Oil and Gas Exploration and Production in

western Greece and offshore Crete: Would we Succeed?

Associate Professor Vassilios C. KelessidisAssociate Professor Vassilios C. Kelessidis

Technical University of Crete

Cypriot-Greek Oil & Gas Summit 2012

Larnaca, June 14-15, 2012

Summary

• Western Greece area assessment and

problems encountered

• South Crete area assessment and

possibilitiespossibilities

• Very deep water & evaporite drilling:

issues and capabilities

• National technical and scientific

know-how

Prof. Georgalas (Un. Athens) speech in 1937 !

• Are there plenty of hydrocarbons in

Greece, and if yes, will we ever find

them?

• There is evidence which gives hope • There is evidence which gives hope

that oil and gas exist in some areas in

Greece…but

• …in order to answer fully the

question, we must drill many wells!3

Two phrases, Pythagoras and wildcatter

• ‘He who searches always finds, he

who does not search (dig!) will

never find’ – PYTHAGORASnever find’ – PYTHAGORAS

• Oil is… where you find it! -

WILDCATTERS

Western Greece

Oil seepsALBANIA

GREECE

2

345

6

78

109

1112

1314

15

17 16 18

21

20

192

1

Ioannina

Paxi-Parga

1Ii1

Ii2

I

192

2

3

1

4

5

1

23

3

2

1

1

2

Paxi-Parga

AitoloakarnaniaLevkas

Kefallinia

Zakynthos

31

2

NW Peloponnesos

4

Geographical distribution of

observed oil seeps in

western Greece.

Mavromatidis, Chania, 9/2011

Seismic and boreholes, Western Greece

7YPEKA, http://www.latomet.gr/HyrdoCApp/index.html

Deepest well, Paxoi, 1983!

8

Paxoi 1 & 1Χ1962 – 3179 m1983 – 5494 m

YPEKA, http://www.latomet.gr/HyrdoCApp/index.html

Oil groups of Western Greece

Nikolaou, Chania, 9/2011

Katakolo field, 1981

D. Nikolaou, Chania, 9/2011

Drilling activity1996 - 2001

ONSHORE WESTERN GREECE

• 1995, international bid for west Greece

• Until 2001, 5 land wells have been drilled

Demetra well

been drilled

– 2 Aitoloakarnania, ~ 1500 m

– 2 nw Peloponissos, ~ 2200 m

– 1 Ioannina, Demetra 1, ~ 3500 m

• All dry wells, with some oil shows

11Katakolo

Ioannina, 2001, Location & Visit

12

Demetra –1 & 1Ζ, IOANNINA

Company Enterprise Oil + Hell. Petrol.

Drilling Contr. ITAG, Rig 27

Start/Finish 8/9/2001 – 3/12/2001, 85 days.

Depth 3966 m & 3600 m

13

Depth 3966 m & 3600 m

Target possible reservoir below evaporites

Problems

High pressures, did not reach target – plug &

abandon

Regional Seismic LinesDemetra well

14

??

A. Mavromatidis, AAPG, 9/2007

Lithology and pressuresEvaporite interval

– 17.5 ppg (2.1gr/cm3)

Kick @ 3966m

– sidetrack

– 17.9 ppg (2.1g/cm3)

Kick @ 3566m

15

SIDETRACK

Prepared to encounter OP at

around 3900m onwards

Kick at 3566m,

Drilled with no problem in

original hole

Mavromatidis & Kelessidis, Mineral Wealth, 2011

Why? Causes of high pressures

Anomalously high pressure kick was totally

unexpected

No change in cuttings (anhydrite with dolomite

interbeds)

What is the pressure mechanism?What is the pressure mechanism?

� Young & Lepley (2005); Swarbrick et al. (2002)

o Fluid expansion ? Thermal effects, clay

diagenesis, HC maturation

o Tectonic Activity ? Cross along faults,

overthrust, compressional loading

� Change of lithology? Base of evaporites?

16Mavromatidis & Kelessidis, Mineral Wealth, 2011

High pressures close to change of lithology

• Overpressured fluid accumulations usually encountered immediatelyunderneath the evaporites

• Stringers. Overpressures in the stringers occur as a result of intra-stringer charge. Unfortunately stringers are difficult to be seen inseismic images.

• Hydrocarbon generation. No hydrocarbons in both wells. But if close tothe base of the evaporites, then gas can exert such pressures to theoverlying evaporites.overlying evaporites.

• Reached the detachment level -> overpressured sediments beneath theimpermeable evaporites characterized by extreme fluid overpressuring. Fluids ? water and/or gas.

17Mavromatidis & Kelessidis,

Mineral Wealth, 2011

Assessment – Demetra wells� Despite all pre-drilling preparations, unexpected high pressures can be

encountered.

� Proper post-drilling analysis could allow for assessment of causes of overpressure and better preparation for future drilling activity.

� Use of advanced drilling technology and the better formulation of drilling fluids, capable of operating with minimal problems under these harsh conditions.

Use better detection pore pressure mechanisms, ability to see ahead of bit.

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� Use better detection pore pressure mechanisms, ability to see ahead of bit.

� No well has ever penetrated the whole Triassic evaporitic strata in theIonian Zone.

� Drilling in western Greece should continue

� there are some 25 oil and gas fields in Albania,

� only one discovery has been made so far in western Greece (west

Katakolon)

� This is highly significant as it proves the existence of a viable play and its

continuation throughout western Greece

Assessment by D. Waters (9-11)• The Ionian zone in Greece & Albania is a proven HC province – good hunting ground.

• A large gas prone sub-thrust play may be regionally present under onshore Epirus.

• Analogues exist for the amounts of

High Risk High Reward

Sub-thrust

Prospectivity

Epirus NW Greece

• Analogues exist for the amounts of decollement displacement required to produce such a play.

• Need additional paleomagnetic studies on Paxos and Italian Apulia.

• Evaporite xenolith studies in Epirus, Gravimag, & seismic may provide additional de-risking.

Knowing which way to turn can sometimes be

difficult…

Substantial petroleum system –3 elements

Source rock

Excellent seal - Evaporites

RESERVOIR: Ionian carbonates reservoir

section,

Fractured Calci-turbidites and Debris flow

Reservoir rock

Enterprise Oil field trip, 2000

from A.Mavromatidis

What do we know about

south of Crete;

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Crete – Old Seismic

• Old technology

• Possible traps

• Unknown sediment thickness

Messara basin

thickness

• Existence of biogenic gas onshore in Messaraarea

22Hellenic Petroleum

Open bid – non-exclusive seismic

23

3 March 2012,

8 offers from very

reputable companies

We are waiting for the awarding

…Unofficial seismic? - 2004

24

Herodotus basin- Available data; TGS

http://www.tgsnopec.com/listallregiona

ldata.aspx?id=2464 12-June, 2012

25

Geological and Geochemical evidence

• Plate convergence

• Mediterranean Ridge with accretion

prismsprisms

• Active mud volcanoes emitting also

thermogenic gases

A. Foscolos, Heraklion, 2012

Chamot-Rooke N., C. Rangin, X. Le Pichon & Dotmed Working Group, 2005.

DOTMED – Deep Offshore Tectonics of the Mediterranean: A synthesis of deep

marine data in eastern Mediterranean, Mémoire de la Société géologique de France

& American Association of Petroleum Geologists, numéro spécial, 177, 64 pp, QA

http://www.geologie.ens.fr/IMG/jpg/CarteDotmed.jpg

Mediterranean

Ridge

Cz

Mz

50 km

Mz

Dr. E. Konofagos

Accretionary prisms &

hydrocarbon plays in

Barbados, Timor, Sinu Belt

30

From Zafeiropoulos, Hel. Petroleum, 2012

Hellenic trench

• unknown petroleum system

but possible based on

geology and biblio data

• insufficient seismic data

• very deep waters and difficult

sea bed morphology sea bed morphology

Mediterranean Ridge

• no definitive petroleum

system, but large sediment

thickness

• east and west sections very

interesting

• no seismic data

• academic data ���� possible

traps

Abyssal basins

• Herodotus basin most

probable oil bearing basin

• very few seismic data, not

enough to determine

structures

Potential problems

• Geopolitical

• Technical

• Environmental

Eastern Mediterranean EEZ (Kariotis)

Kastelorizo

AegeanSea

Cyprus

Turkey

Syria

Hellas

EGYPT

Kastelorizo

LIBYA

Cyprus

Lebanon

Israel

Hellas

Cyprus

Egypt

Israel

Lebanon

Syria

Turkey

Libya

Turkey’s claim for EEZ(Ozturk and Baseren, 2008)

Sea depth, south of Crete

Drilling through evaporite zones

• Excellent sealing properties! (a blessing and a curse?)

• Uncertainty on nature and interval beneath evaporites

• Possible high pressures difficult to • Possible high pressures difficult to predict in evaporite zones

• Seismic While Drilling has proven successful in different areas

• Safe drilling � continuous monitoring mud weight, tolerance between pore and fracpressures

• Aware of salt creep behavior

High pressures in evaporites

• Salt-water kicks have been encountered in Ukraine, Turkmenistan, Abu-Dhabi

• Causes? – no indications of approaching overpressure intervals

• Abu-Dhabi, anhydrite seals trapped • Abu-Dhabi, anhydrite seals trapped water from underlying reservoirs

• Ukraine & Turkmenistan, high pressure salt water kicks in evaporites�abandonment of several wells

• How about in South-East Mediterranean?

Knowledge Sharing

• Not much public information about drilling related problems in recent drilling activities (Leviathan, Tamar, Cyprus)

• Unofficial reports of several problems related to through-salt drillingrelated to through-salt drilling– washouts, stuck-pipe, clay layers

• Drilling fluids used? WBM and/or SBM?

• Any environmental issues to know off?

• Knowledge should be shared for upcoming drilling exploration activities in the area

Greek academic know how

• Local / national know-how important for supporting oil & gas exploration activities

• Small teams in different Universities

• Not a pure Petroleum Engineering Dept.

• Mineral Resources Engineering, TUC• Mineral Resources Engineering, TUC

• School of Mining and Metallurgical Engr., NTUA

• Geology Depts. (Athens, Thessaloniki, Patras)

• ΤΕΙ Kavala (Petroleum Technology)39

Overall picture, MRED - TUC

Drilling PVT Analysis

GeophysicsGeostatistics

Mineralogy

Engineering PVT Analysis

Hydrocarbon

Technology

Geochemistry

Rock

Mechanics

Reservoir

Simulation

& Analysis Petrography

Applied Geophysics

Main applications

• oil & gas exploration

•mineral exploration

• geotechnical engineering• geotechnical engineering

• subsurface water

• archeometry

• soil waste

• monitor construction quality

Hydrocarbons Chemistry and Technology

Applications�Crude oil & natural gas analysis

�PIONA analysis�Group type analysis�SimDist

Petroleum Geochemistry

�Analysis and interpretation ofbiomarkers

�Rock-Eval – total organic carbonanalysis

�Characterization of the

42

�SimDist�Analysis of asphaltenes

�Characterization of thedepositional environment

�Oil-oil and oil-sourcecorrelations

Drilling Engineering and Fluid Mechanics

Cuttings Transport

Pressure loss estimation

Non-Newtonian fluids

Drilling fluid properties

Additive development

43

0

500

1000

1500

2000

2500

0 0,002 0,004 0,006

Pre

ssu

re (

Pa/m

)

Q(m^3/sec)

Bentonite 1.85% DP - Q

Kelesidis

Measured

API

τy = 1.07 PaK = 0.0088 Pasn

n = 0.8798

Additive development

Rheology & Hydraulics simulator

PVT Lab & Reservoir Simulation

• Our lab has experience in applying numerical modeling

techniques for treating hydrocarbons phase behavior problems

• Collaboration with several labs of Schlumberger since 1996

• Tools have been developed for :

45

• Standard PVT analysis

• Multiphase flow metering

• PVT properties

• Reservoir simulation

Rock Mechanics Lab

� Measurement of mechanical properties

� Stability analysis of structures in geomechanics

(tunnels, slopes, wellbores, etc).

� FEM solutions of stress-strain problems in � FEM solutions of stress-strain problems in

geomechanics.

46MTS 815

(capacity 1600 kN)

Conclusions• Information for western Greece and south of Crete

• Many scientists believe that there are working petroleum systems in both areas

• More is known about west Greece, but where is the end of evaporites? (> 2 km)is the end of evaporites? (> 2 km)

• South of Crete is essential unexplored

• The much awaited seismic campaign will give essential information

• Prior drilling experience from south-east Mediterranean should be shared

• Scientific support from Greek Universities is available

Thank you !!! 48