Depositional Environments and Hydrocarbon Potential of ... · Depositional Environments and Hydrocarbon Potential of Northern Ionian Sea Vasiliki Kosmidou George Makrodimitras Nick

Hellenic Hydrocarbon Resources Management S.A. AAPG Granada 2018

Depositional Environments and Hydrocarbon Potential of

Northern Ionian SeaVasiliki Kosmidou

George Makrodimitras

Nick Papatheodorou


Contents

❖ Area of Interest

❖ Studied Dataset

❖ Workflow

❖ SWIT and Paleolatitude

❖ Heat flow

❖ BHT and Vitrinite Reflectance Data

❖ Geochemical Data

❖ Erosion, Uplift and Flexural Rigidity

❖ 3D model

❖ Paleoenvironments

❖ Conclusions


Area of Interest

❖ Northern Ionian sea is the greater area of western Corfu and Paxos islands in Offshore Western Greece.

❖ Geologically, the area is bounded to the north by the Otranto Basin and to the south by the Kefalonia strike-slip fault.

❖ On the west there is the Apulian escarpment and from there westwards starts the Calabrian Ridge. On the east, there is the deep basinal area, the South Adriatic Basin, that is bounded on its eastern margin by the front of the Hellenides thrust-and-fold belt.

❖ The central part of the basin is the Apulian platform.

Apulian Platform


Studied Dataset

6000km 2D seismic data (approx.)

2D multiclient seismic survey (2012, PGS)

Legacy seismic surveys

4 wells

Paxi-Gaios 1X

Paxi 1

East Erikousa 1

Yannadhes 1

Yannadhes

Paxi 1Paxi Gaios 1X


Workflow

SURFACE GRIDS

Interpret key horizons in TWT. Depth conversion using sonic data.

THERMAL PARAMETERS

Sediment water interface temperature diagram from Wygrala (1989).

Paleolatitude for Ionian Sea based on Torsvik et al. (2012).

Heat flow scenario based on analogue cases and reference studies. Calibration

data available from the AOI.

ORGANIC GEOCHEMISTRY

Rock eval data from AGIP Rock - Eval Report for Paxi-Gaios 1X samples for Kerogen Type categorisation and source rock quality estimation

MODEL

Depth converted horizon grids used in a 3D model with Haq's (1987)* sea level curves. Tectonic uplift, subsidence and sediment compaction were not modelled.

EROSION, UPLIFT AND FLEXURAL RIGIDITY

Erosion identification in seismic. Uplift scenario from literature. Flexural rigidity of 1023Nm (Allen & Allen, 2013)

* Modified by Miller, 2005


SWIT and latitude changes

Time(Ma)

Lati

tud

e(o

)

Modified from Wygrala (1989)

North Ionian Sea

>30oC25-30oC

15-20oC

10-15oC<5oC5-10oC

20-25oC

25-30oC


Heat flow scenario


BHT and Vitrinite Reflectance Data


Gas SR

Gas SR ?

Very Little SR or no SR


Erosion• Seismic data suggest important erosional unconformities in

the AOI.

: Three intra-carbonate erosional unconformities (also observed in Italian outcrops). In the basinal areas unconformities are observed due to the introduction of calciturbidites in the basin.

: Three main erosional unconformities in the Miocene sequence with the later and more important one the messinian unconformity.

: Three Mass Transport Complexes associated with earthquake and thrust activity.

500 m

Cretaceous intra-carbonate unconformities

Pliocene-Pleistocene MTC

Miocene unconformities


Flexural Rigidity

o Uplift started in middle Pleistocene (Doglioni et al., 1994) associated with the deposition of two loads on the margins of Apulia. This, together with the KTF and isostasy, affected the geometry, tension and pressure profile of the AOI.

o In the Middle Pleistocene, the platform was uplifted while the adjacent basinal areas were affected by subsidence (Mastronuzzi et al. 2011).

o Uplift rates from 0.4 to 0.2 (0.5 -0.7) mm/yr (Cianrafi et al. 1988; Doglioni et al., 1994).

o Allen & Allen (2013) suggest a displacement of the fore bulge towards Apennines by asymmetry of flexural rigidity of Adriatic.

o Hellenides D= 1023 Nm

o Apennines D= 6 * 1022 Nm

o The maximum deflection is assumed w0=10km

Uplift and Flexural Rigidity

(From Allen & Allen, 3rd, 2013)

Uplift


Terrestrial to shallow marine environment

Triassic

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120 140 160 180 200

?Neotethys

A-B


TriassicHigh Slopes indicative of Rifting

Restricted basinal,marine environment adjacent to

the carbonate platforms where we expect the deposition of formations

equivalent to Burano Fm.

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120

C-D


Jurassic


Jurassic


Jurassic


Jurassic


Extensive platform

Jurassic

Topographic highs that favour the

development of Build Ups

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120 140 160 180 200

A-B


Jurassic

Rimmed Platform

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120

C-D


Early Cretaceous


Early Cretaceous


Early Cretaceous


Early Cretaceous

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120 140 160 180 200

Isolated build-ups

A-B


Early Cretaceous

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120

Extensive platform

Isolated build-ups

C-D


Late Cretaceous


Late Cretaceous


Late Cretaceous

Carbonate Build-Ups covered by pelagic sediments


Late Cretaceous

Subaerial erosion of the carbonate platform led to the development of calciturbidites transferred into the

basin impeding the carbonate build up development

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120 140 160 180 200

A-B


Late Cretaceous

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120

Steep platform slope and intense erosion leads to

redeposited carbonate sediments in the slope

and proximal basin

C-D


Paleogene

Prograding sediment infill from the east/ thrust propagading


Paleogene



Paleogene



Paleogene



Paleogene



Miocene



MessinianHighest slopes at the eastern

margin match the seismic interpretation suggesting higher

sediment infill from the east


Messinian

Messinian Salinity CrisisSea Level Drop


Messinian



Messinian



Messinian



Messinian



Messinian



Messinian

Zanclean Flooding


Messinian

Zanclean Flooding


Messinian

Zanclean Flooding


Messinian

Zanclean Flooding


Messinian

Zanclean Flooding


Messinian

Zanclean Flooding


MessinianHighest slopes at the eastern

margin match the seismic interpretation suggesting higher

sediment infill from the east

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120 140 160 180 200

A-B


Messinian

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120

Highest slopes at the eastern margin match the seismic

interpretation suggesting higher sediment infill from the east

C-D


Plio - Pleistocene

Excessive deepening due to the KTF and the

Uplift


Plio - Pleistocene


Uplift


Plio - Pleistocene


Uplift


Plio - Pleistocene


Uplift


Plio - Pleistocene


Uplift


Plio - Pleistocene


Uplift

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120 140 160 180 200

A-B


Plio - Pleistocene

-1500

-500

500

1500

2500

3500

0 20 40 60 80 100 120

C-D


-1500

-1000

-500

0

500

1000

1500

2000

2500

3000

3500

0 20 40 60 80 100 120

-1500

-1000

-500

0

500

1000

1500

2000

2500

3000

3500

0 20 40 60 80 100 120

Lateral Migration of the basin depocenter from Jurassic to Present

(C-D)


Paleoenvironments


Conclusions

❖ North Ionian Sea is characterized by a wide shallow water platform with occasionally steep slopes to the west and a deep basin to the east

❖ In the basinal part, three isolated carbonate build ups can be identified in the 2D seismic

❖ Rock-Eval data suggest good to excellent source rocks

❖ Paleothermal data suggest necessary conditions for the maturation of hydrocarbons in the past

❖ 3D model allowed the identification of high slope areas indicating the best locations for the development of bioclastic slope aprons and the location of carbonate build-ups

❖ 3D model helped the understanding of the lateral change of the basin depocenter due to the thrust activity


Questions?

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Depositional Environments and Hydrocarbon Potential of ... · Depositional Environments and Hydrocarbon Potential of Northern Ionian Sea Vasiliki Kosmidou George Makrodimitras Nick