Jordan Milanov Jordanov Petroleum Geology and Petroleum Engineering Specialist

Transcription

1 Workshop: Socio-Economic Aspects of The Energy Corridor Linking The Caspian Region n with EU Baku, Azerbaijan: April 11 th 2007 ================================== HYDROCARBON POTENTIAL OF THE BULGARIAN BLACK SEA OFFSHORE Jordan Milanov Jordanov Petroleum Geology and Petroleum Engineering Specialist 1

2 Area of work 2

3 Tectonic scheme of Bulgarian Black Sea Offshore (After Bokov et al.,2002) 3

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6 Drilling Activity 23 Holes 6

7 Oil and Gas Fields 7

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9 Dolna Kamchia Depression (After Bokov et al.,2000) 9

10 Oil and Gas Resource Assessment Methodology 10

11 Purpose: Oil and gas localized recourse assessment... Implementation in: National policy and Regulatory activities Business investment strategy Municipalities Sustainable development 11

12 Why is it necessary?... Is there within the Bulgarian Black Sea Offshore billion tons of petroleum? 12

13 Oil and gas resources 13

14 At the moment.. More then 23 wells Only one discovery.. 14

15 Galata Kaliakra-99 Shabla Varna-Deep Emine Bourgas-Deep Licensed Blocks 15

16 Block Name Shabla Varna Deep Water Kaliakra 99 Galata Emine Bourgas Deep Water Area, km

17 ..three basic questions are to be answered: What is the probability (chance) of at least one conventional oil and gas field to present within the assessing (licensed) area How mach oil and gas present within the play outline (play fairway), expressed as field-number and field size distribution (probability volumetric curve) Haw much oil and gas present in individual prospect (prospect probability volumetric curve) 17

18 The answers are based on.. List of parameters, derived from petroleum play concept, processed with the probability analysis and techniques, implementing Monte Carlo simulations 18

19 Case study of a Petroleum play resources assessment Procedure's simplest model: Play's Hydrocarbon volume (in bbl) = Numbers of prospects X Success ratios (potential fields from all the prospects) X Potential field average size (in bbl) 19

20 Petroleum Play as an Element of a Petroleum System Economic Evaluation (Modeling) Risk Evaluation (play chance of exictance - the chance that there is at least one field of at least minimum size - 6 Mbbl) Potential field number distribution Number of prospects * Success ratio Monte Carlo Simulation Field size distribution derived from (i) Look-like play (ii) Representative prospects of a play (iii) Volumetric approach Risk related to regional geology - regional play chance Multiplication of the values assigned to the main play geological factors - for example (a * b * c * d). If there is at least one field of at least minimum size the play chance = 1 Risk related to the number of prospects whith the play if they are limited - reflects by success ratio value "Unrisked" potential curve of play hyrocarbon volumes (bbl) Average prospect chance = (a * b * c * d) * Success ratio "Risked" potential curve of play hyrocarbons volume (bbl) 20

21 Thrace basin Lower economic limit 10 bcf bcm Lower economic limit BULGARIAN BLACK SEA OFFSHORE Lower economic limit bcf or 0.40 bcm 21

22 Hamitabat 266 bcf Ayazli 350 bcf Doina gas 200 bcf Rescarus 12 MMto.e. Galata 125 bcf UPPER ECONOMIC VALUE BCF BCM 22

23 For Gaska 3.9 MMt Olimpijskaja compared to Lebada MMt 23

24 Rescarus 75 MMbbl 24

25 Some data concerning Success Ratios (SR) According to exploration statistics from the AAPG during SR for all USA = 0.16, increasing to 0.3 for some companies. Since 1978, the implementation of the new assessment techniques has led to SR near

26 Volume parameters Values 200 Frequency Distribution Area Mean 1690 sqkm 8.02 bcm Occurrences Hydrocarbon (in-place) Frequency Distribution R10% 2.0 bcm 50 R50% 6.0 bcm 0 0 2e+9 4e+9 6e+9 8e+9 1e e e e e+10 2e e e e e+10 3e e e e e+10 4e e e e e+10 R90% 16.0 bcm Volume 26

27 Frequency Distribution Volume parameters Area Mean Values 2601 sqkm 13.2 bcm Occurrences Hydrocarbon (in-place) Frequency Distribution R10% 3.0 bcm 50 R50% 10.0 bcm 0 0 5e+9 1e e+10 2e e+10 3e e+10 4e e+10 5e e+10 6e e+10 7e e+10 8e e+10 Volume R90% 26.0 bcm 27

28 Frequency Distribution Volume Values 400 parameters Area Mean 4495 sqkm 24.5 bcm Occurrences Hydrocarbon (in-place) Frequency Distribution R10% 6.0 bcm 100 R50% 18.0 bcm 0 0 1e+10 2e+10 3e+10 4e+10 5e+10 6e+10 7e+10 8e+10 9e+10 1e e e e e e e+11 Volume R90% 50.0 bcm 28

29 Shabla Block Volume parameters Area Mean R10% R50% R90% Values 2776 sqkm 13.0 bcm 3.2 bcm 9.7 bcm 26.4 bcm 29

30 Varna Deep Sea Block Volume parameters Area Mean Values sqkm 61.6 bcm R10% 15.1 bcm R50% 45.8 bcm R90% bcm 30

31 Bourgas Deep Sea Block Volume parameters Area Mean Values 7959 sqkm 37.4 bcm R10% 9.2 bcm R50% 27.8 bcm R90% 75.6 bcm 31

32 TOTAL RESOURCES bcm (10^9) Block Name Area R10 % R50 % R90 % Mean Galata Kaliakra Emine Shabla Varna Deep Bourgas Deep TOTAL

33 Area Resource Density Sea of Azov 9 MMcm/sqkm South Akcakoca Sub-basin basin represents acres 498 bcf (13.9 bcm) ) (High Case) 1.1 MMcm/sqkm Area Resource Density Bulgarian Black Sea Offshore MMcm/sqkm 33

34 South Akcakoca Sub-basin basin represents acres 498 bcf (13.9 bcm) ) High Case bcm/sqkm 1.1 MMcm/sqkm 34

35 Romanian resource growth rate (Discoveries timing) Cobalcesku Pescarus Data from Romanian Doina practice Portita Sinoe 1986 Lebada West Lebada East Discovery number Discovery year Data from Bulgarian practice First offshore drill activity 1983 R-1 R Nanevo First discovery 1993 First commercial gas production Time-span for total resource growth : Optimistic variant years.. Pessimistic variant years.. 35

36 What should be done Improve the the entire legislation in in order to to increase the the investment interest to to Bulgarian business climate Adoption of of such primary and and secondary rules that that will will stimulate operators to to plan plan and and spud wildcats Develop such an an approaches that that will will ensure drilling success and and reduce risk risk in in exploration ventures Development of of the the methodologies that that will will ensure more objectiveness in in resource assessment Finally. Money.. Money. Money. 36

37 My Teachers to whom are sent my Acknowledgements! 37

38 THANK YOU FOR YOUR ATTENTION! Jordan Milanov Jordanov,, PhD Petroleum Geology and Petroleum Engineering Specialist Expert Advisor Associate Professor Bulgarian National University of Mining and Geology Assembly St. Ivan Rilski, Sofia, Bulgaria Committee on Energy Geological Faculty Home: Office: 7 Anguelov vrah Sofia 1700 Sofia 1618; Bulgaria Studentski grad ( ) ;. ( ) /520) Mobile: +359 (0) JMJordanov@mgu.bg ;J.M.Jordanov@abv.bg 38

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40 Main Tectonic Units 40

41 Another Image 41

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43 Play types The success of the Ayazli-1 well validates our technological assessment that this shelf-edge play in the Black Sea offers outstanding 43

44 Field size High Case 266 bcf (7.5 bcm) 44

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54 Ayazli-1 Gas Discovery Well spudded 12th July 2004 Eocene reservoir targets at m tested gas at combined rate of 15mmscf/d 3D seismic indicates a number of satellite structures with reserve potential of 100 bcf Significant follow up potential on adjacent permits 1 TCF gross potential in area 54

55 The more prospective structures: Oligocene channela structure in the channel could hold more than 1 tcf recoverable, the company said. The planned exploration programme in Blocks Emine and Rezovska includes the acquisition of 3-D seismic data and a sea floor coring program. Both surveys will help reduce the exploration risk in the blocks; the former with improved subsurface definition and the latter with geochemical sampling for micro-seepage of migrating hydrocarbons. A large structural feature, the Ropotamo prospect, in Block Rezovska is a possible target for the 2006 drilling campaign. Interpretation of this prospect, which could contain reserves of up to 765 Bcf of gas or 330 MMbbl of oil, is being finalised and will determine if the prospect is ready for drilling. 55

56 Oil and gas fields, shows and seeps. Bottom effusions Most of the prospects exist due to structures formed by compression of the rocks in this region of the Black Sea. Encouraging results from satellite imagery have identified possible sea-floor oil seeps near the northern border of Rezovska close to many of the recognised prospects. This strongly suggests that generation and migration of hydrocarbons has taken place in the basin and therefore increases the likelihood that traps have been charged with hydrocarbons. Further evidence for the presence of hydrocarbons has come from seismic interpretation where bright amplitude anomalies have been identified at the crests of many structural closures. AVO modelling of seismic data is being carried out to try and determine whether or not these anomalies are direct indicators of trapped hydrocarbons.. 56

57 Risk recognition In the known gas accumulations the top seal is deltaic shales and claystones. Generally these seals are laterally extensive. Presence of an effective top seal is thus one of the lowest risks in the Thrace Basin. Little has been published on structural styles in this area, but the main trapping mechanisms in the Basin are dip closed anticlines. These structures are believed to be related to reactivation of deep seated faults associated with Basin readjustment, possibly focused along pinch-out edges of the underlying Hamitabat Sub-basin. It is likely, but is not documented, that some stratigraphic trapping also occurs in the Basin. 57

58 Upper cutoff value assignment - Pescarus 12 MMt o.e. The Ayazli-1 discovery supports Toreador's previous estimate of potential reserves in the South Akcakoca area of approximately 350 billion cubic feet of natural gas based on available information. Drilling costs for the Ayazli-1 well increased from the company's estimated $4.5 million to about $7.0 million due to inclement weather offshore, difficult drilling conditions in the formations below the gas-producing zones and a longer testing period than planned. Offshore Romania, a well will be drilled on the Midia Block to delineate the 1995 Doina gas discovery. The Geological Bezymyan structure and was prepared for geophysical deep drilling on work the lower Paleocene and carried middle out since the Eocene sediments by seismic surveys discovery well was in On Horizon IIIa at the top of the Paleogene drilled indicates this high is an anticline cut by that a fault the of northwest structure trend. On the closed could contain m structure contour this high approximately measures 6.5 by km and has a closure of 25 m. Its area is 14.6 sq km. billion cubic feet of Gas resources are assessed at 2.92 billion recoverable cu m (102 bcf). gas Only nine wells have been drilled in the Turkish sector of the Black Sea. A tenth was spudded in early May by Madison Oil Turkey Inc (parent Toreador Resources). Madison operates 14 coastal blocks, though its work is focused around its Ayazli-1 gas discovery and surrounding South Akcakoca sub-basin, where 13 potential drilling locations and six prospects have been identified 58 with reserve potential per prospect ranging from 100 Bcf to 1Tcf.