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Geochemical

VIEWS: 1 PAGES: 26

									Labile S and Condensate Isotope




          Andrei Deev, Xinyu Xia and Yongchun Tang
          October 2010
Outline
   Comparison of Caspian Sea Oil cracking with and w/o TSR
   Generation of mercaptan (thiol)
   Carbon isotope of condensate with and w/o TSR
Caspian Sea Oil Cracking w/o TSR
   Experimental conditions
    –   Caspian oil
    –   30mg Talc
    –   30 mg Silica
    –   400 ul of 5.6% MgCl2 + 0.56% CaSO4 + 17% NaCl buffer
    –   360 C


    –   Non-TSR:        no more CaSO4
        TSR:            10 mg CaSO4
Hydrocarbon generation
          No obvious difference between methane and ethane
           yields

       30                                              12




                                                C2, ml/g
C1, ml/g




       20                                                  8
                                       TSR
       10                              NonTSR              4                       TSR
                                                                                   NonTSR
           0                                               0
               1   1.2           1.4   1.6                     1   1.2           1.4        1.6
                         Ro, %                                           Ro, %
Hydrocarbon generation
    Less yield of propane, n-butane and n-pentane yield in
     TSR
               12
                        TSR
    C3, ml/g




               8
                        NonTSR
               4

               0
                    1   1.2           1.4   1.6
                              Ro, %
Hydrocarbon generation
    Less yield of propane, n-butane and n-pentane yield in
     TSR
               12
                           TSR
                             5
    C3, ml/g




               8
                           NonTSR
                             4             TSR
                        nC4, ml/g



               4             3             NonTSR
                             2
               0
                             1
                    1       1.2
                             0         1.4        1.6
                                 Ro, %
                                1         1.2        1.4   1.6
                                               Ro, %
Hydrocarbon generation
    Less yield of propane, n-butane and n-pentane yield in
     TSR
               12
                           TSR
                             5
    C3, ml/g




               8
                           NonTSR
                             4            TSR
                        nC4, ml/g



               4             3             2
                                          NonTSR
                             2           1.5         TSR
                                     nC5, ml/g

               0
                             1                       NonTSR
                    1       1.2       1.4  1    1.6
                             0
                                 Ro, % 0.5
                                1        1.2       1.4      1.6
                                           0 Ro, %
                                                 1   1.2           1.4   1.6
                                                           Ro, %
Hydrocarbon generation
   Less yield of propane, n-butane and n-pentane yield in
    TSR: dryer gas in TSR


                     80
            Dryness, %



                     60
                     40          TSR
                     20          NonTSR
                         0
                             1   1.2           1.4   1.6
                                       Ro, %
Hydrocarbon generation
       Branched alkane yields even less in TSR

                8
                6
    iC4, ml/g




                        NonTSR
                4       TSR
                2
                0
                    1     1.2           1.4   1.6
                                Ro, %
Hydrocarbon generation
       Branched alkane yields even less in TSR

                8
                6
    iC4, ml/g




                        NonTSR
                4       TSR    4
                2                           3
                                iC5, ml/g


                                                          NonTSR
                0                           2             TSR
                    1     1.2               1       1.4     1.6
                                   Ro, %
                                            0
                                                1          1.2           1.4   1.6
                                                                 Ro, %
Hydrocarbon generation
               Branched alkane yields even less in TSR
                –    More obvious in isoalkane/n-alkane ratio


            1.5                                                    2.5
                           NonTSR
iC4/nC4, ml/g




                                                       iC5/nC5, ml/g
                           TSR                                       2
                 1
                                                                   1.5                     NonTSR
            0.5                                                      1                     TSR
                                                                   0.5
                 0                                                   0
                     1       1.2           1.4   1.6                     1   1.2           1.4      1.6
                                   Ro, %                                           Ro, %
Hydrocarbon generation
   Reason of changing in yield: stability of hydrocarbon in
    TSR
    methane > ethane >> other n-alkane >> iso-alkane
Non-hydrocarbon generation
           CO2 and H2S
                     TSR + Decomposition of Crude Oil



        200                                             200
                      TSR                                            TSR
                                                        150




                                                H2S, ml/g
        150
CO2, ml/g




                      NonTSR                                         NonTSR
        100                                             100
            50                                              50
             0                                               0
                 1    1.2           1.4   1.6                    1   1.2           1.4   1.6
                            Ro, %                                          Ro, %

                              Decomposition of Crude Oil
Non-hydrocarbon generation
   H2

                          H2 formation due to water-reforming

                10
                                NonTSR
                 8
         H2, ml/g




                                TSR
                 6
                 4
                 2
                 0
                      1          1.2           1.4     1.6
                                       Ro, %
                    H2 from water-reforming exhausted in TSR
Thiol (mercaptan) generation


                                           Decomposition of Crude Oil
              40                                                    0.4
CH3SH, ml/g




                                                     C2H5SH, ml/g
              30                                                    0.3       TSR
                                      TSR
              20                                                    0.2       NonTSR
                                      NonTSR
              10                                                    0.1

              0                                                      0
                                                                          1   1.2           1.4   1.6
                   1   1.2           1.4       1.6
                                                                                    Ro, %
                             Ro, %

                       Labile sulfur exhausted in TSR
Thiol Generation from H2S
   Problem:
    –   Thiol (mercaptan) as harmful compound in natural gas
    –   Its generation mechanisms unclear
   Purpose:
    –   Understanding the possibility and mechanism of thiol generation
        from H2S and hydrocarbon
Thiol Generation from H2S
   Experimental:
    –   Ethyl Benzene : Branched C8 : n-C8 = 1:1:1




    –   H2S 1.3 ml
    –   20 degC/h, 330 – 440 deg C
Results
   Hydrocarbon

                  4
                            C1
                  3
        Yield, ml/g



                            C2
                  2         C3
                  1

                  0
                      0.5    0.7    0.9    1.1   1.3
                                   Ro, %
Results
   Non-hydrocarbon
                                     H2 from water-reforming
                   5
                   4
                             CO2
         Yield, ml/g



                   3         H2
                   2
                   1
                   0
                       0.5    0.7    0.9     1.1      1.3
                                    Ro, %
Results
   Methanethiol has a beneficial maturity for generation, then
    converted to other compounds

                       0.4
         CH3SH, ml/g



                       0.3
                       0.2
                       0.1
                       0.0
                             0.5   0.7    0.9    1.1   1.3
                                         Ro, %
  Condensate Isotope Effected by TSR

        Isothermal Pyrolysis for Caspin Sea Oil


5 mg oil (Caspin Sea Oil) + 10 mg CaSO4 + 30mg Talc+30 mg Silica +400
microliters of 5.6%MgCl2+0.56%CaSO4+17%NaCl) buffer for TSR

5 mg oil + 30mg Talc+30 mg Silica +400 microliters of
(5.6%MgCl2+17%NaCl) buffer for non-TSR
  Thermal Alteration of Caspin Sea Oil, Ro = 1.3 With TSR




Thermal Alteration of Caspin Sea Oil, Ro = 1.3 Without TSR
                     TSR




Thermal Alteration
Summary
   Stability of alkanes in TSR:
    methane > ethane >> other n-alkane >> iso-alkane
    similar as cracking
   CO2 and H2S yield increases due to TSR
   Carbon isotope of toluene versus benzene shows different
    pattern between TSR and Non TSR thermal alteration
   H2 and thiols consumed in TSR
   Thiol generation observed from H2S and hydrocarbons

								
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