Prospectivity of the Equatorial Conjugate Margins of Africa and South America

Transcription

1 Prospectivity of the Equatorial Conjugate Margins of Africa and South America Ron Borsato* 1, Jennifer Greenhalgh 1, Steve Wells 1, Rick Roberson 1, Carlos Fontes 2 1 PGS, 2 Geohub

2 Contents Introduction Regional Geology Existing Fields and Play Types African Equatorial Margin Prospectivity Cote d Ivoire Nigeria South American Equatorial Margin Prospectivity Brazilian offshore basins Conclusions

3 Prospectivity of the Equatorial Conjugate Margins INTRODUCTION

4 Introduction The transform margin is now established as a world class petroleum province A regional 2D and 3D database on the transform margin is utilised by PGS to gain an understanding of petroleum systems on a regional and local scale Data reveals undrilled potential for billions of barrels of resources, in a range of proven play types (relatively low risk!) This presentation will give a guided tour of both sides of the Equatorial transform margin, whilst focusing on specific basins

5 Atlantic Conjugate Margin Database BRAZIL 200,000 km² 3D 300,000 km 2D WEST AFRICA 180,000 km² 3D 35,000 km 2D

6 Prospectivity of the Equatorial Conjugate Margins REGIONAL GEOLOGY

7 Tectonic Evolution of the Equatorial Conjugate Margin SR1 INTRACRATONIC RIFTING Neocomian SR2 TRANSTENSIONAL RIFTING Aptian S1A WRENCH STAGE Albian S1B and MEGASEQUENCE 2 DRIFT STAGE WITH WRENCH REACTIVATIONS Upper Cretaceous to Recent Demerara Plateau DP St Paul Ilha de Santana Plateau IS Romanche Chain St Paul Romanche Chain Sources: NUPETRO, 2003 / Scotese Paleomap Project

8 Free Air Gravity from Satellite Atlantic Ocean The main Oceanic Fracture Zones are controlling the tectonic development on the Equatorial Margins Saint Paul F.Z. Romanche F.Z. Source: Modified from NUPETRO, 2003

9 Bouger Gravity from Satellite South American Margin CRUSTAL LIMIT SITUATED BETWEEN DARK BLUE AND LIGHT BLUE Source: Modified from NUPETRO, 2003

10 BRAZILIAN EQUATORIAL MARGIN CHRONOSTRATIGRAPHIC CHART CORRELATION

11 AFRICAN EQUATORIAL MARGIN CHRONOSTRATIGRAPHY AND PETROLEUM SYSTEMS Lion Panthere Belier Jubilee S S S Seme Aje S S Foxtrot S Espoir Tano S Hihon S Fifa

12 Chronostratigraphy & Schematic Cross-Section

13 After Tullow Post-Transform Turbidite Fan Play Fairway

14 After Tullow Jubilee Field - Ghana

15 Prospectivity of the Equatorial Conjugate Margins AFRICAN EQUATORIAL MARGIN

16 Prospectivity of the Equatorial Conjugate Margins COTE D IVOIRE

17 Free Air Gravity Extensive sediment pile on continental edge Precambrian granites Off-axis volcanic centres? Transform zones Syncline trends associated with St Paul fracture zone Romanche transform fault zone Significant basinal depocentres

18 Magnetics Precambrian NE-SW trend Banded iron fm? Extensions of Precambrian craton? Anticline zones associated with the termination of the St Paul F.Z. Transform basins created Two significant wrench transform elements visible one moving faster than other creates drag Volcanic centres? Synclinal structure associated with St Paul FZ? Iron formations responsible for magnetic high? Or just extremely thick crust?

19 Albian high and late Cretaceous drape SW NE Mid-Late Cretaceous shale seal Fan complex pinching out on Albian high Stratigraphic pinchouts Potential Flat Spot Syn-rift fault blocks Lower Aptian source

20 Baobab Field Cote d Ivoire Baobab Field Discovery year 2001 First Well Baobab-1x Oil in place 200 MMbbl Gas in place 40 BCF Age of reservoir Albian

21 San Pedro Well

22 Campanian/Maastrichtian Fan Top Fan TWT Polygon Size = 2520 km² TWT(s) 50 km

23 Fan Detail

24 Strike Line Through Anticline Zone

25 Prospectivity of the Equatorial Conjugate Margins NIGERIA

26 Nigeria Schematic Cross-Section

27 Structural Styles Shallow faulting with debris-induced slump and listric systems Extensional structural style with antithetic and synthetic systems

28 Syn and Post rift features Amplitude anomalies

29 Fifa Field - Nigeria Fifa Field Discovery year 2002 First Well Fifa-1 Oil in place non-commercial Gas in place non-commercial Age of reservoir Albian

30 Dip line through Aje and to new MC3D Aje Cenomanian Turonian Aje-1 Aje-2 Sea bed Major UC Major UC OML 113 MC3D Albian Nigeria Transform Margin MC3D

31 Late Cretaceous Fan 1 Strike line Preliminary amplitude extraction Dip line

32 Late Cretaceous Fan 2

33 Fan Systems

34 New NTM 3D Geostreamer Dataset!

35 Prospectivity of the Equatorial Conjugate Margins SOUTH AMERICAN EQUATORIAL MARGIN

36 BRAZILIAN EQUATORIAL MARGIN OFFSHORE BASINS.

37 Prospectivity of the Equatorial Conjugate Margins FOZ DO AMAZONAS BASIN

38 !!!!!!!!!!!!! FOZ DO AMAZONAS BASIN GEOHUB 2D Selected GEOHUB 2D Crustal Limit!!!!!! Sedimentary Basin Round Sectors 11 Exploration Blocks

39 FOZ DO AMAZONAS BASIN ARBITRARY 2D SEISMIC LINE /

40 FOZ DO AMAZONAS BASIN ARBITRARY 2D SEISMIC LINE / / /

41 FOZ DO AMAZONAS BASIN 2D SEISMIC LINE

42 FOZ DO AMAZONAS BASIN Tullow Oil announce Zaedyus 1 oil discovery in French Guiana. General Well Remarks Spud date March 5, The main objective is thought to be Cenomanian-Turonian, the Jubilee-play. The well is about 50km NW from the Brazilian offshore border. Sept. 9, Encountered 72 metres of net oil pay in two turbidite fans. Results of drilling, wireline logs and samples of reservoir fluids point to a good quality reservoir sands. Drilling operations will now continue and the well will be deepened to over 6,000 metres to calibrate the deeper geology. The well will then likely be sidetracked to enable cores to be obtained over the reservoir sections. Source: HIS September 2011

43 Prospectivity of the Equatorial Conjugate Margins CEARÁ BASIN

44 !!!!!!!!!!!!! CEARÁ BASIN GEOHUB 2D Selected GEOHUB 2D PGS 3D Selected PGS 3D Crustal Limit!!!!!! Sedimentary Basin Round Sectors 11 Exploration Blocks

45 CEARÁ BASIN 2D SEISMIC LINE

46 CEARÁ BASIN PGS 3D BM-CE-2 SURVEY IL 1700 IL 1700

47 New Discovery Ceara basin Few wells drilled off the shelf break

48 Prospectivity of the Equatorial Conjugate Margins POTIGUAR BASIN

49 !!!!!!!!!!!!! POTIGUAR BASIN GEOHUB 2D Selected GEOHUB 2D PGS 3D Selected PGS 3D Crustal Limit!!!!!! Sedimentary Basin Round Sectors 11 Exploration Blocks

50 POTIGUAR BASIN 2D SEISMIC LINE STRIKE

51 POTIGUAR BASIN PGS 3D BPOT100 SURVEY XL 5232 Survey 3D BPOT100, courtesy of PGS do Brasil XL 5232

52 POTIGUAR BASIN PGS 3D BPOT-100 SURVEY XL 7065 XL 7065

53 Prospectivity of the Equatorial Conjugate Margins CONCLUSIONS

54 Conclusions The Equatorial Transform Margin is a major petroleum province with significant remaining potential Both the Brazilian and African Conjugate Margins are still poorly explored interest is now beginning to accelerate The majority of Brazilian wells have been drilled on the platform area, and have oil and gas shows, including 8 small oil fields and subcommercial discoveries The primary challenge in the deep water will be to identify the presence of turbidite sands and long-distance migration pathways PGS s new extensive 2D and 3D datasets allow delineation of further prospects and geological reconstruction along both margins

55 Acknowledgements PGS colleagues and GeoHub associates NUPETRO Universidade Federal de Ouro Preto PGS Management