Ppt assgn 1

Problem Solving :Water Flood for Oil Production

GROUP 11

ALIF NUZULUL HIDAYAT (1206249832)DIDIK SUDARSONO (1206242555)ENI MULYATININGSIH (1206201971)RAHGANDA (1206261182)SYLVIA AMANDA S (1206241230)

OUTLINE

INTRODUCTION (Background, Project Objective, Plant Condition, Basic Theory)

PROCESS SYNTHESIS(Alternative Process, Process Selection, Process Description, BFD, PFD)

MASS AND ENERGY BALANCE (Mass Balance, Energy Balance, Simulation)

INTRODUCTION - BACKGROUND

• Reservoir pressure in Kerisi has started to decline Enhanced Oil Recovery (EOR) will be conducted to lift the remaining oil in the well.

• Based on studies by ConocoPhillips, EOR method chosen for Kerisi field is waterflood.

• Waterflood will be done by injecting seawater taken from well K-14 to K-13 well.

• Oil and gas reservoir that will be injected by seawater contains no H2S gas

• Waterflood by injecting seawater into the formation will lower the temperature of the reservoir to a temperature level that is conducive to the SRB activity

INTRODUCTION - BACKGROUND

• Two methods of seawater pre-treatment to be considered today are sulphate removal membrane and nitrate injection.

• The selection is not only based on its ability to reduce H2S in the product, but also considering the limited space available on the platform and also the cost required to install the pre-treatment facility.

INTRODUCTION – PROJECT OBJECTIVE

• To make a preliminary design of a seawater treatment plant to meet the specifications of seawater injected into the well K-13 in order to perform the waterflood to reservoir.

• To choose the most appropriate method to avoid the formation of H2S by SRB which are the main problem that can occur due to the waterflood

• To estimate the cost required to install the process facilities which are needed for seawater treatment

INTRODUCTION – PLANT CONDITION

INTRODUCTION – PLANT CONDITION

INTRODUCTION – PLANT CONDITIONComponent Concentration in raw seawater

K1+, mg/l 293

Na1+, mg/l 10493

Mg2+, mg/l 1150

Ca2+, mg/l 351.1

Cl1-, mg/l 18387

SO42-, mg/l 2671

HCO31-, mg/l 93

TDS, mg/l 33458

pH 8.3

TSS, mg/l 15-20

Temp., °C 20

Oxygen, mg/l 5-8

INTRODUCTION – BASIC THEORY



Mechanism of Sulfate Reducing Bacteria (SRB)

Dissimilatory sulfate reduction occurs in three steps:• Conversion (activation) of sulfate

to Adenosine 5’-phosphosulfate (APS)

• Reduction of APS to sulfite• Reduction of sulfite to sulfide

PROCESS SYNTHESIS

Basic Mechanism

Alternative Process : • Sulfate Removal Membrane • Nitrate Injection

PROCESS SYNTHESIS - SULFATE REMOVAL MEMBRANE

• Objective: reduce sulphate as main food supply for SRB


• The process for removing sulfate ions from seawater is based on nano-filtration (NF) membrane separation.

• NF is a membrane process that selectively removes sulfate ions to produce seawater with low concentration sulphate (20-40 ppm).


Advantages Disadvantages

• High quality injection ion sulphate from water

• Reduction in need for biocides

• Reduction of scaling

• More effective squeeze treatments

• Assists control of bacterial (sulphate reducing bacteria) well souring

• Lower operating costs and increases productivity

• Degrade very quickly upon exposure to free chlorine

• Use of DBNPA or equivalent biocide be considered to prevent biological fouling.

• Must add anti-scale to prevent calcium scaling. • Need high CAPEX to buy the sulphate

removal membrane. • < 40 mg/L ion sulphate CAPEX is

$20MM USD • < 30 mg/L ion sulphate incremental

CAPEX $103,000 USD; need higher spec membrane.

PROCESS SYNTHESIS – NITRATE INJECTION

Facilities Process

1. Added NaOCl in order

2. Passing through course filter (range 50 - 2000 μm.

3. Passing through Multimedia filter (<40 micron)

4. Oxygen Scavenger or de-aeration

5. Injection of chemical compounds:• Nitrate • Biocide • Corrosion inhibitor

• Objective : bio-competition, to reduce food supply for SRB

PROCESS SYNTHESIS – NITRATE INJECTION

Advantages Disadvantages

• Cheap nitrate price, around 30 US Dollar per ton to get 45% of Ca(NO3)2.

• Can clean soured reservoir with gradually injection up to 100 ppm nitrate ion to facilities.

• Simple usage,

• Safe to use, not caused damage to environment and potential for microbial EOR.

• Water treatment facilities need to be constructed with non-iron material.

• Reservoir performance can be lower as there is permeability reduction to bacterial colonies in critical flow passages.

• There are no significant dosage of nitrate for injection and also every well will has different dosage depend on condition

PROCESS SYNTHESIS – PROCESS SELECTION

Rating

Criteria Performance

to Prevent H2S Production

Space Required

Corrosion Effect to Sub-

Surface Facilities

Easy to Operate Investment Cost

Environment Effect

Weight

(%)30 25 15 10 15 5

1More than 600

ppm H2S concentration in

10 year

Require very large spacing ( > 4000 m2),

so must require expansion platform

Contain corrodent (O2, acid, bacteria) and electrolyte

with high concentration

Cannot operate automatic, always

change parameter of composition in

chemical injection and often

maintenance

More than $40 million

Very dangerous for environment,

chemical injection is

strongly hazardous

and explosive

2600 ppm-300


10 year

Require large spacing (4000 -

3000 m2), so must require

expansion platform

Contain corrodent (O2, acid, bacteria)

with low concentration and electrolyte

with high concentration

Cannot operate automatic, sometime change parameter of

composition in chemical injection

and often maintenance

$40 million - $30

million

Dangerous for environment,

chemical injection is

strongly hazardous

3300 ppm -100


10 year

Require middle spacing (3000-2000 m2), so must require

expansion platform

Contain corrodent (O2, acid, bacteria) and electrolyte

with low concentration

Cannot operate automatic, sometime change parameter of

composition in chemical injection

and seldom maintenance

$30 million - $20

million

Less dangerous for environment,

chemical injection is bit

hazardous


Rating

Criteria Performance

to Prevent H2S Production

Space Required

Corrosion Effect to Sub-

Surface Facilities

Easy to Operate Investment Cost

Environment Effect

Weight

(%)30 25 15 10 15 5

4100 ppm -50 ppm H2S concentration

in 10 year

Require narrow spacing (2000-1000 m2), not

require expansion platform

Not contain corrodent (O2, acid, bacteria),

but contain electrolyte

Can operate automatic, sometime change parameter of

composition in chemical injection and seldom maintenance

$20 milion - $10 milion

No-negative environmental

. chemical injection is less

hazardous

5Less than 50 ppm H2S concentration

in 10 year

Require very narrow spacing (< 1000 m2), not

require expansion platform

Not contain corrodent (O2, acid, bacteria)

and electrolyte

Can operate automatic, seldom

change parameter of composition in

chemical injection and seldom maintenance

Less than $10 milion

No-negative environmental

. chemical injection is not

hazardous


Parameter Weight (%)

Sulphate Removal

Membran

Weight Score

Nitrate Injection

Weight Score

Performance to prevent H2Sproduction

30 5 1.5 4 1.2

Space required 25 2 0.5 4 1Prevent corrosion on sub-surfaceFacilities 15 4 0.6 2 0.3

Investment Cost 15 2 0.3 4 0.6

Ease to Operate 10 2 0.2 4 0.4Environment Effect 5 4 0.2 5 0.25

Total 100 3.3 3.75

PROCESS SYNTHESIS - BLOCK FLOW DIAGRAM

Figure 2.17. Vacuum Stripping De-aeration

PROCESS SYNTHESIS - PROCESS DESCRIPTION

Capacity waterflood : 50.000 barrel or 339000 kg/h

Capacity seawater : 741000 kg/h

Waterflood Characteristic


1. Pre-Primary Filtration

• Basin is a reservoir of seawater to be pumped.

• Basin serves to prevent floating dirt is not carried into seawater lift pump.

• A deeper intake is aim to get sea-water that contain low TSS, low oxygen, low temperature and consistent water quality

• In basin, seawater is injected sodium hypochlorite () that is produced in hypochlorite generator.

Figure 2. 8. Basin Structure for Pre-Primary Filtration


1. Pre-Primary Filtration

• Raw material : Seawater

• Process : Electrolysis (In Situ)Anode : Cathode : Overall :

Figure 2. 9. Hypochlorite Generator


2. Primary Solid Removal

• Remove suspended solid (> 100 µm) with 98% efficiency.

• Type : Dead End Filtration • Flow capacity up to 2270 GPM (619 m3/h)• If pressure drop is high, flush process start

to clean the solid that is restrained.

• Flush process can operate automatic.

Raw Water Inlet Filtered Water Outlet

Sludge Outlet

Figure 2.10. Coarse Strainer Unit


3. Secondary Solid Removal

• Remove suspended solid (> 2 µm) with 98% efficiency. (high turbidity in seawater)

• Type : Granular Filtration • Flow capacity up to 425 m3/h• Backwash : Clean the bed, High pressure

drop• The ideal backwash rate is 250-450 m3/h.

Figure 2.11. Multi Media Unit

Raw Water Inlet

Filtered Water Outlet

Sludge Outlet

Backwash Inlet

AnthraciteFine Garnet

Coarse Garnet


4. De-aeration• Remove oxygen in seawater (< 50 ppb) • Type : Vacuum Stripping De-aeration • Equipment : De-oxygenation tower, Ejector,

Vacuum Pump, Separator. • Principle : o Partial pressure of oxygen in water is a

function of the total pressure of the system.o Vacuum the system can reduce the partial

pressure of oxygen and make driving force for mass transfer of oxygen from the liquid to the gas phase.

Figure 2.17. Vacuum Stripping De-aeration


6. Chemical Injection PackageChemical Dosage Treatment Application Injection Point

Scale Inhibitor 20 ppm First, 200.000 bbls of water injection

Inhibits CaCO3 scale Discharge seawater lift pump

Calcium Nitrate 100 ppm Continuous Microbial control by bio-competition

Suction of water injection pump

Biocide THPS 200 ppm Batch, Once a week for 4 hours

Microbial control Suction of water injection pump

Oxygen Scavenger 10 ppm Continuous, Reduce oxygen to low concentration

Exit of de-aerator

Corrosion Inhibitor 30 ppm Continuous, To prevent corrosion in subsurface facilities

Suction of water injection pump

PROCESS SYNTHESIS - PROCESS FLOW DIAGRAM

PROCESS SYNTHESIS - PROCESS FLOW DIAGRAMStreams

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17Mass Flow Rate (kg/h) 741,523 741,498 88,979 24.22 339,309 339,308 33,058 33,060 339,305 2.66 339,305 4.79 40.48 1.79 32.41 339,384 339,384

Pressure (bar) 7.10 7.01 7.01 7 7.01 7.01 1.01 1.01 7.10 7.10 17.01 1.01 1.01 1.01 1.01 1.01 125.01Temperature (C ) 25.06 25.06 25.06 25.10 25.06 25.06 25.00 25.00 25.06 25.06 25.10 25.00 25.00 25.00 25.00 25.10 25.63Alga (% mass) 0.0005 0.0005 0.0005 0.0003 0.0005 0.0000 - 0.0049 0.0000 - 0.0000 - - - - 0 0

Solid (% mass) 0.0015 0.0000 0.0000 10.9000 0.0000 0.0000 - 0.0003 0.0000 - 0.0000 - - - - 0 0

TDS (% mass) 3.25 3.25 3.25 0.43 3.25 3.25 3.25 3.25 3.25 - 3.25 - - - - 3.24 3.24

NaOCl (% mass) 0.00001 0.000001 0.000001 0.000001 0.000001 0.00000 - - 0.00000 - 0.00000 - - - - 0 0

Oxygen (% mass) 0.0008 0.0008 0.0008 0.0000 0.0008 0.0008 0.0008 0.0008 0.0000 100.00 0.0000 - - - - 0 0

Water (% mass) 96.74 96.74 96.74 53.21 96.74 96.74 96.74 96.74 96.74 - 96.74 - - - - 96.74 96.74

Na2SO3 (%mass) - - - - - - - - - - - 40 - - - 0.0006 0.0006Water (% mass) - - - - - - - - - - - 60 - - - - -Ca(NO3)2 (% mass) - - - - - - - - - - - - 45 - - 0.0054 0.0054

Water (% mass) - - - - - - - - - - - - 55 - - - -THPS (% mass) - - - - - - - - - - - - - 50 - 0.0003 0.0003Water (% massa) - - - - - - - - - - - - - 50 - - -Cyclo-hexylamine (% mass) - - - - - - - - - - - - - - 13 0.0012 0.0012

Morpholin (% mass) - - - - - - - - - - - - - - 7 0.0007 0.0007

Water (% mass) - - - - - - - - - - - - - - 80 - -

PROCESS SYNTHESIS - PROCESS FLOW DIAGRAM

MASS AND ENERGY BALANCE – MASS BALANCEMass Balance Inlet for Overall Processes

Inlet Stream Mass Flow (kg/hr) Inlet Component Mass Flow

(kg/hr)

Seawater (Feed) 741,522.87

H2O 717,402.61Oxygen 5.93

Dissolved Solid 24,099.49Suspended Solid 14.83

NaOCl 18 0.23 NaOCl 0.23

Chemical Injection Package

12

79.47

Oxygen Scavenging Chemical 4.79

Calcium Nitrate Solution 40.4813

Biocide Solution 1.791415 Corrosion Inhibitor 32.41

Total 741,602.57

(Source: Author’s personal data)

MASS AND ENERGY BALANCE – MASS BALANCEMass Balance Outlet for Overall Processes


Outlet Stream Mass Flow (kg/hr) Outlet Components Mass Flow

(kg/hr)

Injected Seawater 16 339,384.98

H2O 328,329.49Oxygen 0.05


Oxygen 10 2.66 Oxygen 2.66

Utility Water 3 88,979.86

H2O 86,086.77Oxygen 0.71


Disposed Seawater

313,235.06

H2O 303,038.314 and 8 Oxygen 2.51

Dissolved Solid 10,179.97 Suspended Solid 14.27

Total 741,602.56

MASS AND ENERGY BALANCE – ENERGY BALANCE


[Energy In] – [Energy Out] = [Accumulation of energy]

Inlet Stream Heat Flow (MJ/h) Outlet Stream Heat Flow

(MJ/h)

Seawater 77,423.15 Injected Seawater 17 36,322.63

NaOCl 18 0.01 Oxygen 10 0.06Pump 1 191.16 Backwash 8 32,783.85Pump 2 60.19 Utility Water 3 9,313.59Oxygen

Scavanging Chemical

12 0.36

Calcium Nitrate 13 2.63Biocide 14 0.38

Corrosion Inhibitor 15 2.99

Total 78,427.17 Total 78,421.69Pump 3 746.28 Sludge 4 1.56

MASS AND ENERGY BALANCE – ENERGY BALANCE

Mass Efficiency

Energy Efficiency

NEED FOR MASS AND ENERGY

To produce 50,000 BWPD for waterflood, it needs

108,667 barrels water per day in the feed, and

3 pumps with total power 1669 kW

MASS AND ENERGY BALANCE – SIMULATION

• Using SuperPro

CONCLUSION1. Process of Enhanced Oil Recovery (EOR) will be conducted to lift the remaining oil

from Kerisi well with water flood method.

2. Design for the process need to meet criteria such as reduce amount of content that may cause problem in well like TSS, sulphate ion, and oxygen from seawater, facilities can be placed on available area and should be as economical as possible.

3. Parameters that will be used in process selection are performance to prevent H2S production, space limited, corrosion effect, investment cost and environment.

4. Process selected for seawater for injection well is nitrate injection process which is used calcium nitrate with concentration 100 ppm to process water.

5. There are several main section of this plant as follow pre-primary filtration, primary solid removal with coarse strainer, secondary solid removal with multimedia filter, de-aeration and chemical injection package.

6. We simulate the overall process using SuperPro Software and processing the data to calculate mass and energy balance. It needs 108,667 barrels water per day or equivalent to 741,522 kg/h to produce 50,000 barrels water per day to fullfill demand of waterfloods in the oil well. For energy needs, we will have three pumps with total power 1669 kW.

Injection of 50,000 bpd of seawater will likely increase the H2S level in the production system to around 600 ppmv in 10 years. The increase of H2S is caused by several factors:

Decrease in Reservoir temperature

over time.

High (dissolved organic carbons)

DOC in produced water. High Sulphate in the Seawater. Bacteria availability from the seawater.

THANK YOU

Engineering

Ppt assgn 1