Petroleum Systems of East Africa: Hydrocarbon ... - Energy

Petroleum Systems of East Africa:Hydrocarbon Prospectivityof Kenya, Tanzania, and UgandaDaniel M. JarvieHumble Geochemical ServicesHumbleHumble (Houston), Texas, USAHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Humble, Texas (ca. 1905)Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Acknowledgements• Colleagues and Friends at• NOCK• PEPD• TPDC• ExxonMobil (hydrocarbon generation movie)• Stanford University (Mike Moldowan)• Colleagues at HumbleHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Talk Outline• Introduction to Petroleum Systems Analysis• Kenyan Petroleum Systems– Lokichar Basin– Anza Basin• Tanzanian Petroleum Systems– Songo Songo Condensate Inferences from GC analysis• Ugandan Petroleum System– typing of available seeps– rates of organic matter decomposition based on seepasphaltene kineticsHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Petroleum Systems AnalysisComponentsSource RockMigration RouteReservoir RockSeal RockTrapProcessesGenerationAdsorptionExpulsionMigrationAccumulationAlterationMixingIf any of these components or processes missing or improperly timed,no commercial hydrocarbon discovery can occur.Ref: Modified from Armentrout, 2001Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Triangle of SuccessGeochemistry(Hydrocarbon Charge)Geology(Framework)Geophysics(Trap)Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

East Africa:Petroleum SystemsKenya:Anza BasinSirius #1 wellLake Turkana AreaLoperot #1 wellUganda:Kibiro, Paara,and KibukoOil SeepsAlso Tanzania:Songo Songo Gas FieldCondensates(Coastal Basin – nonrift)Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Abu Gabra Formation (Aptian(Aptian-Albian), SudanREMAINING HYDROCARBON POTENTIAL (mg HC/g Rock)20181614121086420OrganicLeanAbu Gabra, SudanType I Oil Proneusu. lacustrine0 1 2 3 4 5TOTAL ORGANIC CARBON (TOC, wt.%)TYPE II Oil Prone(usu. marine)Mixed Type II / IIIOil / Gas ProneType IIIGas ProneDryGas ProneHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Poi Formation, Loperot #1 well, Lokichar Basin, Kenyaand Abu Gabra Formation, SudanREMAINING HYDROCARBON POTENTIAL (mg HC/g Rock)20181614121086420OrganicLeanAbu Gabra, SudanLoperot #1Type I Oil Proneusu. lacustrine0 1 2 3 4 5TOTAL ORGANIC CARBON (TOC, wt.%)TYPE II Oil Prone(usu. marine)Mixed Type II / IIIOil / Gas ProneType IIIGas ProneDryGas ProneHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Correlation of Oils between Sudan and KenyaGCMS Abundance30000250002000015000100005000m/z 191: Tri-, tetra- and pentacyclic TerpanesC19tUnity Field OilSudanC20tC21tC23tC24tC25tC24TetC26tTsTmC29HC30HC31HGamaC33HC33HC34HC35HGCMS Abundance010000038 43 48 53 58 63 68 73 78Retention Time (min.)80000600004000020000m/z 191: Tri-, tetra- and pentacyclic TerpanesLoperot OilKenyaC19tC20tC21tC23tC24tC25tC24TetC26tTsTmC29HC30HC31HC33HC33HC34HC35H055 65 75 85 95 105 115 125Retention Time (min.)Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Correlation of Oils between Sudan and KenyaGCMS Abundance30000250002000015000100005000m/z 191: Tri-, tetra- and pentacyclic TerpanesC19tUnity Field OilSudanC20tC21tC23tC24tC25tC24TetC26tTsTmC29HC30HC31HGamaC33HC33HC34HC35HGCMS Abundance060000038 43 48 53 58 63 68 73 78Retention Time (min.)500000400000300000200000100000m/z 191: Tri-, tetra- and pentacyclic TerpanesSirius OilKenyaC19tC20tC21tC23tC24tC25tC24TetC26tTsTmC29HC30HC31HGamC33HC33HC34HC35H038 43 48 53 58 63 68 73 78Retention Time (min.)Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Geochemical Log of Loperot #1 Well, Lokichar BasinDepth (m) TOC S2 HI S2/S3 NOC Cal. %VRoDepth (m)TOCS2HI2 4 6 8 10 20 30 40 50 200 400 600 80020 40 60 80100 200 3001 2 31000S2/S3NOCCALVRO11001200130014001500160017001800190020002100Untested oil show???2200230024002500260027002800Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

1000Abu GabraFormation(Aptian-Albian)Sudan:KerogenTypeandMaturityHYDROGEN INDEX (mg OIL/g TOC)9008007006005004003002001000Type I(usu. lac.)Type II(usu. mar.)MixedType II - IIIType III(usu. terr.)Type IVOilWindowAbu Gabra, SudanCondensate –Wet GasWindowDry GasWindow0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20Calculated Vitrinite Reflectance Equivalent (Cal.VReq.)Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Abu GabraFormation(Aptian-Albian)SudanandPoi Member,Lokichar BasinKenyaHYDROGEN INDEX (mg OIL/g TOC)1000900800700600500400Type I(usu. lac.)Type II(usu. mar.)OilWindowAbu Gabra, SudanPoi Formation,KenyaKerogenTypeandMaturity3002001000MixedType II - IIIType III(usu. terr.)Type IVCondensate –Wet GasWindowDry GasWindow0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20Calculated Vitrinite Reflectance Equivalent (Cal.VReq.)Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

“Demonstration”of theVariabilityofLacustrinePetroleumSystems:Green RiverOil Shale,U.S.A.HYDROGEN INDEX (mg OIL/g TOC)1000900800700600500400300Type IOil Prone(usu. lacustrine)Type IIOil Prone(usu. marine)Mixed Type II / IIIOil / Gas Prone~0.55% RoKerogenTypeandMaturity2001000330 380 430 480 530 580Tmax ( o C)Ref: Jarvie et al., 2005Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Chevron Marsing #16ThermalMaturityAssessmentfromthincoallensesDepth (feet)0-120-240-360-480-600-720-840Vitrinite Reflectance - Depth PlotDepth = -4303 Log(Ro) + -2123, R² = 0.88-960MaturationProfile Immature-1080-12000.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 2.0Ro (%)Oil Zone Wet Gas Zone Dry Gas ZoneHumble Geochemical Services DivisionRef: Jarvie et al., 2005Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Comparison of Source Rocks: Sudan vs. Kenya• Abu Gabra, Sudan(n = 22)• Sharaf, Sudan(n = 15)• Poi Member, Kenya(n = 24)– Ave. TOC = 1.94– TOC Range• 1.15 – 3.49– Ave. HI = 403– HI Range• 128 – 542– Thickness = ~254 m.– Ave. TOC = 1.98– TOC Range• 1.34 to 2.68– Ave. HI = 429– HI Range• 299 – 543– Thickness = ~500 m.– Ave. TOC = 2.86%– TOC Range• 1.02 – 7.69%– Ave. HI = 508– HI Range• 186 – 748– Thickness = ~200 m.Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Generation VolumetricsAssumptions:1. Use average TOC values2. Use average HI values3. Assume 50% conversion4. Use reported thicknesses5. Assume 25 km2 area extentHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Generation Volumetricsusing prior assumptionsBarrels of Oil700,000,000.00600,000,000.00500,000,000.00400,000,000.00300,000,000.00200,000,000.00100,000,000.00-Poi Sharaf Abu GabraFormationHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Generation Volumetricsnormalized per unit of rockBarrels of Oil450,000,000.00400,000,000.00350,000,000.00300,000,000.00250,000,000.00200,000,000.00150,000,000.00100,000,000.0050,000,000.00-Poi Sharaf Abu GabraFormationHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Abu Gabra Formation (Aptian(Aptian-Albian), SudanASSESSMENT OF INFERRED SOURCE ROCK LITHOFACIESbased on Gas Chromatographic Analyses of OilsDIBENZOTHIOPHENE-to-PHENANTHRENE RATIO5.04.54.03.53.02.52.01.51.00.5ZONE 1B ZONE 1AUnity Field Oil, SudanLoperot #1 DST oil, KenyaSirius #1 DST oil, KenyaZONE 2 ZONE 3 ZONE 4ZONE 1A MARINE CARBONATEZONE 1B MARINE CARBONATEMARINE MARLLACUSTRINE SULFATE-RICHZONE 2 LACUSTRINE SULFATE-POORMIXED SHALE/CARBONATEZONE 3 MARINE SHALE ANDOTHER LACUSTRINEZONE 4 FLUVIAL/DELTAIC0.00.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0PRISTANE-to-PHYTANE RATIOHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Abu Gabra Formation (Aptian(Aptian-Albian), SudanGAS CHROMATOGRAPHY DATAINFERRED SOURCE ROCK KEROGEN TYPE AND DEPOSITIONAL ENVIRONMENTPristane / nC17(Log Scale)1051.00.50.10.05Unity Field Oil, SudanLoperot #1 DST oil, KenyaSirius #1 DST oil, KenyaIncreasing thermal maturityOxidizingReducingType II (low S, marine shales)Type III and humic coalsMixedType II (marls)Type II (high S, carbonates)Some Type I0.010.01 0.05 0.1 0.5 1.0 5 10Phytane / nC18(Log Scale)Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Basin Modeling: Prospect SiteThe Shell Loperot-1well was a shallowwell drilled as astratigraphic test. Aprospect site #1 atSP 340 showshigher possibilityfor hydrocarbonsfrom the thicklacustrine sourcerocks identified inthe Loperot-1 well.Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

“Lobster” ProspectLokichar BasinKenyaHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Anza Basin:Sirius #1 well• Prospective source rocks– 5 thin oil prone source rocks were penetrated inthe Cretaceous section– thickness ranged from 3-10 m• TOC values range from 3 - 9% TOC– source rock could be the Aptian-Albian shaleslying on the flanks of the high tested by theSirius-1 well (Morley, 1999)• Waxy RFT oil recoveredHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

01 0002 0003 0004 0005 0006 0007 0008 0009 0001 000001 0002 0003 0004 0005 0006 0007 0008 0009 0001 000001 0002 0003 0004 0005 0006 0007 0008 0009 0001 000001 0002 0003 0004 0005 0006 0007 0008 0009 0001 000001 0002 0003 0004 0005 0006 0007 0008 0009 0001 0000Anza Basin: Sirius #1 LogORGANIC RICHNESS010002000OrganicRichHYDROCARBONPOTENTIALExcellentOIL or GAS PRONEORGANIC MATTERGas MixOil(mar.)Oil(lac.)Low maturity or expelledEarly mature source rockNORMALIZED OILCONTENTMature stained source rockOil/Gas Production or ContaminationImmatureCALCULATED MATURITYOil ZoneCondensate ZoneDry Gas ZoneImmatureOil ZoneCondensate ZoneMEASUREDMATURITYDry Gas Zone30004000DEPTH (feet)50006000700080009000100000 1 2 3 4TOC (wt.%)0 5 10 15 20OIL POTENTIAL (S2)0 200 400 600 800 1000HYDROGEN INDEX (HI)0 50 100 150 200NORMALIZED OIL CONTENT0.2 1.2 2.2 3.2 4.2CALCULATED %Ro0.2 1.2 2.2 3.2 4.2VITRNITE REFLECTANCEHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Sirius #1 Oil: High Resolution GCMSMS(414.4 231.2 transition) C 30 4-methyl-steranesSample 610 Ion mass 414.400->231.200100000DST oilLacustrineIndicators:80000600004000020000• Recovered in formationfluid from a reverse outof test interval 1517-1520 m.• Very waxy• High pour point: 49 o C67.29167.53767.90668.86569.28369.52969.996S302MaaaSS303MaaaSS302MabbSS302MabbRS303MabbRS303MabbSS304MaaaSS304MabbR S304MabbS_2MaaaRS303MaaaRDS4aSS20RDS4aSR20RS304MaaaRDS4aRR20RDS4aRS20R75.158• High C30 4-Me-steranes• Low C30regular steranes64 66 68 70 72 74 76Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

TanzaniaCoastal Basin(non-rift basin):SongoSongoDry GasWells--------CondensatesamplesHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Inferred Depositional Environment of SourceRock from Songo Songo CondensatesGAS CHROMATOGRAPHY DATAINFERRED SOURCE ROCK KEROGEN TYPE AND DEPOSITIONAL ENVIRONMENTPristane / nC17(Log Scale)1051.00.5OxidizingGAS PRONEType III kerogenand humic coalsReducingMIXED OIL/GAS PRONEType II-III kerogenmixturesOIL PRONEType II kerogenalgal, marinestrongly reducing0.10.050.010.01 0.05 0.1 0.5 1.0 5 10Phytane / nC18(Log Scale)SONGO SONGO CONDENSATES (TANZANIA)Humble Geochemical Services DivisionHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

[METHYLCYCLOPENTANE]A ternary plot oflighthydrocarbons wasused by Jarvie (2001)to infer differentsource lithofaciesproviding elucidationof source facies.These data suggestan altered shalesource forthe Loperot-1oil.2.01.81.61.41.21.00.80.60.40.2Evidence for Fractionationpossibly by gas exsolutionVOLATILITY-SENSITIVE FRACTIONATION ASSESSMENTUSING C7 HYDROCARBONSFractionatedor AlteredSUM[cis+trans-1,3-DMCPs]Carbonate sources0.00.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0Clay-richshalesources 4.0TOLUENE-to-HEPTANE RATIO3.63.22.82.42.01.61.20.80.4LacustrineorOrdoviciansourcesC7 OIL TYPE, ALTERATION, AND MATURITY PLOTFractionation Pathway0.00.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0HEPTANE-to-METHYLCYCLOHEXANE RATIOSONGO SONGO CONDENSATES (TANZANIA)Humble Geochemical Services DivisionSONGO SONGO CONDENSATES (TANZANIA)Humble Geochemical Services DivisionHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Songo Songo CondensatesInferred LithofaciesDIBENZOTHIOPHENE-to-PHENANTHRENE RATIO5.04.54.03.53.02.52.01.51.00.5ASSESSMENT OF INFERRED SOURCE ROCK LITHOFACIESbased on Gas Chromatographic Analyses of OilsZONE 1B ZONE 1AZONE 2 ZONE 3 ZONE 40.00.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0PRISTANE-to-PHYTANE RATIOSONGO SONGO CONDENSATES (TANZANIA)Humble Geochemical Services DivisionZONE 1A MARINE CARBONATEZONE 1B MARINE CARBONATEMARINE MARLLACUSTRINE SULFATE-RICHZONE 2 LACUSTRINE SULFATE-POORMIXED SHALE/CARBONATEZONE 3 MARINE SHALE ANDOTHER LACUSTRINEZONE 4 FLUVIAL/DELTAICThus, a marinesource is inferred.This is supportedby previousinferences ofMpanju and Philp(1994)andRego and Carr(2003)Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Gulf of Mexico Petroleum SystemsGulf of Mexico Petroleum SystemsWhich system(s) extendinto deepwater?Humble Geochemical Services Modified from Gross et al. (1995) 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

UgandanSeepSamplesHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Kibiro Seep: Asphaltene Kinetics100COMPUTED TRANSFORMATION RATIOAND VITRINITE REFLECTANCE (%Ro)USING A 3.3°C/million years CONSTANT HEATING RATEKINETICS DATA GRAPHICAL REPORT SUMMARY2.001.20COMPUTED GENERATION RATE CURVEAND VITRINITE REFLECTANCE (%Ro)USING A 3.3°C/million years CONSTANT HEATING RATE2.00TRANSFORMATION RATIO (%)9080706050403020101.801.601.401.201.000.800.600.40% RoGENERATION RATE1.000.800.600.400.201.801.601.401.201.000.800.600.40% Ro00.200 50 100 150 200TEMPERATURE (ºC)TRANS. RATIOCOMPUTED %Ro0.000.200 50 100 150 200TEMPERATURE (ºC)GEN. RATECOMPUTED %RoPERCENT OF REACTION3027242118151296DISTRIBUTION OF ACTIVATION ENERGIES3036 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80ACTIVATION ENERGY (kcal/mole)A = 1.0000E+14/secBULK KINETIC RESULTSSAMPLE:SAMPLE TYPE:BASIN:COUNTRY:MODEL:RESULTS (CURVE FITTING):HGS REF NO.:KIBIRO SEEPSEEP ASPHALTENEALBERTINE GRABENUGANDAGAUSSIANEXCELLENT960-25163-ASPHCALCULATED RESULTS USING 3.3ºC/million years MODEL:COMPUTED ONSET (10% TR) TEMPERATURE (ºC):COMPUTED ONSET (10% TR) %Ro VALUE:COMPUTED PEAK GENERATION TEMPERATURE (ºC):COMPUTED PEAK GENERATION %Ro VALUE:1350.801521.02Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Kibiro (Uganda), Loperot and Sirius Oils:Asphaltene Kinetics1.002.200.90UGANDAN OIL SEEPLOPEROT OIL ASPHALTENE2.00CALCULATED TRANSFORMATION RATIO0.800.700.600.500.400.300.20SIRIUS OIL ASPHALTENEVITRINITE REFLECTANCE1.801.601.401.201.000.800.60CALCULATED VITRINITE REFLECTANCE0.100.400.000 20 40 60 80 100 120 140 160 180 2000.20TEMPERATURE ( o C)Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Comparison of Ugandan Oil Seepto Loperot DST Oil (Kenya)Ugandan Oil Seep (m/z 191.2)320000Correlation showscomparable sourcefacies for bothKibiro seep andLoperot #1 DST oilYield ->24000016000080000020 30 40 50 60 70 80 90Time, minutes ->Loperot-1 Saturate GCMS (m/z 191.2)Both correlate toSudanese lacustrinesourced oilYield ->800006000040000C 30H20000C 23t060 70 80 90 100 110 120Time, minutes ->Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Recommendations for Sampling• Mud gas flow linesamples every 30 mplus any gas kicks,shows in Isotubes– for assessment of HCtype and maturity usinggas composition andcarbon isotopes• Bottled (IsoJar)cuttings samples alsofor measurement ofdesorbed gases and forwell preservedsamples for otherscreening and detailedanalysesC 30HC 23tHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

PredictedMaturityofBoonesvilleandBarnettShale GasesBoonesville gasesare expelled, oilassociatedBarnettShale generated gasRef: Jarvie et al., 2003δ 13 C Methane, Propane (ppt)Bacterial Methane70%60%50%40%30%20%10%Ro=0.50%δ 13 C Ethane (ppt)Boonesvillegases0.70%1.00%Barnettgases1.20%1.50%Methane vs. EthanePropane vs. Ethane2.00%3.00%-45.0 -40.0 -35.0 -30.0 -25.0 -20.0-70.0-65.0-60.0-55.0-50.0-45.0-40.0-35.0-30.0-25.0-20.0Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Future Work on Ugandan Seeps:Laboratory Maturation to Generate Normal Fingerprints90Sample h00-960-25163807060504030201020 40 60 80 100 120128000107000Yield86Yield600050004000420C1C3C5n-C7n-C9n-C11n-C13n-C15n-C17n-C18n-C19n-C21Paraffin Numbern-C23n-C25n-C27n-C29n-C31n-C33n-C35Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005300020001000C1C3C5n-C70Paraffin Numbern-C9n-C11n-C13n-C15n-C17n-C18n-C19n-C21n-C23n-C25n-C27n-C29n-C31n-C33n-C35

Conclusions: Principal Observations• There is strong geological and now geochemical evidencefor the Sudanese Lacustrine Petroleum System to extendinto Northern Kenya (Lokichar and Anza basins)• The source rock in the Lokichar Basin, Kenya is a potent asource rock as either the Abu Gabra or Sharaf source rocksin Sudan• Songo Songo condensate analysis suggest the likelihood ofa deeper oil pool and a marine source• The Ugandan oil seep is also lacustrine and decomposesover a narrow maturity windowHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Assistance to Students• Any students in Uganda, Tanzania, and Kenya arewelcome to contact Humble for geochemical analyses forresearch purposes or future presentationHumbleDavid Givens, former Humble student,geochemical technician, graduate U. ofNotre Dame, Super Bowl ChampionHumble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005

Thank youandpeace be with you !!Humble Geochemical Services 2 nd EAPC Entebbe, Uganda, March 2-4, 2005