it easier and faster to share infor-mation between job seekers and employers, nothing replaces in-person contact for mak-ing an impression.

Hopefully, next year’s edition will bring even bigger successes!

The exchange of experiences with business professionals• Proven business development concepts• Ready-made solutions for current problems• Innovative sources of additional income• Ways to look for savings• Market trends and prognosis

Building and strengthening successful business relationships • Direct contact with the most important

decision-making business world representatives• The opportunity to present your current

offer in person• Creating and strengthening your image

among the market leaders

Media partners: Contact the organizer:BROG Marketing, tel. 22 594 45 83e-mail: [email protected]

www.petrotrend.pl

The mosT imporTanT conference for professionals in The fuel polish secTor

64

Let’s Shape the Fuel Market – PetroTrend 2013!Jakub Szelkowski, Barbara Pach

�The constructive discussions, an exhibi-tion and promotion of the most important companies of the fuel sector, priceless ex-perience – that exactly was PetroTrend Fuel Forum 2013! These event has got a prestig-ious position among the conferences held in the Polish fuel sector for many years! The 13th edition of this fantastic event was held on 14th March at the Hyatt Regency Hotel in Warsaw. The whole meeting was divided into four thematic parts. It made it full of discussions and the speeches called all the participants for reflection.

Discussion – first step to introducing changes…First part was started with the speech of Szy-mon Araszkiewicz, the director of consulting, Information Market/e-petrol.pl, who tried to face the problems in the Polish Fuel Market. He started with the analysis of last two years, which caused a heated discussion.

Discussants brought up the issue of low mar-gins due to high charges to the State (VAT, ex-cise tax, fuel charge), as well as the emergence of the so-called in Poland "gray zone" of indi-viduals and companies illegally dealing in fuel. It’s so difficult to solve problems like these…

But panel discussion engaging as many pro-fessionals is so important to exchange ideas.

Stop at the fuel station and stay there longer!The next part of the conference was started by Dominika Odejewska, the owner of the Ode-jewscy Center–the fuel station with many fa-cilities for travelers. She was talking about her

family’s business with so much passion. They have given an example how to make a great business. Dominika revealed how to deal with crisis managing the fuel station by providing full-service center for travelers! Apart from fuel station the Odejewscy Center is also:

Jakub Szelkowski, Barbara Pach 65


car wash, vulcanization’s center, restaurant, banquet halls, mini-ZOO, dinosaur park, chil-dren's playground and many others… They changed the fuel station from a come-refuel-pay-leave place to a travelers friendly center for everyone to stay in longer...

Moreover, she emphasized in her speech the great importance of reducing costs by invest-ing in renewable energy sources, reduce ener-gy consumption and water. That is exactly the key to success!

It’s time for freshness!It would seem that apart from Neste Oil there is no place for other players in Polish Mar-ket…nothing further from the truth!–told Michał Szymajda, head of network devel-opment at HUZAR during the third part of PetroTrend Fuel Forum. The network of Pol-ish Fuel Stations HUZAR is something new in

Polish Fuel Market and it is developing so fast nowadays. Raised in the block topics include: the situation of independent operators on the fuel market, working with corporations fran-chise, partnership, progress the consolidation of the independent stations, small stations problems – how to compete with the giants and survive.

Let’s debate with the representatives and the most influential companies!The last and the most exciting part of Petro-Trend 2013 was provided by the speeches of representatives of key companies in Poland, among others Bogdan Kucharski CEO of BP in Poland, Krzysztof Starzec director of fuel sector Statoil Fuel & Retail Poland, Paweł Maślakiewicz director of sales management

66 Let’s Shape the Fuel Market – PetroTrend 2013!

in LOTOS Group and Marek Balawajder, exec-utive director of retail sales of PKN ORLEN. The discussion was long but very construc-

tive. It was about state policy towards the oil sector, how to adapt to the new requirements and how to introduce regulatory changes.

The Fuel Station of 2013At the end of PetroTrend Fuel Forum 2013 was announced the results of the second edition of The Fuel Station of the year 2013 contest. The winner of the contest was chosen from the finalists in several categories and it was BP Port Świecko 39 in Poland.

Presence in this prestigious group of key fuel companies from the fuel market gave the chance to exchange experiences and opin-ions but first of all – it gave the chance to gain new or maintain current business rela-tions.

We could not miss such an important event, that is why our magazine was a Media Partner of PetroTrend 2013! It was great pleasure to be part of the event, we are looking forward to the

next edition of PetroTrend Fuel Forum. See you again in 2014!

Want to take part in creating ?

Join us!youngpetro.org/joinus

[email protected]

68

For information about advertising options:

youngpetro.org/ads or [email protected]

Call for Papers�YoungPetro is waiting for your paper!

Th e topics of the papers should refer to: Drilling Engineering, Reservoir Engineering, Fuels and Energy, Geology and Geophysics, Environmental Protection, Management and Economics

Papers should be sent to papers @ youngpetro.org

For more information visit youngpetro.org/papers

69

careers.slb.com





>110,000 employees

>140 nationalities


years of

innovation85


What will you be?

careers.slb.com





>110,000 employees

>140 nationalities


years of

innovation85


What will you be?

careers.slb.com





>110,000 employees

>140 nationalities


years of

innovation85


What will you be?

careers.slb.com





>110,000 employees

>140 nationalities


years of

innovation85


What will you be?

careers.slb.com





>110,000 employees

>140 nationalities


years of

innovation85


What will you be?

WInTer/SPrIng / 2013

WINTER/SPRING / 2013

ISSN 2300-1259

orga

nize

rs




Media Patronage






Republic of Poland

AGHUniv.

ofS

ci.

&Te

ch


and

Gas

Faculty*

Support

orga

nize

rs




Media Patronage






Republic of Poland

AGHUniv.

ofS

ci.

&Te

ch


and

Gas

Faculty*

Support

WIN

TER

/SPR

ING

/ 2

013

Documents

YoungPetro - 6/7th Issue - Winter/Spring 2013