In situ thermal processing of a relatively permeable formation in a reducing environment
A method for treating a relatively permeable formation containing heavy hydrocarbons in situ may include providing heat from one or more heat sources to a portion of the formation. The heat may be allowed to transfer from the heat sources to a selected section of the formation. The transferred heat may pyrolyze at least some hydrocarbons within the selected section. A mixture of hydrocarbons may be produced from the selected section. In some embodiments, a reducing environment may be maintained in a portion of the formation.
1. A method of treating a relatively permeable formation containing heavy hydrocarbons in situ, comprising:
providing heat from two or more heaters to at least a section of the formation;
allowing the heat to transfer from two or more of the heaters to a part of the formation, wherein superposition of heat from at least two of the heaters pyrolyzes at least some hydrocarbons in the part of the formation;
providing H 2 to the formation to produce a reducing environment in at least some of the formation; and
producing a mixture from the formation.
2. The method of claim 1 , further comprising maintaining a temperature in the part of the formation in a pyrolysis temperature range of about 270° C. to about 400° C.
3. The method of claim 1 , further comprising separating a portion of hydrogen from the mixture and recirculating the portion into the formation.
4. The method of claim 1 , wherein at least one of the heaters comprises an electrical heater.
5. The method of claim 1 , wherein at least one of the heaters comprises a surface burner.
6. The method of claim 1 , wherein at least one of the heaters comprises a flameless distributed combustor.
7. The method of claim 1 , wherein at least one of the heaters comprises a natural distributed combustor.
8. The method of claim 1 , further comprising controlling a pressure and a temperature in at least a majority of the part of the formation, wherein the pressure is controlled as a function of temperature, or the temperature is controlled as a function of pressure.
9. The method of claim 1 , further comprising controlling the heat such that an average heating rate of the part of the formation is less than about 1° C. per day in a pyrolysis temperature range of about 270° C. to about 400° C.
10. The method of claim 1 , wherein providing heat from the two or more heaters to at least the section of the formation comprises:
heating a selected volume (V) of the relatively permeable formation containing heavy hydrocarbons from the two or more heaters, wherein the formation has an average heat capacity (C V ), and wherein the heating pyrolyzes at least some hydrocarbons in the selected volume of the formation; and
wherein heating energy/day (Pwr) provided to the selected volume is equal to or less than h*V*C V *ρ B , wherein ρ B is formation bulk density, and wherein an average heating rate (h) of the selected volume is about 10° C./day.
11. The method of claim 1 , wherein allowing the heat to transfer comprises transferring heat substantially by conduction.
12. The method of claim 1 , wherein the produced mixture comprises condensable hydrocarbons having an API gravity of at least about 25°.
13. The method of claim 1 , wherein the produced mixture comprises condensable hydrocarbons, and wherein about 0.1 % by weight to about 15 % by weight of the condensable hydrocarbons are olefins.
14. The method of claim 1 , wherein the produced mixture comprises non-condensable hydrocarbons, and wherein a molar ratio of ethene to ethane in the non-condensable hydrocarbons ranges from about 0.001 to about 0.15.
15. The method of claim 1 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 1 % by weight, when calculated on an atomic basis, of the condensable hydrocarbons is nitrogen.
16. The method of claim 1 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 1 % by weight, when calculated on an atomic basis, of the condensable hydrocarbons is oxygen.
17. The method of claim 1 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 5 % by weight, when calculated on an atomic basis, of the condensable hydrocarbons is sulfur.
18. The method of claim 1 , wherein the produced mixture comprises condensable hydrocarbons, and wherein greater than about 20 % by weight of the condensable hydrocarbons are aromatic compounds.
19. The method of claim 1 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 5 % by weight of the condensable hydrocarbons comprises multi-ring aromatics with more than two rings.
20. The method of claim 1 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 0.3 % by weight of the condensable hydrocarbons are asphaltenes.
21. The method of claim 1 , wherein the produced mixture comprises condensable hydrocarbons, and wherein about 5 % by weight to about 30 % by weight of the condensable hydrocarbons are cycloalkanes.
22. The method of claim 1 , wherein the produced mixture comprises a non-condensable component, wherein the non-condensable component comprises molecular hydrogen, wherein the molecular hydrogen is greater than about 10 % by volume of the non-condensable component at 25° C. and one atmosphere absolute pressure, and wherein the molecular hydrogen is less than about 80 % by volume of the non-condensable component at 25° C. and one atmosphere absolute pressure.
23. The method of claim 1 , wherein the produced mixture comprises ammonia, and wherein greater than about 0.05 % by weight of the produced mixture is ammonia.
24. The method of claim 1 , wherein the produced mixture comprises ammonia, and wherein the ammonia is used to produce fertilizer.
25. The method of claim 1 , further comprising controlling a pressure in at least a majority of the part of the formation, wherein the controlled pressure is at least about 2.0 bars absolute.
26. The method of claim 1 , further comprising controlling formation conditions to produce the mixture, wherein a partial pressure of H 2 in the mixture is greater than about 0.5 bars.
27. The method of claim 1 , wherein a partial pressure of H 2 in the mixture is measured when the mixture is at a production well.
28. The method of claim 1 , further comprising altering a pressure in the formation to inhibit production of hydrocarbons from the formation having carbon numbers greater than about 25.
29. The method of claim 1 , wherein providing hydrogen (H 2 ) to the formation further comprises:
hydrogenating hydrocarbons in the part of the formation; and
heating a portion of the part of the formation with heat from hydrogenation.
30. The method of claim 1 , further comprising:
producing hydrogen and condensable hydrocarbons from the formation; and
hydrogenating a portion of the produced condensable hydrocarbons with at least a portion of the produced hydrogen.
31. The method of claim 1 , wherein producing the mixture comprises producing the mixture in a production well, wherein at least about 7 heaters are disposed in the formation for each production well.
32. The method of claim 31 , wherein at least about 20 heaters are disposed in the formation for each production well.
33. The method of claim 1 , further comprising providing heat from three or more heaters to at least a portion of the formation, wherein three or more of the heaters are located in the formation in a unit of heaters, and wherein the unit of heaters comprises a triangular pattern.
34. The method of claim 1 , further comprising providing heat from three or more heaters to at least a portion of the formation, wherein three or more of the heaters are located in the formation in a unit of heaters, wherein the unit of heaters comprises a triangular pattern, and wherein a plurality of the units are repeated over an area of the formation to form a repetitive pattern of units.
35. A method of treating a relatively permeable formation containing heavy hydrocarbons in situ, comprising:
providing heat from two or more heaters to at least a section of the formation;
allowing the heat to transfer from two or more of the heaters to a part of the formation, wherein superposition of heat from at least two of the heaters pyrolyzes at least some hydrocarbons in the part of the formation;
wherein the part of the formation is heated in a reducing environment during at least some of the time that the part of the formation is being heated; and
producing a mixture from the formation.
36. The method of claim 35 , further comprising maintaining a temperature in the part of the formation in a pyrolysis temperature range of about 270° C. to about 400° C.
37. The method of claim 35 , wherein at least one of the heaters comprises an electrical heater.
38. The method of claim 35 , wherein at least one of the heaters comprises a surface burner.
39. The method of claim 35 , wherein at least one of the heaters comprises a flameless distributed combustor.
40. The method of claim 35 , wherein at least one of the heaters comprises a natural distributed combustor.
41. The method of claim 35 , further comprising controlling a pressure and a temperature in at least a majority of the part of the formation, wherein the pressure is controlled as a function of temperature, or the temperature is controlled as a function of pressure.
42. The method of claim 35 , further comprising controlling the heat such that an average heating rate of the part of the formation is less than about 1° C. per day in a pyrolysis temperature range of about 270° C. to about 400° C.
43. The method of claim 35 , wherein providing heat from the two or more heaters to at least the section of the formation comprises:
heating a selected volume (V) of the relatively permeable formation containing heavy hydrocarbons from the two or more heaters, wherein the formation has an average heat capacity (C V ), and wherein the heating pyrolyzes at least some hydrocarbons in the selected volume of the formation; and
wherein heating energy/day (Pwr) provided to the selected volume is equal to or less than h*V*C V *ρ B , wherein ρ B is formation bulk density, and wherein an average heating rate (h) of the selected volume is about 10° C./day.
44. The method of claim 35 , wherein allowing the heat to transfer comprises transferring heat substantially by conduction.
45. The method of claim 35 , wherein the produced mixture comprises condensable hydrocarbons having an API gravity of at least about 25°.
46. The method of claim 35 , wherein the produced mixture comprises condensable hydrocarbons, and wherein about 0.1 % by weight to about 15 % by weight of the condensable hydrocarbons are olefins.
47. The method of claim 35 , wherein the produced mixture comprises non-condensable hydrocarbons, and wherein a molar ratio of ethene to ethane in the non-condensable hydrocarbons ranges from about 0.001 to about 0.15.
48. The method of claim 35 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 1 % by weight, when calculated on an atomic basis, of the condensable hydrocarbons is nitrogen.
49. The method of claim 35 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 1 % by weight, when calculated on an atomic basis, of the condensable hydrocarbons is oxygen.
50. The method of claim 35 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 5 % by weight, when calculated on an atomic basis, of the condensable hydrocarbons is sulfur.
51. The method of claim 35 , wherein the produced mixture comprises condensable hydrocarbons, and wherein greater than about 20 % by weight of the condensable hydrocarbons are aromatic compounds.
52. The method of claim 35 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 5 % by weight of the condensable hydrocarbons comprises multi-ring aromatics with more than two rings.
53. The method of claim 35 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 0.3 % by weight of the condensable hydrocarbons are asphaltenes.
54. The method of claim 35 , wherein the produced mixture comprises condensable hydrocarbons, and wherein about 5 % by weight to about 30 % by weight of the condensable hydrocarbons are cycloalkanes.
55. The method of claim 35 , wherein the produced mixture comprises a non-condensable component, wherein the non-condensable component comprises molecular hydrogen, wherein the molecular hydrogen is greater than about 10 % by volume of the non-condensable component at 25° C. and one atmosphere absolute pressure, and wherein the molecular hydrogen is less than about 80 % by volume of the non-condensable component at 25° C. and one atmosphere absolute pressure.
56. The method of claim 35 , wherein the produced mixture comprises ammonia, and wherein greater than about 0.05 % by weight of the produced mixture is ammonia.
57. The method of claim 35 , wherein the produced mixture comprises ammonia, and wherein the ammonia is used to produce fertilizer.
58. The method of claim 35 , further comprising controlling a pressure in at least a majority of the part of the formation, wherein the controlled pressure is at least about 2.0 bars absolute.
59. The method of claim 35 , further comprising controlling formation conditions to produce the mixture, wherein a partial pressure of H 2 in the mixture is greater than about 0.5 bars.
60. The method of claim 59 , wherein the partial pressure of H 2 in the mixture is measured when the mixture is at a production well.
61. The method of claim 35 , further comprising altering a pressure in the formation to inhibit production of hydrocarbons from the formation having carbon numbers greater than about 25.
62. The method of claim 35 , further comprising controlling formation conditions by recirculating a portion of hydrogen from the mixture into the formation.
63. The method of claim 35 , further comprising:
providing hydrogen (H2) to the part of the formation to hydrogenate hydrocarbons in the part of the formation; and
heating a portion of the part of the formation with heat from hydrogenation.
64. The method of claim 35 , further comprising:
producing hydrogen and condensable hydrocarbons from the formation; and
hydrogenating a portion of the produced condensable hydrocarbons with at least a portion of the produced hydrogen.
65. The method of claim 35 , wherein producing the mixture comprises producing the mixture in a production well, wherein at least about 7 heaters are disposed in the formation for each production well.
66. The method of claim 65 , wherein at least about 20 heaters are disposed in the formation for each production well.
67. The method of claim 35 , further comprising providing heat from three or more heaters to at least a portion of the formation, wherein three or more of the heaters are located in the formation in a unit of heaters, and wherein the unit of heaters comprises a triangular pattern.
68. The method of claim 35 , further comprising providing heat from three or more heaters to at least a portion of the formation, wherein three or more of the heaters are located in the formation in a unit of heaters, wherein the unit of heaters comprises a triangular pattern, and wherein a plurality of the units are repeated over an area of the formation to form a repetitive pattern of units.
69. A method of treating a relatively permeable formation containing heavy hydrocarbons in situ, comprising:
providing heat from one or more heaters to at least a section of the formation;
allowing the heat to transfer from at least one of the heaters to a part of the formation;
controlling the heat such that an average heating rate of the part of the formation is less than about 1° C. per day in a pyrolysis temperature range of about 270° C. to about 400° C.;
providing H 2 to the formation to produce a reducing environment in at least some of the formation; and
producing a mixture from the formation.
70. The method of claim 69 , further comprising maintaining a temperature in the part of the formation in a pyrolysis temperature range of about 270° C. to about 400° C.
71. The method of claim 69 , further comprising separating a portion of hydrogen from the mixture and recirculating the portion into the formation.
72. The method of claim 69 , wherein at least one of the heaters comprises an electrical heater.
73. The method of claim 69 , further comprising controlling a pressure and a temperature in at least a majority of the part of the formation, wherein the pressure is controlled as a function of temperature, or the temperature is controlled as a function of pressure.
74. The method of claim 69 , wherein providing heat from the one or more heaters to at least the section of the formation comprises:
heating a selected volume (V) of the relatively permeable formation containing heavy hydrocarbons from the one or more heaters, wherein the formation has an average heat capacity (C V ), and wherein the heating pyrolyzes at least some hydrocarbons in the selected volume of the formation; and
wherein heating energy/day (Pwr) provided to the selected volume is equal to or less than h*V*CV*ρ B wherein ρ B is formation bulk density, and wherein an average heating rate (h) of the selected volume is about 10° C./day.
75. The method of claim 69 , wherein allowing the heat to transfer comprises transferring heat substantially by conduction.
76. The method of claim 69 , wherein the produced mixture comprises condensable hydrocarbons having an API gravity of at least about 25°.
77. The method of claim 69 , wherein the produced mixture comprises condensable hydrocarbons, and wherein about 0.1 % by weight to about 15 % by weight of the condensable hydrocarbons are olefins.
78. The method of claim 69 , wherein the produced mixture comprises non-condensable hydrocarbons, and wherein a molar ratio of ethene to ethane in the non-condensable hydrocarbons ranges from about 0.001 to about 0.15.
79. The method of claim 69 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 1 % by weight, when calculated on an atomic basis, of the condensable hydrocarbons is nitrogen.
80. The method of claim 69 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 1 % by weight, when calculated on an atomic basis, of the condensable hydrocarbons is oxygen.
81. The method of claim 69 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 5 % by weight, when calculated on an atomic basis, of the condensable hydrocarbons is sulfur.
82. The method of claim 69 , wherein the produced mixture comprises condensable hydrocarbons, and wherein greater than about 20 % by weight of the condensable hydrocarbons are aromatic compounds.
83. The method of claim 69 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 5 % by weight of the condensable hydrocarbons comprises multi-ring aromatics with more than two rings.
84. The method of claim 69 , wherein the produced mixture comprises condensable hydrocarbons, and wherein less than about 0.3 % by weight of the condensable hydrocarbons are asphaltenes.
85. The method of claim 69 , wherein the produced mixture comprises condensable hydrocarbons, and wherein about 5 % by weight to about 30 % by weight of the condensable hydrocarbons are cycloalkanes.
86. The method of claim 69 , wherein the produced mixture comprises a non-condensable component, wherein the non-condensable component comprises molecular hydrogen, wherein the molecular hydrogen is greater than about 10 % by volume of the non-condensable component at 25° C. and one atmosphere absolute pressure, and wherein the molecular hydrogen is less than about 80 % by volume of the non-condensable component at 25° C. and one atmosphere absolute pressure.
87. The method of claim 69 , wherein the produced mixture comprises ammonia, and wherein greater than about 0.05 % by weight of the produced mixture is ammonia.
88. The method of claim 69 , wherein the produced mixture comprises ammonia, and wherein the ammonia is used to produce fertilizer.
89. The method of claim 69 , further comprising controlling a pressure in at least a majority of the part of the formation, wherein the controlled pressure is at least about 2.0 bars absolute.
90. The method of claim 69 , further comprising controlling formation conditions to produce the mixture, wherein a partial pressure of H 2 in the mixture is greater than about 0.5 bars.
91. The method of claim 90 , wherein a partial pressure of H 2 in the mixture is measured when the mixture is at a production well.
92. The method of claim 69 , further comprising altering a pressure in the formation to inhibit production of hydrocarbons from the formation having carbon numbers greater than about 25.
93. The method of claim 69 , wherein providing hydrogen (H 2 ) to the formation further comprises:
hydrogenating hydrocarbons in the part of the formation; and
heating a portion of the part of the formation with heat from hydrogenation.
94. The method of claim 69 , further comprising:
producing hydrogen and condensable hydrocarbons from the formation; and
hydrogenating a portion of the produced condensable hydrocarbons with at least a portion of the produced hydrogen.
95. The method of claim 69 , wherein producing the mixture comprises producing the mixture in a production well, wherein at least about 7 heaters are disposed in the formation for each production well.
96. The method of claim 95 , wherein at least about 20 heaters are disposed in the formation for each production well.
97. The method of claim 69 , further comprising providing heat from three or more heaters to at least a portion of the formation, wherein three or more of the heaters are located in the formation in a unit of heaters, and wherein the unit of heaters comprises a triangular pattern.
98. The method of claim 69 , further comprising providing heat from three or more heaters to at least a portion of the formation, wherein three or more of the heaters are located in the formation in a unit of heaters, wherein the unit of heaters comprises a triangular pattern, and wherein a plurality of the units are repeated over an area of the formation to form a repetitive pattern of units.
99. A method of treating a relatively permeable formation containing heavy hydrocarbons in situ, comprising:
providing heat from one or more heaters to at least a section of the formation;
allowing the heat to transfer from at least one of the heaters to a part of the formation;
controlling the heat such that an average heating rate of the part of the formation is less than about 1° C. per day in a pyrolysis temperature range of about 270° C. to about 400° C.;
wherein the part of the formation is heated in a reducing environment during at least some of the time that the part of the formation is being heated; and
producing a mixture from the formation.
100. The method of claim 99 , further comprising maintaining a temperature in the part of the formation in a pyrolysis temperature range of about 270° C. to about 400° C.
101. The method of claim 99 , wherein at least one of the heaters comprises an electrical heater.
102. The method of claim 99 , further comprising controlling a pressure and a temperature in at least a majority of the part of the formation, wherein the pressure is controlled as a function of temperature, or the temperature is controlled as a function of pressure.
103. The method of claim 99 , wherein allowing the heat to transfer comprises transferring heat substantially by conduction.
104. The method of claim 99 , further comprising controlling a pressure in at least a majority of the part of the formation, wherein the controlled pressure is at least about 2.0 bars absolute.
105. The method of claim 99 , further comprising controlling formation conditions to produce the mixture, wherein a partial pressure of H 2 in the mixture is greater than about 0.5 bars.
106. The method of claim 105 , wherein the partial pressure of H 2 in the mixture is measured when the mixture is at a production well.
107. The method of claim 99 , further comprising controlling formation conditions by recirculating a portion of hydrogen from the mixture into the formation.
108. The method of claim 99 , further comprising:
providing hydrogen (H2) to the part of the formation to hydrogenate hydrocarbons in the part of the formation; and
heating a portion of the part of the formation with heat from hydrogenation.
109. The method of claim 99 , further comprising:
producing hydrogen and condensable hydrocarbons from the formation; and
hydrogenating a portion of the produced condensable hydrocarbons with at least a portion of the produced hydrogen.
110. The method of claim 99 , further comprising providing hydrogen (H 2 ) to at least a portion of the formation.