Hydrocarbon potential and prospects of NE Bulgaria and offshore Black sea an overview. Shale Gas Research Group

Transcription

1 Hydrocarbon potential and prospects of NE Bulgaria and offshore Black sea an overview Shale Gas Research Group Sofia, 26 January 2011

2 Outline Introduction Who we are? Major tectonic units and basins in Bulgaria and offshore Black sea Licensing activities for oil and gas in Bulgaria update October, 2010 Main areas of interest: - (I) Lower Paleozoic shales onshore NE Bulgaria (Blocks Novi Pazar, Silistra,Tzar Kaloyan); - (II) Tertiary rocks offshore Black Sea (Block Sveti Atanas) Summary

3 Shale Gas Research Group is oriented towards multidisciplinary expert e exploration and appraisal of gas shales in Bulgaria compilation of comprehensive databases from wells (Moesian Platform and Black Sea offshore) of the main source rocks in the Palaeozoic, Mesozoic and Cenozoic sedimentary successions, compiled from the huge existing sources on the lithostratigraphy, geophysical logs, age, thicknesses, depths, etc. assessment on the distribution of prospective shales related to the specific tectonic units and their basinal evolution and further orogenic phases, responsible for shale gas formation. maturity studies of the organic matter Vitrinite reflectance, Color Alteration Indices (CAI), Thermal Alteration Indices (TAI). Sofia University, Dept. of Geology, Paleontology and Fossil fuels Geological Instutute, Depts. of Regional Geology, Geotectonics, Paleontology, Stratigraphy and Sedimentology GEOLOGICAL B A S INSTITUTE Institute of Organic Chemistry, Laboratory Of Fuel Chemistry

4 Consulting in: Experience - Regional geology and geotectonics; - Stratigraphy, Sedimentology,, Depositional setting; - Biostratigraphy and correlation of all offshore wells in Bulgaria (since 1993). - Exploration and and development of conventional oil and gas fields. Texaco, British Gas, Enterprise Oil, OMW ( ), Melrose Resources, , 2010, Overgas Ink., 2007, Bulgarian Oil Company Neft & Gaz,, BOCL, Syria, Iraq, etc.

5 Study area

6 Regional Tectonic Setting (Main sources: Georgiev et al., 2001; Nikishin et al, 2001; Okay, Tuysuz, 1999)

7 Tectonic scheme of Bulgaria B A (After Dabovski, Georgiev 2005)

8 Eastern Bulgaria Tectonic cross-section A-B (After Georgiev, Dabovski, 2001, modified)

9 Stratigraphic chart Eastern Bulgaria (After Georgiev, Dabovski, 2001, modified)

10 Eastern Bulgaria Paleogeodynamic reconstruction (After Dabovski, Georgiev & Dimitrov, 2006)

11 Areas of interest Two main areas: Block Sveti Atanas (I) Onshore Lower Paleozoic rocks (Silurian-Devonian) in the blocks Novi Pazar, Silistra, Kubrat and Tzar Kaloyan (II) Offshore Tertiary rocks in block 22 (Sveti Atanas)

12 (I) Onshore Lower Paleozoic (Silurian-Devonian) in the blocks Novi Pazar, Silistra and Tzar Kaloyan Vetrino Mihalich

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14 NE Bulgaria Wells reaching the Lower Paleozoic

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20 Lithofacial evolution of the depositional setting during the Devonian Period NE Bulgaria

21 Lithofacial distribution map during Late Silurian-Early Devonian Deep shelf Shelf margin Carbonate platform

22 Lithofacial distribution map during Mid- Devonian

23 Block Tzar Kaloyan 2150 m 2240 m 1768 m

24 Lower Pz (Silurian and Lower Devonian) black shales cropping out at the surface (W Bulgaria) Svoge West Balkan Unit

25 The Saltar Formation (lydites, silicified shales and shales) includes over 40 m of graptolitic strata ranging in age from lowermost Rhuddanian to early Telychian, except for its first basal meter, which bears the last Ordovician graptolites.

26 Mala Reka Fm.: black shale succession rich in graptolites, 100 m thick.

27 Yabukov Dol Fm.: laminated shales, siltstones and black shales is m thick.

28 The upper part of the Pridolian (uppermost Silurian), as well as the Lochkovian and Pragian (Lower Devonian) represent a continous uniform black siltstone succession (Ogradishte Fm.), up to 300 m thick, dated on graptolites and tentaculites.

29 Areas of interest Block Sveti Atanas (II) (II) Offshore Tertiary rocks in block Sveti Atanas

30 Lower Kamchia sub-basin

31 STRUCTURAL PROFILE I-I Bourgas basin Balkanides M o e s I a n p l a t f o r m Kamchya basin Ushakov trough Tyulenovo trough (After Georgiev,, 2004)

32 Black Sea Offshore drilling operations experience in well site micropaleontology services since 1993 Texaco first commercial discovery Galata-1

33 Yury Shimanov Galata-1 R-79 Shkorpilovtsi Samotino More Samotino East Block Sveti Atanas

34 Biostratigraphy and chronostratigraphy Correlation of offshore wells

35 KAMCHYA BASIN Correlation of Well Sections Samotino More Samotino East Target source rocks: Avren + Ruslar Fms, claystones

36 Home Позициониране на платформата точност до 1 m Objective Qualifications Education Employment Skills

37 S Chronostratigraphic diagram of litostratigraphic units in Paleogene section across the S-N transect Emine Basin C Lower Kamchia basin R79 R R20 9 Moesian Platform R72 R Varn a N 11.2 Da2 Da1 Gebesh Atanas Emine Fm. - turbidites Illyrian u/c Dvoinitsa Group Kozichino Mb Meshilika. Bardarevo Uppe rbyal Footwa a ll uplift? Golitza Fault Obs or Lower Byala Onlap onto footwall of Golitza Fault (seismic) Mezdr a Avren Fm?u/c Aladan Fm.? Dikilitash Fm Komarevo Fm. Kailaka Fm Footwall uplift? Beloslav Fm Asparuhovo (slope in west) Dobrina / Kailaka Fault Bliznatzi

38 Source Rock Tertiary overview Good source potential through the Eocene and Lower Oligocene (Avren and Ruslar Formations = analogous to the Maykop Series in pre-caspian lowland) Overall considered gas prone although studies indicate the potential for oil generation at depth. TOC (Moesian Platform) = 0.99 to 4.62% (VW) TOC (Kamchia Depression) = maximum 2.3% (SM) On the Moesian Platform / Western Kamchia Depression = Thermogenically Immature but considered the source of biogenic gas accumulations Thick Tertiary section in the Kamchia Depression potential in deeper eastern extent. Detailed distribution requires further study.

39 Summary - Paleozoic prospect 1. Prospective source rocks Silurian-Lower Devonian Siltstone shale Formation 2. Distribution supposed to be widespread in blocks Novi Pazar, Tzar Kaloyan and Kubrat 3. Thickness hudge m (Michalich( Michalich) 2000 m (Vetrino( Vetrino) 4. TOC no available modern data, whereas but Radev (1987) reported 3.5% sapropel-organic organic matter. 5. Maturity - CAI ranging from 2,5 to 4,0 for Mid-Upper Devonian; TAI ranging from 2.0 to 5.0 in Vetrino, Michalich (Novi Pazar Block) 6. Depth to the targeted interval from the surface m in different parts of N Bulgarian uplift 7. Combined presence of source rocks Silty shale Fm.. and occurrence of reservoirs rocks in the overlain carbonates in the upper part of Devonian section permits to explore the blocks for prospective traps of conventional c oil and gas accumulations, as well as shale gas.

40 Summary - Tertiary prospect 1. Prospective source rocks Eocene and Oligocene claystones Avren and Ruslar Formations 2. Distribution vaste across whole area 3. Thickness varies between 1700 m (Samotino( More) and m (Galata-1) 4. TOC max reported 2.3% in Samotino More well; 5. Maturity - Western Kamchia Depression = Thermogenically Immature but considered the source of biogenic gas accumulations 6. Thick Tertiary section in the Kamchia Depression potential in deeper eastern extent.

41 Thank you for your attention!