The East African Petroleum Systems

Transcription

1 The East African Petroleum Systems CJ Matchette-Downes East Africa Exploration Limited www ea xcom Ref. K. Burke et al

2 Opening up of West Versus East Africa, Continental Margins The break up of Gondwana has had a fundamental control o on the make up and timing of source rock development in both the East and West break-up margins of the super- Continent Gondwana Ref. K. Burke et al

3 135mya Hauterivian Early Cretaceous 200mya Rhaetian Late Triassic Ref Reeves de Wit 165mya Bathonian Middle Jurassic

4 Tectonic Evolution Emphasis on East Africa India Separates from Madagascar Strike-Slip Trans-tension 90mya Turonian Late Cretaceous 135mya Hauterivian Early Cretaceous Ref Reeves de Wit 115mya Aptian Mid-Cretaceous

5 Tectonic Evolution Seychelles & India Separate 20mya - Miocene 90mya Turonian Late Cretaceous Ref Reeves de Wit 60mya - Palaeocene

6 Timing Early vs. late Style - Spreading Ridge vs. Passive margin Complexity -1 vs. 3 phases Data - More vs. less wells Result - easier oil vs. harder oil Ref GeoExpro 2007

7 AAPG Memoir 73) Petroleum Systems of South Atlantic Margins. Edited by Marcio Rocha Mello & Barry J Katz 1999 General Stratigraphy Modified from Rusk & Bertagne TGS NOPEC Morondava Road Show 2006

8 Upper Mesozoic vs. Lowermost Mesozoic, continental (lacustrine) oils East Africa: Several periods of failed rifting through Permo-Triassic Massive thickness of Karoo sediment Creation of unique rift basins / terrestrial source rocks Permian Sakoa coals, Madagascar Triassic Sakamena lacustrine source shales, Madagascar Reith Bank well in Seychelles penetrated Sakamena to Liassic age equivalent source rocks Extraordinarily low geothermal gradient

9 Geochemistry summary data available via GeoMark picture by Barry Rogers EAX Lacustrine oils are found in several localities throughout east & west Gondwana

10 Notional early Cretaceous restricted marine setting Notional early Mesozoic, restricted marine setting The Oil and gas habitats of the South Atlantic 1997, Edited by NR Cameron, RH Bate & S Clure 1999

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12 East Africa, Pemba # 5 oil extract δ 13 C saturates δ 13 C aromatics CV East Africa, Tundaua oil seep, Pemba Island δ 13 C saturates δ 13 C aromatics CV Jurassic, marine, carbonate dominated source i.e., the same source not Campanian, not Eocene Kiliwani North #1 flowed at 40 million SCF dry gas day -1 Jurassic, marine, carbonate dominated source Ref GeoMark Research Inc. O.I.LS. database

13 Local tar, Seychelles Cuttings extract Side Wall Core extract

14 Lead 24 Tilted (Karoo) Fault Block's) on new long offset seismic data, Seychelles the next basin north of ExxonMobil s Ambilobe basin & well 0km 5

15 Late cretaceous palaeo-atlantic geography fully marine East Africa: Fully marine settings persisted from mid Jurassic onwards AAPG Memoir 73 Petroleum Systems of South Atlantic Margins. Edited by Marcio Rocha Mello & Barry J Katz 1999

16 Note the large Tertiary Delta cones. Could East Africa s Ruvuma, Rufigi, Limpopo and other deltas generated/hold hydrocarbons?

17 Nigerian deltaic source and resultant crude Mnazi Bay oils highly mature condensates with an equivalent maturity y( (Rc%) of 1.3% corresponding well with the Lower Jurassic depth of burial confirmed by SCI ref Maputo 2008 The presence of Oleanane and Moretanes in an otherwise highly mature condensate is a result of solvent action as the migrated oil passes through the (immature) delta pile sands and shales.

18 The two Seychelles oil families There appears to be at least two source rock families as evidenced in the biomarker assemblages extracted from the tars. On the left the older Liassic/Upper Triassic family as seen in Coevity tars and AMOCO well source rocks an Upper Cretaceous / Tertiary source shares some affinities to the oils from 1. Lower C 29 Bombay High accumulation norhopane and (Ref O.I.L.S. database). Waxy Higher Plant (Bombay High a bit more resinous) Waxy Algal 1 significant, 2. Oleanane 2 NB high C 29, C 35 doublet and Gammacerane Two very different Sterane (M/z 217 distributions (nb scale differences) Lower Jurassic/Upper Triassic Upper Cretaceous/Tertiary Bombay High analogue

19 B d t i i t th E t Beyond a certain point the East African Petroleum Provence abruptly changes and oils from the Atlantic Provence are found.

20 Somalia Mandura Basin oil seeps/shows Ethiopia Hilala #3 Calub field Kenya Mandura Basin oil seeps and shows Tarbaj Hill Oil seep Pandangua #1: Oil shows Ria Kalui #1: Tarry bitumens (Triassic Maji-ya-Chumvi fish beds) Cities Services wells offshore Kenya: Oil shows Uganda The Great Lakes Albertine graben Tullow/Heritage 1 billion bbls Turaco, Paraa, Kibuku, Kibiro oil seeps & Kaiso-Tonya oil & gas seeps Tanzania Kiliwani North #1 40million SCF day -1 Makarawe: Tarry bitumens - Karroo age / Jurassic Tundaua: Oil seep - Jurassic (not Campanian) Pemba # 5: Oil shows Jurassic (same as as Pemba # 5) Kiwangwa: Tarry bitumens Jurassic? Zanzibar #1: Gas shows Mkuranga #1 Maurel et Prom 19.2 MSCFD thermogenic gas 5tcf Kimbiji East #1: Gas shows Tancan: Gas shows Mafia Island: Oil & gas shows Songo Songo: ca. 1+ tcf, Condensate in wells # 1,3,7,9. SS10 Okuza island: Oil shows - Jurassic Nyuni Island & well: Oil & gas shows - Jurassic Lipwapwatawre: Oil seep Mikandani: Oil seep Kisangire: Oil shows - Jurassic Wingayongo: Oil seep Jurassic Wingayongo #1 & #2-30m & 40m of tar sand Ruhoi River (5km from Wingayongo) - Oil seep Lukuliro: Gas shows - tars, sands in wells Mita Gamma: Oil shows Mandawa: Oil shows Mbuo: Oil shows Pindiro #1: Wet gas Lindi #1: Shallow gas blow out Manzi Bay #1 & 2: Gas reservoir, ~1 tcf+, Msimbati-1x (67MB equivalent) 28MMscfday -1 Mtwara # 1 Wet gas blowout Misimbati: Oil and gas seeps Mozambique Mocimboa # 1: Oil & gas shows Ponta Unifundo and Pemba seeps Inhaminga oil shows Buzi gas shows Pande & Termane, 1+ tcf Pipeline being expanded Inhassoro 2000bbls condensate Sunray wells: Oil shows Seychelles Reith Bank #1 oil shows & tar balls Seagull #1 shoals Madagascar Ankaramy #1 Oil shows & coastal bitumens Bemolanga Tar Sands 23B bbl in place Tsimiroro 2.2B bbl in place NW India Bombay High 3 Bbbls, multiple tcf Cambay basin 2.1 Bbbls, 1 tcf Pakistan

21 East African Exploration Permissions GeoMark Research - Analysis s TPDC, NOCK, INP, SEYPEC, Uganda & OMNIS Access to materials Gladestry Associates & GeoInsight East African terrains

22 The Continental Margin of Kenya, Tanzania, Mozambique, Madagascar and northernmost South Africa: Delivering i the understanding required to unlock new opportunities. JEBCO 2003 AAPG Memoir 73 Petroleum Systems of South Atlantic Margins. Edited by Marcio Rocha Mello & Barry J Katz 1999 The Oil and gas habitats of the South Atlantic 1997 Edited by NR Cameron, RH Bate & S Clure 1999 Africa's Petroleum Systems: From Outcrop to Deepwater. 6th PESGB / HGS African Conference, Cape Town 2007 Petroleum Geology of Africa, New themes and developing technologies Edited d by T Arthur, DS Macgregor & NR Cameron 2003 The Biomarker Guide Volume 2 Biomarkers & Isotopes in Petroleum Exploration & Earth History. KE Peters CC Walters JM Moldowan. Second edition 2005 O.I.L.S. database GeoMark Research