Assessment of Barnett Shale Petroleum Potential

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					                                                                                09


                               East African Rift
                              Petroleum Systems

                                      Daniel M. Jarvie
                                 Humble Geochemical Services
                              Division of Humble Instruments & Services, Inc.




Humble Geochemical Services
                              Humble, Texas circa 1905

                                                                Humble
                                                               Salt Dome
                                                                  Field
                                                               discovered
                                                              about 1 year
                                                                  after
     Houston                                                   Spindletop
 Intercontinental
     Airport
   about 5 mins
       west


                Houston, Texas             Humble Oil & Refining Co.
               19 miles to south,                     =
               our largest suburb                ExxonMobil
Humble Geochemical Services
                                     Petroleum Geochemistry
                 • Exploration:                         • Production
                              –      High-grading         Assessing reservoirs and
                                  plays/prospects for       well plumbing
                                  likelihood of
                                  hydrocarbon charge
                                                          –   Reservoir continuity
          Source rocks        –                           –   Commingled allocation
          Oil typing          –                           –   EOR assessment
          Correlations        –                           –   Well plumbing
          Inversions          –
                      Exploration / Production:
Finding bypassed pay and predicting pre-test, pre-completion oil quality
Humble Geochemical Services
                              Petroleum System Definition:
                               Components and Processes

                               Components
          Source Rock                       Processes
Sometimes Migration Route                   Generation
  both    Reservoir Rock                    Migration          For gas
  Top     Seal Rock                         Accumulation     in fractured
                                                                shales
   &      Trap                              Preservation     must have oil
  Bottom                                                     destruction !
  needed
  If any of these components or processes missing or improperly timed,
          no commercial hydrocarbon discovery can occur.
Humble Geochemical Services
    East Africa
   Rift System:
Petroleum Systems
                 Kenya:
              Anza Basin
             Sirius #1 well
       Lake Turkana Area
         Loperot #1 well
               Uganda:
             Kibiro, Paara,
              and Kibuko
               Oil Seeps
       Tanzania:
 Songo Songo Gas Field
      Condensates


Humble Geochemical Services
                   Kenyan Basins: Petroleum Geology

               • Lokichar Basin
                              – sediments were likely deposited during the pre-rift to
                                early rift development of the Cretaceous Anza-Abu
                                Gabra rift-type graben which was crossed by the
                                younger (Late Cretaceous through to Recent) North
                                South trending Turkana Trough.
               • Anza Basin
                              – sediments were likely deposited within continental,
                                fluvial, and lacustrine environments, although marine
                                facies are occasionally present


Humble Geochemical Services
                               Loperot #1, Lodwar South Basin, Kenya
                                                     ORGANIC RICHNESS                                              HYDROCARBON                                           OIL or GAS PRONE                                                              NORMALIZED OIL                                                                 CALCULATED MATURITY
                                                                                                                     POTENTIAL                                           ORGANIC MATTER                                                                   CONTENT
                                                      0                                                    0                                                   0                                                          0
                                                                                                                                                                                                                                                                                                                           0




Geochemical                                                               Organic




                                                                                                                                                                                                                                                                                                                                Immature
                                                                                                                                                                                                                                                                                                                                           Oil Zone
                                                                                                                                                                                                                                                                                                                                                      Condensate Zone
                                                                                                                                                                                                                            Low maturity or expelled
                                                                                                                                                                                                                           Early mature source rock
                                                                                                                                                                                                                         M ature stained source rock
                                                                                                                              Excellent




                                                                                                                                                                                                                                                                Oil/Gas Production or Contamination
                                                                                                                                                                       Gas M ix    Oil       Oil                                                                                                                                                                        Dry Gas Zone
                                                                           Rich
                                                                                                                                                                                  (mar.)   (lac.)



  Log
                                                    500                                            5     0 0                                           5     0 0                                                   5     0 0
                                                                                                                                                                                                                                                                                                                    5    0 0




Upper interval
Excellent source
-High TOC                                          1000                                        1       0 0 0                                       1       0 0 0                                               1       0 0 0
                                                                                                                                                                                                                                                                                                                1       0 0 0




-Oil Prone
-Oil shows
                                  DEPTH (meters)




-Early mature                                      1500                                    1       5     0 0                                   1       5     0 0                                           1       5     0 0                                                                                1       5    0 0




-Thick
                                                   2000

Lower interval
                                                                                               2       0 0 0                                       2       0 0 0                                               2       0 0 0                                                                                    2       0 0 0




-Potential
 Reservoir?                                        2500                                    2       5     0 0                                   2       5     0 0                                           2       5     0 0                                                                                2       5    0 0




                                                   3000                                        3       0 0 0                                       3       0 0 0                                               3       0 0 0                                                                                    3       0 0 0




                                                          0.0       5.0             10.0                       0     20          40       60                       0               500              1000                       0                         200              400                         600           0.2                               1.2               2.2     3.2    4.2
                                                                T OC (wt.%)                                        OIL POT ENT IAL (S2)                                   HYDROGEN INDEX (HI)                                            NORMALIZED OIL CONT ENT                                                                                          CALCULAT ED %Ro


 Humble Geochemical Services
                              Loperot #1, Lodwar South Basin, Kenya
     Espitalie Kerogen Type                                                        1000
                                                                                                                                   ~0.60% Ro




       and Maturity Plot                                                            900
                                                                                                                  Type I
                                                                                                                 Oil Prone
                                                                                                                                                   Lacustrine
                                                                                                                                                   Source Rocks
  This plot shows the variability in                                                800



  hydrogen indices in the POI member.                                               700

  While seldom seen in the literature                                                                                                               Low Tmax




                                                 HYDROGEN INDEX (m g O IL/g TOC)
  lacustrine source rocks have quite                                                600
                                                                                                   Type II (usu. marine)                            values mean
  variable Hydrogen Indices (e.g., Green                                            500
                                                                                                        Oil Prone
                                                                                                                                                    oil staining
  River oil shale ranges from 50-900).
  The uniform Tmax values are also                                                  400
                                                                                                                                                         High Tmax
  typical of lacustrine source rocks.                                               300
                                                                                                                                                         values below
                                                                                                                                                         2450 m.
                                                                                                   M ixed Type II / III


  Below 2450 m. the samples have much
                                                                                                   Oil / Gas Prone


                                                                                    200
  higher Tmax values (ca. 1.10%Roe).                                                                    Type III
                                                                                                       Gas Prone

                                                                                    100

  Samples with very low Tmax values                                                                                                                  ~01.40% Ro
                                                                                                Type IV: Dry Gas Prone

  are oil stained and not indicative of                                               0
                                                                                          330               380              430                   480            530   580

  thermal maturity.                                                                                                                            o
                                                                                                                                       Tmax ( C)




Humble Geochemical Services
                                             Similar Petroleum System:
                                            Green River oil shale,U.S.A.
                         Marginal Lacustrine                                                                                             404.1               3.57               2.61         25.91    0.9   434   726
                         Nearshore Open Lacustrine   Sand                                                                               699.6                0.68               0.14          0.62   0.43   432    91
                         Nearshore Open Lacustrine   Carbonate                                                                           703.4               2.57               0.42           15    0.54   437   584
                         Marginal Lacustrine         Carbonate Mud Flat                                                                 1043.5               3.84               1.69         28.89   0.86   435   752
                         Marginal Lacustrine         Carbonate Mud Flat                                                                 1064.2               8.06               2.41         74.58   0.83   436   925
                         Marginal Lacustrine         Distal Deltaic                                                                     1185.4               2.97               0.43          9.06   0.49   435   305
                         Marginal Lacustrine         Deltaic                                                                            1225.1               0.09               0.06          0.21   0.15   399   233
                                                                                         1000
                                                                                                                                           ~0.60% Ro




                                                                                          900
                                                                                                                             Type I
                                                                                                                            Oil Prone


                                                                                          800




                                                                                          700
                                                         HYDROGEN INDEX (mg OIL/g TOC)




                                                                                          600


                                                                                                        Type II (usu. marine)
                                                                                                             Oil Prone
                                                                                          500




                                                                                          400




                                                                                          300
                                                                                                      Mixed Type II / III
                                                                                                      Oil / Gas Prone



                                                                                          200

                                                                                                         Type III
                                                                                                        Gas Prone

                                                                                          100
                                                                                                                                                             ~01.40% Ro
                                                                                                      Type IV: Dry Gas Prone

                                                                                            0
                                                                                                330                  380                 430               480            530          580
                                                                                                                                                       o
                                                                                                                                               Tmax ( C)


Humble Geochemical Services
                   Hydrocarbon Potential of
                Loperot Lacustrine Source Rocks

                              1200

                              1000

                              800

                              600
                                                          BO/AF
                              400

                              200

                                0
                                     Min.   Ave.   Max.


Humble Geochemical Services
                                                        Shell Loperot #1 DST oil
                                         250




                                                            n-C15
 Loperot #1                              200


 DST oil                                 150




                              Yield ->
 fingerprint                             100

 shows waxy                               50
 fingerprint, but
 with low                                  0
                                               0   20   40            60          80          100   120
 amounts of                                                    Time, minutes ->
 light hydro-                                               Shell Loperot #1 DST oil
 carbons typical                         18

 of low maturity
                                         15
 lacustrine
                              Yield ->




 source rocks:                           12




                                                                                       n-C7
                                          9


                                          6

 Pr/Ph = 1.68                                      4    8             12         16           20    24

                                                               Time, minutes ->
Humble Geochemical Services
              Loperot #1 Oil to Source Inferred Lithofacies

                                                                                ASSESSMENT OF INFERRED SOURCE ROCK LITHOFACIES
                                                                                    based on Gas Chromatographic Analyses of Oils
                                                                       5.0
                              DIBENZOTHIOPHENE-to-PHENANTHRENE RATIO



                                                                                                                             ZONE 1A MARINE CARBONATE
                                                                                                                             ZONE 1B MARINE CARBONATE
                                                                       4.5                                                           MARINE MARL
                                                                                  ZONE 1A                                            LACUSTRINE SULFATE-RICH
                                                                                                                             ZONE 2  LACUSTRINE SULFATE-POOR
                                                                       4.0                                                           MIXED SHALE/CARBONATE
                                                                                                                             ZONE 3   MARINE SHALE AND
                                                                       3.5                                                            OTHER LACUSTRINE
                                                                                                                             ZONE 4   FLUVIAL/DELTAIC

                                                                       3.0

                                                                       2.5
                                                                                  ZONE 1B




                                                                       2.0

                                                                       1.5

                                                                       1.0

                                                                       0.5      ZONE 2                  ZONE 3                          ZONE 4

                                                                       0.0
                                                                          0.0    0.5        1.0   1.5    2.0     2.5   3.0      3.5       4.0      4.5     5.0

                                                                                                    PRISTANE-to-PHYTANE RATIO




Humble Geochemical Services
                Comparison to Ugandan Oil Seep
                                                                Ugandan Oil Seep (m/z 191.2)

    Comparison of the                     320000


    Loperot-1 oil saturate                240000


    fraction biomarkers


                               Yield ->
                                          160000

    to those of Ugandan                    80000

    oil seep, shows                               0

    similar characteristics.                      20   30           40         50       60          70          80         90

                                                                         Time, minutes ->
                                                            Loperot-1 Saturate GCMS (m/z 191.2)




                                                                                                   C30H
                                          80000


                                          60000
                               Yield ->




                                          40000


                                          20000
                                                             C23t




                                             0

                                              60       70           80          90           100          110        120

                                                                         Time, minutes ->
Humble Geochemical Services
                          Basin Modeling: Prospect Site

   The Shell Loperot-1
   well was a shallow
   well drilled as a
   stratigraphic test. A
   prospect site #1 at
   SP 340 (see Fig. 4)
   shows higher
   possibility for
   hydrocarbons from
   the thick lacustrine
   source rocks
   identified in the
   Loperot-1 well.


Humble Geochemical Services
                                        Anza Basin:
                                     Comparison to Sudan
               • Extension of Sudan basins
                              – the Abu Gabra Basin of Sudan and the Anza Basin
                                were continuous rift basins from the Late Jurassic
                                through much of the Cretaceous
                              – the Chevron discoveries in Abu Gabra serve as
                                analogues for wells drilled in the northern Anza Basin
                              – the equivalent Neocomian to Lower Albian section,
                                which comprise the source and reservoir units of the
                                Unity and Helig fields of Sudan have not been
                                penetrated by wells drilled in Kenya


Humble Geochemical Services
                                                       Anza Basin: Sirius #1 Log
                                 ORGANIC RICHNESS                                 HYDROCARBON                                  OIL or GAS PRONE                                                                      NORMALIZED OIL                                                                                                   CALCULATED MATURITY                                                                                     MEASURED
                                                                                    POTENTIAL                                  ORGANIC MATTER                                                                           CONTENT                                                                                                                                                                                                               MATURITY
                                  0                                       0
                                                                                                                     0                                                  0
                                                                                                                                                                                                                                                                                                                           0
                                                                                                                                                                                                                                                                                                                                                                                                 0




                                                                                                                                                                                                                                                                                                                               Immature




                                                                                                                                                                                                                                                                                                                                                                                                     Immature
                                                                                                                                                                                                       Early mature source rock


                                                                                                                                                                                                                                       Mature stained source rock




                                                                                                                                                                                                                                                                                                                                                     Condensate Zone




                                                                                                                                                                                                                                                                                                                                                                                                                            Condensate Zone
                                                       Organic




                                                                                                                                                                            Low maturity or expelled




                                                                                                                                                                                                                                                                          Oil/Gas Production or Contamination




                                                                                                                                                                                                                                                                                                                                          Oil Zone




                                                                                                                                                                                                                                                                                                                                                                                                                Oil Zone
                                                                                               Excellent                     Gas Mix     Oil         Oil                                                                                                                                                                                                               Dry Gas Zone                                                             Dry Gas Zone
                                                        Rich                                                                            (mar.)     (lac.)




                               1000                                   1 000
                                                                                                                 1 000                                              1 000
                                                                                                                                                                                                                                                                                                                       1 000
                                                                                                                                                                                                                                                                                                                                                                                             1 000




                               2000                                   2 000
                                                                                                                 2 000                                              2 000
                                                                                                                                                                                                                                                                                                                       2 000
                                                                                                                                                                                                                                                                                                                                                                                             2 000




                               3000                                   3 000                                      3 000                                              3 000
                                                                                                                                                                                                                                                                                                                       3 000
                                                                                                                                                                                                                                                                                                                                                                                             3 000




                               4000                                   4 000
                                                                                                                 4 000                                              4 000
                                                                                                                                                                                                                                                                                                                       4 000
                                                                                                                                                                                                                                                                                                                                                                                             4 000
                DEPTH (feet)




                               5000                                   5 000
                                                                                                                 5 000                                              5 000
                                                                                                                                                                                                                                                                                                                       5 000
                                                                                                                                                                                                                                                                                                                                                                                             5 000




                               6000                                   6 000
                                                                                                                 6 000                                              6 000                                                                                                                                              6 000                                                                 6 000




                               7000                                   7 000
                                                                                                                 7 000                                              7 000                                                                                                                                              7 000                                                                 7 000




                               8000                                   8 000
                                                                                                                 8 000                                              8 000                                                                                                                                              8 000                                                                 8 000




                               9000                                   9 000                                      9 000                                              9 000                                                                                                                                              9 000                                                                 9 000




                               10000                                 1 0000                                     1 0000                                             1 0000                                                                                                                                             1 0000                                                                1 0000




                                       0   1       2        3    4            0   5       10         15    20            0     200     400   600    800     1000            0                                                     50                                100   150                                   200    0.2                           1.2                2.2     3.2   4.2     0.2                           1.2                  2.2     3.2   4.2
                                               TOC (wt.%)                         OIL POTENTIAL (S2)                            HYDROGEN INDEX (HI)                                                    NORMALIZED OIL CONTENT                                                                                                                                 CALCULATED %Ro                                               VITRNITE REFLECTANCE


Humble Geochemical Services
                        Sirius #1 Well: Kerogen Type and
                                    Maturity
                                                               1000
                                                                                                          ~0.60% Ro




                                                               900
                                                                                          Type I
                                                                                         Oil Prone


                                                               800




                                                               700
                               HYDROGEN INDEX (mg OIL/g TOC)




                                                               600



                                                                                Type II (usu. marine)
                                                                                     Oil Prone
                                                               500




                                                               400




                                                               300
                                                                              Mixed Type II / III
                                                                              Oil / Gas Prone



                                                               200
                                                                                     Type III
                                                                                    Gas Prone


                                                               100
                                                                                                                            ~01.40% Ro

                                                                            Type IV: Dry Gas Prone

                                                                  0
                                                                      330                 380           430               480            530   580
                                                                                                                      o
                                                                                                              Tmax ( C)
Humble Geochemical Services
                                    Compositional Kinetic Model:
                                                 Sirius #1 Source Interval (5300 ft.)



                                            GENERATION RATE                                                                                                                     KEROGEN TRANSFORMATION
                                                                      o                                                                                                                                o
                                     by fractional percentages at 3.3 C/my                                                                                                             by fraction at 3.3 C/my


                      1                                                                                                                                         100%
                                                                                                           *
                                                                           CORRECTED MACT10 PY/GC YIELDS




                     0.9                                                           3% 8%                                                                        90%




                                                                                                                                       KEROGEN TRANSFORMATION
                     0.8                                                                                       C1
                                                                                                               C2-C4                                            80%
                                                                     54%                                       C5-C14
                                                                                                35%
                                                                                                               C15+
   GENERATION RATE




                     0.7                                                                                                                                        70%
                                                                                                                              C15+                                                                                           C15
                     0.6                                                                                                                                        60%
                                                                                                                              C5-C14                                                                                         C5-C15
                     0.5                                                                                                      C2-C4                             50%                                                          C2-C4
                                                                                                                              C1                                                                                             C1
                     0.4                                                                                                                                        40%
                                                                                                                              TOTAL                                                                                          TOTAL
                     0.3                                                                                                                                        30%

                     0.2                                                                                                                                        20%

                     0.1                                                                                                                                        10%

                      0                                                                                                                                          0%
                           0   50   100          150           200                          250                         300                                            0   50   100          150           200   250   300
                                                           o                                                                                                                                           o
                                          TEMPERATURE ( C)                                                                                                                            TEMPERATURE ( C)




Humble Geochemical Services
                                           Anza Basin:
                                          Sirius #1 well

               • DST oil
                              – Recovered in formation fluid from a reverse out
                                of test interval 1517-1520 m.
                              – Dark brown tarry oil with moderate bright
                                yellow-white streaming cut
                              – Paraffinic
                              – Very waxy
                              – High pour point: 49oC

Humble Geochemical Services
                         Sirius DST 1517-1520 m. Oil Sample



                       900
                                                              700

                       800

                                                              600
                       700

                                                              500
                       600


                                                              400
                       500



                       400                                    300



                       300                                    200


                       200
                                                              100


                       100




                              20   40   60   80   100   120         46.90   47.60   48.30   49.00   49.70   50.40




Humble Geochemical Services
                                        Sudanese Oil Sample

                                                                     1400



                                                                     1200



                                                                     1000



                                                                     800



                                                                     600
                      2400

                                                                     400



                      2000                                           200




                      1600
                                                                                    5           10           15           20           25           30




                      1200




                       800
                                                                     1800




                                                                     1500
                       400


                                                                     1200




                                                                     900

                              20   40    60   80   100   120   140
                                                                     600




                                                                     300




                                                                            42.40       43.20        44.00        44.80        45.60        46.40        47.20




Humble Geochemical Services
                              High Resolution GCMSMS
                                          (414.4 231.2 transition)
                                            C30 4-methyl-steranes
                     Sample 610         Ion mass 414.400->231.200




                                                                                                      S304MaaaR
         100000                                                                                                                  Lacustrine
                                                                                                                                 Indicators:
           80000


                                                                                                                                 • High C30 4-

                                                                           S304MabbS_2MaaaR
           60000
                                                                                                                                   Me-steranes
                                                                            S303MaaaR
                                                                          S303MabbS




                                                                                                       DS4aRR20R
                                                                     S303MabbR
                                                                    S304MaaaS



                                                                                                                                 • Low C30
                                                                   S304MabbR
           40000



                                                                                                    DS4aRS20R
                                                                 S303MaaaS




                                                                                                 DS4aSS20R
                                                              S302MabbR




                                                                                                                                   regular steranes
                                                            S302MabbS




                                                                                              DS4aSR20R
                                                           S302MaaaS
                                                 69.283
                                      67.906




                                               69.529




           20000
                                               68.865
                                    67.537




                                                          69.996
                                   67.291




                                                                                                                   75.158




                      64      66         68               70                   72                         74                76



Humble Geochemical Services
                  Sirius #1 Terpane Biomarkers (191 m/z)



                    600000
                                                                           500000



                    500000
                                                                           400000


                    400000

                                                                           300000

                    300000


                                                                           200000

                    200000


                                                                           100000
                    100000




                              10   20   30   40   50   60   70   80   90            62   64   66   68   70   72   74   76




Humble Geochemical Services
                  Songo
                  Songo
                Condensate
                 sample




Humble Geochemical Services
                  Songo Songo Gas-Associated Condensates

                                               SONGO SONGO #5                             SONGO SONGO #5




                                                                        TOL
                                                                  MCH




                                                                              n-C17

                                                                                      n-C18
                        n-C6




                                          CH




                                                                               Pr
                                     BZ




                                                                                       Ph
                                                           n-C7
                               MCP




                                               SONGO SONGO #9
                                                                                          SONGO SONGO #9
                                                                        TOL
                                                                  MCH




                                                                              n-C17
                                          CH




                                                                                      n-C18
                                                                               Pr
                        n-C6




                               MCP




                                                           n-C7




                                                                                       Ph




Humble Geochemical Services
                  Inferred Depositional Environment of Source
                      Rock from Songo Songo Condensates

                                                  GAS CHROMATOGRAPHY DATA
                                INFERRED SOURCE ROCK KEROGEN TYPE AND DEPOSITIONAL ENVIRONMENT
                                                 10
                                                                                                                                NE en
                                                                                                                               O og als
                                                                                                                            PR ker co
                                                                                                                                                     NE
                                                   5                                                                     AS III ic                 O n
                                                                                                                       G pe um
                                                                                                                         y    h                P R ge
                                                                                                                        T d                 AS ro
                                                                                                                           an             /G ke
                                                                                                                                        IL II es
                                                                                                                                       O II-I tur
                                                                                                                                     ED pe ix




                                                                                                               O
                                                                                                                                   IX Ty m




                                                                                                                xi
                                                                                                                                 M                     E
                                                                                                                                                      N n




                                                                                                                  di
                                                                                                                                                    O og e e g




                                                                                                                    zi
                                                                                                                      ng
                                                                                                                                                PR ker rin cin
                                                                                                                                             IL         a u
                                                                                                                                            O e II l, m red
                                                 1.0                                                                                          p a
                                                                                                                                            Ty alg ngly
                              Pristane / nC17




                                                                                                                                                  ro
                                                                                                                                                st
                                (Log Scale)




                                                 0.5




                                                                                                                           Re
                                                                                                                            du
                                                                                                                              ci
                                                                                                                                ng
                                                 0.1


                                                0.05




                                                0.01
                                                    0.01   0.05   0.1                           0.5      1.0                                    5                10
                                                                             Phytane / nC18
                                                                              (Log Scale)

                                                           SONGO SONGO CONDENSATES (TANZANIA)
                                                                  Humble Geochemical Services Division




Humble Geochemical Services
                              Songo Songo Condensates
                                 Inferred Lithofacies
                                                                                 ASSESSMENT OF INFERRED SOURCE ROCK LITHOFACIES
                                                                                     based on Gas Chromatographic Analyses of Oils
                                                                       5.0
                              DIBENZOTHIOPHENE-to-PHENANTHRENE RATIO




                                                                                                                                                 ZONE 1A MARINE CARBONATE
                                                                                                                                                 ZONE 1B MARINE CARBONATE
                                                                       4.5                                                                               MARINE MARL
                                                                                                                                                         LACUSTRINE SULFATE-RICH
                                                                                  ZONE 1A

                                                                                                                                                 ZONE 2  LACUSTRINE SULFATE-POOR
                                                                       4.0                                                                               MIXED SHALE/CARBONATE
                                                                                                                                                 ZONE 3   MARINE SHALE AND
                                                                       3.5                                                                                OTHER LACUSTRINE
                                                                                                                                                 ZONE 4   FLUVIAL/DELTAIC

                                                                       3.0

                                                                       2.5
                                                                                  ZONE 1B




                                                                       2.0

                                                                       1.5

                                                                       1.0

                                                                       0.5      ZONE 2                      ZONE 3                                          ZONE 4

                                                                       0.0
                                                                          0.0    0.5        1.0     1.5        2.0          2.5          3.0        3.5       4.0      4.5     5.0

                                                                                                      PRISTANE-to-PHYTANE RATIO

                                                                                                  SONGO SONGO CONDENSATES (TANZANIA)
                                                                                                          Humble Geochemical Services Division




Humble Geochemical Services
                   A ternary plot of                          Evidence for Fractionation
                   light
                   hydrocarbons was
                   used by Jarvie (2001)
                                                              possibly by gas exsolution
                   to infer different
                   source lithofacies
                   providing elucidation
                   of source facies.                                                                                               Clay-rich
                                                              VOLATILITY-SENSITIVE FRACTIONATION ASSESSMENT
                                                                          USING C7 HYDROCARBONS
                                                                                                                                   shale                                         C7 OIL TYPE, ALTERATION, AND MATURITY PLOT

                                               2.0                                                                                 sources
                                                                                                                                       4.0

                   These data suggest          1.8                                                                                                              3.6



                   an altered shale            1.6                                                                                                              3.2




                                                                                                                                     TOLUENE-to-HEPTANE RATIO
                        [METHYLCYCLOPENTANE]




                                               1.4                                      Fractionated                                                            2.8


                   source for                  1.2
                                                                                         or Altered
                                                                                                                                                                2.4      Lacustrine
                                                                                                                                                                                 Fractionation Pathway
                                                                                                                                                                         or
                   the Loperot-1               1.0

                                               0.8
                                                                                                                                                                2.0

                                                                                                                                                                1.6      Ordovician
                   oil.                        0.6                                                                                                              1.2      sources
                                               0.4                                                                                                              0.8

                                               0.2                                                                                                              0.4

                                               0.0                                                                                                              0.0
                                                  0.0   0.1   0.2     0.3        0.4          0.5            Carbonate sources
                                                                                                           0.6  0.7 0.8  0.9 1.0                                   0.0     0.1    0.2      0.3        0.4          0.5          0.6     0.7   0.8   0.9   1.0

                                                                            SUM[cis+trans-1,3-DMCPs]                                                                                    HEPTANE-to-METHYLCYCLOHEXANE RATIO

                                                                    SONGO SONGO CONDENSATES (TANZANIA)                                                                                   SONGO SONGO CONDENSATES (TANZANIA)
                                                                            Humble Geochemical Services Division                                                                                 Humble Geochemical Services Division




Humble Geochemical Services
                     Ugandan
                      Seep
                     Samples
                       and
                     Waki #1:

                   Good source
                      rocks
                    identified
                   in Waki #1
Humble Geochemical Services
                    Ugandan Oil
                                                                                    Sample KIBUKU              Ion mass 191.20
                                                                           120000




                      Seeps
                                                                           100000




                                                                            80000




                                                                            60000




                                                                            40000




            Terpane biomarkers                                              20000




                                                                                                30        40          50        60        70




                              800000
                                       Sample KIBIRO                                         Sample PAARA

                                                                                    120000
                              700000



                              600000                                                100000



                              500000
                                                                                     80000

                              400000

                                                                                     60000
                              300000


                                                                                     40000
                              200000



                              100000                                                 20000



                                              30       40   50   60   70
                                                                                                     30          40        50        60        70




Humble Geochemical Services
                                               Conclusions

               • Lokichar Basin
                              – a thick (600 ft.) lacustrine source rock is present in the
                                Loperot-1 well, but is likely early oil window
                              – the petroleum potential of this lacustrine source rock is
                                enormous with a total oil potential of over 10 billion
                                barrels; at 10% efficiency this would suggest the
                                possibility of a billion barrel oil field
                              – other sites show high prospectivity for hydrocarbon
                                charge due to deeper burial of the lacustrine source
                              – trap size and seal are the largest risk factors



Humble Geochemical Services
                                            Conclusions

               • Anza Basin
                              – Amoco Sirius-1 well penetrated Cretaceous
                                section, which contained 5 relatively thin
                                prospective source rock sequences
                              – the presence of Lower Cretaceous age rocks
                                demonstrates the similarity to the rift basins of
                                Sudan
                              – the thermal maturity of the Cretaceous section
                                was peak oil window suggesting high potential
                                for oil generation and expulsion
                              – tentative correlation to northern Sudan oil
Humble Geochemical Services
                                              Conclusions

               • Ugandan oil seeps
                              – Paara and Kibiro are lacustrine
                              – Kibuku is uncertain possibly due to alteration (high
                                maturity, biodegradation)
                              – Kibiro seep shows correlation to Loperot #1 oil


               • Songo Songo Condensate
                              – has high MCH, toluene typical of terrestrial sourced
                                oils, but inferred lithofacies suggests a marine source
                              – may be a fractionated condensate from a deeper oil
                                system

Humble Geochemical Services

				
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posted:8/17/2011
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