Evolution of the Lower Cretaceous carbonate ...

Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs, in Central Moesian Platform, Romania.

Adriana Raileanu*, Ion Stefan Popescu, Aurelia Liliana Stan, Roxana Dudus

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Presentation name

Chapter name

• Objectives 1. Controlling factor on Lower Cretaceous carbonate ramp evolution, Central-Eastern Moesian Platform 1.1. Carbonate platform type 1.2. Standard microfacies and facies zone 1.3. Paleobathimetry, paleoecology 1.4. Basin energy index 1.5. Carbonate factory, climate-temperature

Study area location on the Moesian Platform

2. Defining of Lower Cretaceous carbonate depositional systems in order to predict reservoir properties 2.1. Lower Cretaceous carbonate ramp characteristics on 2D seismic lines 2.2 Carbonate ramp restoration and conceptual depositional interpretation 2.3. Correlation of the carbonate depositional systems on well logs 2.4. Depositional model and associated facies 2.5. Lower Cretaceous seismic-sequence stratigraphy

3. Controls on carbonate reservoirs quality 3.1. Reservoirs related to differentiated compaction on the outer/median ramp boundary or on the reef/shoal-bank flanks 3.2. Reservoirs related to the karstic-fissure systems 3.3. Reservoirs related to organic reef or microbial-algal activities 3.4. Reservoirs related to carbonate shoals - banks or channels 3.5. Evolution Reservoirs related to diagenetic processes due to subaerial exposure of the Lower Cretaceous carbonate name sequences and depositional control on hydrocarbon reservoirs Presentation name Chapter 2

2D seismic lines grid.

• Methods and data

EVIDENCE -from known producing area Well data (cores, logs) Core lithology Core biostratigraphy Core petrography Core sedimentology

……………………….. Well log pattern Well log correlation Seismic events on logs

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2D seismic lines (reefs, shoals/banks, channels)

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Boundary configuration of the Strattal terminations Seismic facies changes Drape presence Velocity anomalies Spurious events Position in the basin architecture

GUIDANCE from:

FACIES MODELS used as Norm for future observation, basis for interpretation

Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs Presentation name

PREDICTION IN NEW AREA

Depositional systems and subsystems Characteristic facies Reservoir qualities

• Stratigraphic setting - Lithostratigraphy - Biostratigraphy

Lower Cretaceous lithostratigraphy and major depositional domains.

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Upper Jurassic-Lower Cretaceous in Evolution of the Lower Cretaceous carbonate sequences and depositional chrono-biostratigraphy control on hydrocarbon reservoirs Presentation name Central- Eastern Moesian Platform.

• Tectonic setting

Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs Presentation name 5 Tectonic sketch of the Central - Eastern Moesian Platform (after CCPEG interpretation, 2004).

1. Controlling factor on Lower Cretaceous carbonate ramp evolution -1.1. Carbonate platform type

E

W 200 ms

1176 m West-East regional seismic lines, carbonate flattened at Pre-Neogene showing the morphology of the Lower Cretaceous carbonate Evolution of the Lower Cretaceous sequences and depositional control on hydrocarbon reservoirs Presentation name 6 ramp and gradually transition of the median ramp to outer ramp (1 and 2).

1. Controlling factor on Lower Cretaceous carbonate ramp evolution - 1.2. Standard microfacies and facies zone (adapted from Wilson, L.J. 1974, Read, J.F. 1985, Tucker, M. 1998)

No scale

Relationship between characteristic facies, carbonate ramp and oil field distribution in the Central-Eastern Moesian Presentation name 7 Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs Platform.

1. Controlling factor on Lower

Cretaceous carbonate ramp evolution

BARREMIAN - APTIAN

-1.3. Paleobathimetry–paleoecology HAUTERIVIAN

-200 m

-75 m

Paleobathimetry and paleoecology based on ammonoids, bryozoans, bivalves, rudists, vermes, sponges, gastropods distribution, Hauterivian (left) and Barremian-Aptian (above) carbonate ramp.

m -2008m Presentation-75 name

1. Controlling factor on Lower Cretaceous carbonate ramp evolution - 1.4. Basinal energy index

OUTER RAMP

MEDIAN RAMP

INNER RAMP

Spatial distribution of energy index values on the cabonate ramp, Barremian - Aptian.

(Plumley classification, 1962)

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Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs Presentation name

Relationships between ramp depositional systems, carbonate types and basinal energy.

1. Controlling factor on Lower Cretaceous carbonate ramp evolution -1.5. Carbonate factory, climate - temperature

Spatial distribution of insoluble residue values on the carbonate ramp, Barremian - Aptian.

Aridity curve based on Classopolis abundance 10

(after I. S. Popescu, 2005, Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs Presentation name A. L. Frakes, 1979).

2. Defining of Lower Cretaceous carbonate depositional systems in order to predict reservoir properties - 2.1. Lower Cretaceous carbonate ramp characteristics on 2D seismic lines

200 ms

200 ms

200 ms

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Presentation Evolution of the Lower name Cretaceous Chapter carbonate sequences name and depositional control on hydrocarbon reservoirs

2. Defining of Lower Cretaceous carbonate depositional systems in order to predict reservoir properties - 2.2. Carbonate ramp restoration and conceptual depositional interpretation

Presentation Evolution of the integrated Lower name Cretaceous Chapter carbonate sequences name of andthe depositional on hydrocarbon reservoirs 12 sequential Balanced, interpretation Lowercontrol Cretaceous depositional systems.

2. Defining of Lower Cretaceous carbonate depositional systems in order to predict reservoir properties - 2.2. Carbonate ramp restoration and conceptual depositional interpretation

Presentation name Chapter name of the Lower Cretaceous depositional systems. 13 sequential Balanced, integrated interpretation

2. Defining of Lower Cretaceous carbonate depositional systems in order to predict reservoir properties - 2.3. Correlation of the carbonate depositional systems on well logs W

name 14 Presentation West-East well log correlation on outer and median ramp showing depositional systems and major facies distribution.

E

2.4. Berriasian-Hauterivian depositional model and associated facies

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Chapter name

2. Defining of Lower Cretaceous carbonate depositional systems in order to predict reservoir properties 2.4. Berriasian-Hauterivian depositional model and associated facies Rudstone, channel Cor-algal boundstone, patch reef Lumpal-algal grainstone, patch reef

262 Serdanu

285 Tancabesti 134 Corbii Mari

Algal boundstone, median ramp

Pelletal-ocoidal grainstone, lagoon

Skeletal wackestone, outer ramp

278 Vanatori 2243 Caldararu

0,01 cm

1411 Domensti Skeletal algal grainstone, shoal

264 Bragadiru

Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs name 16 Presentation

2.4. Barremian-Aptian depositional model and associated facies

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Presentation name

Chapter name

2. Defining of Lower Cretaceous carbonate depositional systems in order to predict reservoir properties 2.4. Barremian-Aptian depositional model and associated facies Oolitic-oncolitic grainstone, shoal Algal-intraclastic packstone, inner ramp

Oncolitic grainstone, shoal

Skeletal packstone, bank

Ba-Apt

263 Serdanu 1449 Gastesti

275 Baldana

Pelletal grainstone, lagoon Patch reef 1671 Valea Postei boundstone

Stromatoporoidal boundstone, patch reef 129 Bolintin

280 Videle

Coral bounds tone, patch reef

1056 Blejesti 196 Videle

Algal wackestone, patch reef 0,01 cm

1056 Blejesti

1454 Epuresti Algal-intraclastic grainstone

0,01 cm

Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs name 18 Presentation 591 Balaria

0,01 cm

2. Defining of Lower Cretaceous carbonate depositional systems in order to predict reservoir properties - 2.5. Lower Cretaceous seismic - sequence stratigraphy

Seq3 Seq2

Seq1

? Legend Seq3 – seismic-stratigraphic sequence 3, second order depositional sequence?

Lower Cretaceous sequence stratigraphy of Central-Eastern Moesian Platform (modified after Haq, et al.).

Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs name 19 Presentation

3. Controls on carbonate reservoirs quality - 3.1. Reservoirs related to differentiated compaction on the outer/median ramp boundary or on the reef/shoal-bank flanks (Lucia, J. F. classification, 2003)

Vuggy pore types: • touching-vugs - fracture pore space

2233 Dumbrava, Valanginian

Dumbrava carbonate reservoirs Evolution of the Lower Cretaceous carbonate sequences andFractured depositional control on hydrocarbon reservoirsdue to differentiated compaction driven name 20 Presentation processes.

3. Controls on carbonate reservoirs quality - 3.1. Reservoirs related to differentiated compaction on the outer/median ramp boundary or on the reef/shoal-bank flanks

200 ms

293 m

Evolution of the Lower Cretaceous carbonate name sequences and depositional control on hydrocarbon reservoirs name Chapter 21 Presentation

3. Controls on carbonate reservoirs quality - 3.2. Reservoirs related to the karstic-fissure systems

Vuggy pore types: • touching-vugs - solution enlarged collapse fracture • separate vugs - moldic pores

Vuggy pore types: • touching-vugs - solution enlarged and partially filled cemented fractures

171 Udeni, Tithonian

2 Potigrafu, Tithonian

Tithonian karstic – fissure system development, Central-Eastern Moesian Platform.

1000 Videle, Barremian-Aptian

Karstic breccias, pore space filled with hydrocarbons Vuggy pore types: • touching-vugs - crackle mosaic texture

Vuggy pore types: • touching-vugs - cavernous pore space

(Lucia, J. F. classification, 2003)

589 Berceni, Barremian-Aptian

4237 Videle, Barremian-Aptian

Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs name 22 Presentation

Barremian-Aptian karstic – fissure system development, CentralEastern Moesian Platform.

3. Controls on carbonate reservoirs quality - 3.3. Reservoirs related to organic reef or microbial – algal activities (Lucia, J. F. classification, 2003) Vuggy pore types: • separate vugs - intrafossil pore space

Vuggy pore types:

Vuggyvugs pore types: • separate Vuggy pore types: intrafossil pore space • touching-vugs • touching-vugs - growth-framework pore space - growth-framework pore space

0,01 cm

• separate vugs - mold pore space

201 Corbii Mari, Barremian-Aptian Vuggy pore types: • touching-vugs - fenestral pore space

0,01 cm

60 Bragadiru, Berriadian-Valanginian 1056 Blejesti, Barremian-Aptian Vuggy pore types: • separate vugs - shelter pore space

280 Videle , Barremian-Aptian Vuggy pore types: • touching-vugs - growth-framework Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs name 23 Presentation 0,01 cm 1401 Gradinari, Valanginian pore space 253 Baldana, Berriasian-Valanginian

0,005 cm

3. Controls on carbonate reservoirs quality - 3.4. Reservoirs related to carbonate shoals/banks (oolitic, oncoidic, skeletal) or channels (rudstones, calcarenites)

Interparticle pore types: interparticle pore space - intergrain pore space Vuggy pore types: - touching-vugs - fracture pore space

Interparticle pore types: • interparticle pore space - intergrain pore space Vuggy pore types: • touching-vugs - fracture pore space Interparticle pore types: • interparticle pore space - intergrain pore space Vuggy pore types: • separate-vugs - mold pore space

221 Saftica, Barremian-Aptian

1712 Cartojani, Barremian-Aptian

1455 Epuresti, Barremian-Aptian

Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs name 24 Presentation (Lucia, J. F. classification, 2003)

3. Controls on carbonate reservoirs quality - 3.4. Reservoirs related to carbonate shoals/banks (oolitic, oncoidic, skeletal) or channels (rudstones, calcarenites) Interparticle pore types: • interparticle pore space - intergrain pore space

134 Corbii Mari, Berriasian-Valanginian

23 Vlasia, Berriasian-Valaanginian Interparticle pore types: • interparticle pore space - intergrain pore space 0,01 cm

Evolution of the Lower Cretaceous carbonate name sequences and depositional control on hydrocarbon reservoirs name Chapter 25 Presentation

3. Controls on carbonate reservoirs quality - 3.5. Reservoirs related to diagenetic processes (dolomitization, dissolutions)

Interparticle pore types: • interparticle pore space - intergrain pore space

Interparticle pore types: • interparticle pore space - intercrystal pore space

65 Frasinet, Berriasian-Valanginian

0,01 cm

129 Bolintin, Barremian-Aptian

(Lucia, J. F. classification, 2003) Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs name 26 Presentation

0,01 cm

• Favorable areas for hydrocarbon accumulations

Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs name 27 Presentation

Conclusions • Multidisciplinary data interpretation allowed the reconstruction of the regional evolution of the Lower Cretaceous carbonate ramp and the defining of depositional domains and characteristic facies. • The relationship between reservoir potential and ramp evolution resides in the combined effect of patch reef/shoal-bank distribution, depositional facies, karst-fissure system, differentiated compaction and diagenesis. • Most prolific Lower Cretaceous reservoirs are located in the median ramp, exhibiting patch reefs, shoals/banks or channels facies preserving their primary porosity. Secondary porosity was generated due to later tectonics, which triggered local developing of karst-fissure systems and extensive dissolutions. • Potential reservoirs are isolated patch reefs and shoals on the inner ramp which supported karstification and meteoric diagenesis. Other potential reservoirs are the interbedded reef or storm - derived debris, breccias, rudstones, calcarenites into the outer ramp, which underwent differentiated compaction.

• The obtained conceptual depositional model may be used as basis, norm or comparison for future reservoir modeling in the studied area.

Evolution of the Lower Cretaceous carbonate sequences and depositional control on hydrocarbon reservoirs name 28 Presentation