Facies analysis in hydrocarbon exploration.A case study from NW Ionian Sea, Greece.

G. Makrodimitras; V. Kosmidou; S. Bellas.

Hellenic Hydrocarbon Resources Management S.A.

HHRM S.A.Hellenic Hydrocarbon Resources Management S.A.

Athens, Greecewww.greekhydrocarbons.gr g.makrodimitras@greekhydrocarbons.gr

AAPG Event: 15th-16th March 2018, Granada – GTW Series

Studied Area

Geological settingPre-Apulian zone Ionian zone

Well Data & limitationsAvailable data:

• 4 wells (East Ericoussa-1, Yanadhes-1, Paxi Gaios-1X and Parga-1).

• Legacy seismic lines & 2012 PGS lines to project well data.

• LAS files for 1 well only.

• Log data (GR, Sonic, Drilling porosity, resistivity, calcimetry).

• Lithology column from cuttings.

• Biostratigraphic data.

• Very basic core descriptions.

Limitations:

• No well from Apulian platform.

• Lack of LAS files for most of the well data

• Lack of basic log data e.g. NPHI-RHOZ for most of the wells.

• The description of carbonate rocks did not follow the Dunham’s

(1962) classification scheme

• Lack of vital sedimentological information such as: bioturbation

index, sedimentary structures, types of skeletal and non-skeletal

allochems, types of cements, clay content (kaolinite, illite or

smectite), types of porosity (1P, 2P, OP, BX, V, MO, μP, F) a.o.

WellSea Bottom

(m)Total Depth

(m)Analyzed by

HHRM

East Ericoussa-1 85.60 2392.00 ✓

Yanadhes-1 162.50 3951.00 ✓

Paxos Gaios-1X onshore 5494.00 ✓

Paxi-1 onshore 3179.00

Parga-1 102.00 3653.00 ✓

Parga-2 125.00 833.00

Thin-section descriptions

Descriptive framework & approach

Log Data & FAsShallow marine depositional environment:

Pliocene-Pleistocene deposits in East Ericoussa-1 and

Parga-1

Pliocene-Miocene deposits in Yanadhes-1 for Ionian Zone

UFS: Upper Shoreface

LFS.p: Proximal Lower Shoreface

LFS.d: Distal Lower Shoreface

OTZ: Offshore Transition Zone

B / OS: Basin / Offshore

DS: Debritic Sheet

Log Data & FAsContinental and coastal depositional

environments:

Pliocene-Pleistocene deposits in

Parga-1

FL.ch: Floodplain channel

FL.v: Floodplain valley

SW: Swamp

B/L: Bay/Lagoon

FLch

FLv

SW

B/L

WSS Signature

Facies Associations

Code

Deepwater clastic depositional environment

(turbidite fans):

Oligocene-Miocene deposits in East Ericoussa-1

The main issue in these kind of deposits is to

recognize from the log data if we are in a channel or

a lobe.

Typically the sandier deposits act like reservoirs. The

muddier deposits acts like source rocks or even seal if

they overlay a reservoir

CH: Channel fill

LS: Lobe sandsheets

LSf: Lobe fringe sandsheets

IS: Interlobe mudrock sheets

CGD?: Calcareous gravity mass deposits

Log Data & FAs

Log Data & FAsE/SB: Evaporites / Sabkha deposits

L/TF?: Lagoonal / Tidal flat deposits

BS: Base of Slope

OSS: Open sea shelf

East Ericoussa-1

Jurassic-Lower Cretaceous TriassicUpper Cretaceous-EocenePliocene-Pleistocene Oligocene-Miocene

DS

19.30%

UFS 3.67%

LSF.p 30.72

%

LSF.d

20.85

%

OTZ 25.45

%

CH6.29%

IS 85.78%

IS │ CGD?

3.62%

OSS 75.35%

OSS │ BS 24.65%

OSS 53.89%

L/TF? 46.11%

L/TF?

100.00%

Yanadhes-1

*Miocene interval includes repeated thrust series of Messinian, Langhian and Burdigalian.

**Upper Oligocene to Early Miocene (Aquitanian)

***Upper Cretaceous

Pliocene Miocene* Oligocene** ***Cretaceous

UFS?

2.46%

LFS.p

32.39%

LFS.d61.61%

OTZ

3.55%E

9.09% LFS.p7.51%

LFS.d74.50%

OTZ

8.01%

BS

67.32%

B

32.68% B 100.00%

Paxi Gaios-1X

TriassicJurassicPaleocene-Eocene Cretaceous

L/TF

12.24

% E

15.25%

E/SB 72.51%

B

8.39% BS 5.95%

L36.21

%L/TF

7.44%

E

42.00%

B

2.91%

BS

97.09%

BS

100.00%

Parga-1

Pliocene-Pleistocene Early MioceneMiddle MioceneLate Miocene

FLv6.76%

B/L

41.52%

LFS.p6.29%

OTZ

6.01%

OS

26.86

%OSS

100.00%

LS

3.34% IS

18.27

%

SL21.20

%

OSS57.18%

CH2.84%

LS

25.85%

LSf2.48%

IS68.83%

Pliocene-Pleistocene

DS 19.30%

UFS 3.67%

LSF.p 30.72

%

LSF.d 20.85

%

OTZ 25.45

%

Facies distribution in studied area

Pliocene

UFS?2.46%

LFS.p

32.39%

LFS.d

61.61%

OTZ3.55%

Pliocene-Pleistocene

FLv6.76%

B/L

41.52%

LFS.p6.29%

OTZ

6.01%

OS

26.86

%

Late Miocene

CH2.84%

LS

25.85%

LSf2.48%

IS68.83%

Early Miocene

OSS100.00%

Oligocene**

BS 67.32%

B

32.68%

Miocene*

E

9.09% LFS.p

7.51%

LFS.d74.50%

OTZ8.01%

Paleocene-Eocene

BS

100.00%

Middle Miocene

LS

3.34% IS

18.27

%

SL21.20

%

OSS57.18%

MSC

Upper Cretaceous-Eocene

OSS 75.35%

OSS │ BS 24.65%

Triassic

L/TF? 100.00%

***Cretaceous

B 100.00%

Triassic

L/TF

12.24

% E

15.25%

E/SB 72.51%

Jurassic-Lower Cretaceous

OSS

53.89%

L/TF?

46.11%

Jurassic

B

8.39% BS 5.95%

L36.21

%L/TF

7.44%

E

42.00%

Cretaceous

B

2.91%

BS

97.09%

Lias

sic

Even

t

Oligocene-Miocene

CH6.29%

IS 85.78%

IS │ CGD?

3.62%

Basin fillForeland basin Piggy-Back basin

(ex Foreland)

E/SB

L/TF

OSS/BS

ISCHLSLSf

CGDOSSSL

UFSLFS.dLFS.pOTZDS

BBS

UFSLFS.dLFS.pOTZ

LFS.dLFS.pOTZDSE

B

Basin fill

Foreland basin & Platform

UFSLFS.dLFS.pOTZSL

OSFLdFLvSWB/L

ISCHLSLSf

OSS

B/BS

E/SB

L/TFE

B/BS

• Re-interpretation of core descriptions, well data, biostratigraphic data & integration with seismic data Depositional environments & FAs

• Variety of depositional environments with their FAs in studied area.

• Some of these FAs typically exhibit better reservoir quality properties (e.g. CH, LS, UFS), others not (e.g. E, IS).

• Lateral extent of these FAs is challenging and high risky with the available data but necessary for the RQ analysis studies.

Recommendations:

• Denser, HQ or 3D seismic data can better image any lateral extent of FAs.

• Detailed core and cuttings descriptions, with application of Dunham’s classification scheme (for carbonates) provide framework to undertake RQ analysis.

• Biostratigraphy is a critical tool-strong evidence of the depositional environment, which needs to be applied and integrated with well data.

• Thin-section/SEM descriptions from cuttings and plugs and CCA data to eliminate ambiguities and specify fabrics, mineralogical components, clays, cements

and pore types, foraminifera sets and diagenetic overprint strong impact on reservoir quality/pore network (in case of reservoir) and basin modeling.

• The aim of this kind of studies is to highlight FAs potential geometries, heterogeneities and baffles Distinguish Basin Fill assess the timing of

hydrocarbon charge and diagenesis, bitumen distribution.

Conclusions

Thank you!

Gracias!

HHRM S.A.Hellenic Hydrocarbon Resources Management S.A.

Athens, Greecewww.greekhydrocarbons.gr g.makrodimitras@greekhydrocarbons.gr

!