Enhanced hydrocarbon recovery from multiple wells by steam injection of oil sand formations

Abstract

The present invention is a method and apparatus for enhanced recovery of petroleum fluids from the subsurface by steam injection into highly permeable vertical inclusion planes in the oil sand formation, and heating the heavy oil and bitumen, which flow by gravity to the wells. The inclusion is propagated into a portion of the formation having a Skempton's B parameter of greater than 0.95 exp(−0.04 p′)+0.008 p′, where p′ is a mean effective stress in MPa at the depth of the inclusion. The inclusion planes can be propagated from only the central well, or from all wells, being the central well and the periphery wells. The inclusion planes are propagated into the formation to intersect and coalesce to provide hydraulic connection between the central well and the periphery wells. Steam is injected continuously in the central well, and liquids are produced continuously from all wells, whilst maintaining a liquid head over production tubing for steam trap control. By injection of solvents and other gases and controlling the reservoir temperature and pressure, a particular fraction of the in situ hydrocarbon reserve is extracted and water inflow into the heated zone is minimized.

1 . A method of improving production of hydrocarbon liquids from a subterranean formation of weakly cemented sediments, the method comprising the steps of:
 a) propagating a substantially vertical first inclusion by injecting a fluid filled with proppant particles into the formation in a first preferential direction having an azimuth from a substantially vertical central wellbore intersecting the formation;   b) after the viscosity of the injected fluid in the first inclusion has substantially reduced, propagating a substantially vertical second inclusion filled with proppant particles in the same but opposite preferential direction as the first inclusion initiated from a circumferential wellbore, the second vertical inclusion to intersect and coalesce with the first vertical inclusion in the same formation;   c) injecting steam into the central wellbore and into a process zone in the formation; and   d) producing heated hydrocarbon liquids up the wellbores.   
     
     
         2 . The method of  claim 1 , wherein the method includes propagating a plurality of first and second inclusions at varying azimuths and a plurality of circumferential wellbores at the same varying azimuths. 
     
     
         3 . The method of  claim 1 , wherein the method includes propagating a plurality of inclusions propagated from the wellbores at progressively shallower depths after the viscosity of the injected fluid in the immediate lower inclusion has reduced substantially, so that the shallower depth inclusions intersect and coalesce with the inclusions immediately beneath on their respective azimuths. 
     
     
         4 . The method of  claim 3 , wherein the method includes propagating a plurality of inclusions at varying azimuths and a plurality of circumferential wellbores at the same varying azimuths. 
     
     
         5 . The method of  claim 1 , wherein the proppant particles ranging in size from #4 to #100 U.S. mesh are sand, ceramic beads, resin coated sand and resin coated ceramic beads or mixture thereof. 
     
     
         6 . The method of  claim 1 , wherein the steam injection is a continuous injection, and the production of hydrocarbon liquids is also continuous. 
     
     
         7 . The method of  claim 1 , wherein the steam injection is a pressure pulsed cyclic injection or intermittent injection. 
     
     
         8 . The method of  claim 1 , wherein steam pressure in the process zone is at ambient reservoir pressure. 
     
     
         9 . The method of  claim 1 , wherein the method includes injecting into the process zone a non-condensing gas or a hydrocarbon solvent in a vaporized state or a mixture thereof. 
     
     
         10 . The method of  claim 9 , wherein the solvent is one of a group of ethane, propane, butane or a mixture thereof. 
     
     
         11 . The method of  claim 9 , wherein the solvent is mixed with a diluent gas. 
     
     
         12 . The method of  claim 11 , wherein the diluent gas is non-condensable under the process conditions. 
     
     
         13 . The method of  claim 12 , wherein the non-condensable diluent gas has a lower solubility in the hydrocarbon liquid than the saturated hydrocarbon solvent. 
     
     
         14 . The method of  claim 13 , wherein the diluent gas is one of a group of methane, nitrogen, carbon dioxide, natural gas or a mixture thereof. 
     
     
         15 . The method of  claim 1 , wherein the method includes injecting a hydrogenizing gas into the wellbore and thus into the fluids in the process zone to promote hydrogenation and thermal cracking reactions of at least a portion of the hydrocarbon fluids in the process zone. 
     
     
         16 . The method of  claim 15 , wherein the hydrogenising gas consists of one of the group of H2 and CO or a mixture thereof. 
     
     
         17 . The method of  claim 15 , wherein the method includes catalyzing the hydrogenation and thermal cracking reactions of at least a portion of the petroleum fluids in the process zone. 
     
     
         18 . The method of  claim 17 , wherein a metal-containing catalyst is used to catalyze said hydrogenation and thermal cracking reactions. 
     
     
         19 . The method of  claim 18 , wherein the catalyst is contained in a canister in tubing inside of the wellbore. 
     
     
         20 . The method of  claim 18 , wherein the proppant particles in the inclusions contain the catalyst for the hydrogenation and thermal cracking reactions. 
     
     
         21 . A method of improving production of hydrocarbon liquids from a subterranean formation of weakly cemented sediments, the method comprising the steps of:
 a) propagating a substantially vertical first inclusion by injecting a fluid filled with proppant particles into the formation in a first preferential direction at an azimuth from a substantially vertical central wellbore intersecting the formation;   b) propagating the substantially vertical first inclusion to intersect a circumferential relief wellbore operated at a reduced pressure and on azimuth with the propagating inclusion;   c) injecting steam into the central wellbore and into a process zone in the formation; and   d) producing the heated hydrocarbon liquids up the wellbores.   
     
     
         22 . The method of  claim 21 , wherein the method includes propagating a plurality of first inclusions at varying azimuths and a plurality of circumferential relief wellbores at the same varying azimuths. 
     
     
         23 . The method of  claim 21 , wherein the method includes propagating a plurality of inclusions propagated from the central wellbore at progressively shallower depths after the viscosity of the injected fluid in the immediately lower inclusion has substantially reduced, so that the shallower depth inclusions intersect and coalesce with the inclusions immediately beneath on their respective azimuths. 
     
     
         24 . The method of  claim 23 , wherein the method includes propagating a plurality of inclusions at varying azimuths and a plurality of circumferential relief wellbores at the same varying azimuths. 
     
     
         25 . The method of  claim 21 , wherein the proppant particles ranging in size from #4 to #100 U.S. mesh are sand, ceramic beads, resin coated sand and resin coated ceramic beads or mixture thereof. 
     
     
         26 . The method of  claim 21 , wherein the steam injection is a continuous injection, and the production of hydrocarbon liquids is also continuous. 
     
     
         27 . The method of  claim 21 , wherein the steam injection is a pressure pulsed cyclic injection or intermittent injection. 
     
     
         28 . The method of  claim 21 , wherein steam pressure in the process zone is at ambient reservoir pressure. 
     
     
         29 . The method of  claim 21 , wherein the method includes injecting into the process zone a non-condensing gas or a hydrocarbon solvent in a vaporized state or a mixture thereof. 
     
     
         30 . The method of  claim 29 , wherein the solvent is one of a group of ethane, propane, butane or a mixture thereof. 
     
     
         31 . The method of  claim 29 , wherein the solvent is mixed with a diluent gas. 
     
     
         32 . The method of  claim 31 , wherein the diluent gas is non-condensable under the process conditions. 
     
     
         33 . The method of  claim 32 , wherein the non-condensable diluent gas has a lower solubility in the hydrocarbon deposit liquid than the saturated hydrocarbon solvent. 
     
     
         34 . The method of  claim 33 , wherein the diluent gas is one of a group of methane, nitrogen, carbon dioxide, natural gas or a mixture thereof. 
     
     
         35 . The method of  claim 21 , wherein the method includes injecting a hydrogenizing gas into the wellbore and thus into the fluids in the process zone to promote hydrogenation and thermal cracking reactions of at least a portion of the petroleum fluids in the process zone. 
     
     
         36 . The method of  claim 35 , wherein the hydrogenising gas consists of one of the group of H2 and CO or a mixture thereof. 
     
     
         37 . The method of  claim 35 , wherein the method includes catalyzing the hydrogenation and thermal cracking of at least a portion of the petroleum fluids in the process zone. 
     
     
         38 . The method of  claim 37 , wherein a metal-containing catalyst is used to catalyze said hydrogenation and thermal cracking reactions. 
     
     
         39 . The method of  claim 38 , wherein the catalyst is contained in a canister in tubing inside of the wellbore. 
     
     
         40 . The method of  claim 38 , wherein the proppant particles in the inclusions contain the catalyst for the hydrogenation and thermal cracking reactions. 
     
     
         41 . The method of  claim 1 , wherein a portion of the formation in which the first inclusion is formed has a Skempton B parameter greater than 0.95 exp(−0.04 p′)+0.008 p′, where p′ is a mean effective stress in MPa at the depth of the first inclusion and the water saturation in the formation pores is greater or equal to 10%. 
     
     
         42 . The method of  claim 21 , wherein a portion of the formation in which the first inclusion is formed has a Skempton B parameter greater than 0.95 exp(−0.04 p′)+0.008 p′, where p′ is a mean effective stress in MPa at the depth of the first inclusion and the water saturation in the formation pores is greater or equal to 10%. 
     
     
         43 . A production well system for improving production of hydrocarbon liquids from a subterranean formation of weakly cemented sediments having an ambient reservoir pressure and temperature comprising:
 a) a substantially vertical central bore hole in the formation to a predetermined depth;   b) an injection casing grouted in the central bore hole depth to create a substantially vertical central wellbore, the injection casing being radially expandable by the introduction of a fluid;   c) a substantially vertical first inclusion created by injecting a fluid filled with proppant particles into the formation in a first preferential direction having an azimuth from the substantially vertical central wellbore intersecting the formation;   d) a substantially vertical circumferential bore hole in the formation to a predetermined depth;   e) an injection casing grouted in the circumferential bore hole depth to create a substantially vertical circumferential wellbore, the injection casing being radially expandable by the introduction of a fluid;   f) a substantially vertical second inclusion created by injecting the fluid filled with proppant particles from the circumferential wellbore, the second inclusion oriented in the same but opposite preferential direction as the first inclusion and oriented to intersect and coalesce with the first vertical inclusion in the same formation after the viscosity of the injected fluid in the first inclusion has substantially reduced, wherein the first inclusion and the second inclusion to form a process zone; and   g) means for injecting steam into the central wellbore and into the process zone in the formation, thereby producing heated hydrocarbon liquids up the wellbores.   
     
     
         44 . The production well system of  claim 43 , wherein the production well system includes a plurality of first and second inclusions at varying azimuths and a plurality of circumferential wellbores at the same varying azimuths. 
     
     
         45 . The production well system of  claim 43 , wherein the production well system includes a plurality of inclusions propagated from the central and circumferential wellbores at progressively shallower depths after the viscosity of the injected fluid in the immediate lower inclusion has reduced substantially, so that the shallower depth inclusions intersect and coalesce with the inclusions immediately beneath on their respective azimuths. 
     
     
         46 . The production well system of  claim 45 , wherein the production well system includes propagating a plurality of inclusions at varying azimuths and a plurality of circumferential wellbores at the same varying azimuths. 
     
     
         47 . The production well system of  claim 43 , wherein the proppant particles ranging in size from #4 to #100 U.S. mesh are sand, ceramic beads, resin coated sand, and resin coated ceramic beads or mixture thereof. 
     
     
         48 . The production well system of  claim 43 , wherein the means for injecting the steam injects the steam continuously, and the production of hydrocarbon liquids is also continuous. 
     
     
         49 . The production well system of  claim 43 , wherein the means for injecting the steam injects the steam intermittently as a pressure pulsed cycle. 
     
     
         50 . The production well system of  claim 43 , wherein steam pressure in the process zone is at ambient reservoir pressure. 
     
     
         51 . The production well system of  claim 43 , wherein the production well system includes means for injecting into the process zone a non-condensing gas, a hydrocarbon solvent in a vaporized state, or a mixture thereof. 
     
     
         52 . The production well system of  claim 51 , wherein the solvent is one of a group of ethane, propane, butane, or a mixture thereof. 
     
     
         53 . The production well system of  claim 51 , wherein the solvent is mixed with a diluent gas. 
     
     
         54 . The production well system of  claim 53 , wherein the diluent gas is non-condensable under the process conditions. 
     
     
         55 . The production well system of  claim 54 , wherein the non-condensable diluent gas has a lower solubility in the hydrocarbon liquid than the saturated hydrocarbon solvent. 
     
     
         56 . The production well system of  claim 55 , wherein the diluent gas is one of a group of methane, nitrogen, carbon dioxide, natural gas, or a mixture thereof. 
     
     
         57 . The production well system of  claim 43 , wherein the production well system includes means for injecting a hydrogenizing gas into the central wellbore and thus into the fluids in the process zone to promote hydrogenation and thermal cracking reactions of at least a portion of the hydrocarbon fluids in the process zone. 
     
     
         58 . The production well system of  claim 57 , wherein the hydrogenising gas consists of one of the group of H2 and CO or a mixture thereof. 
     
     
         59 . The production well system of  claim 57 , wherein the production well system includes means for catalyzing the hydrogenation and thermal cracking reactions of at least a portion of the petroleum fluids in the process zone. 
     
     
         60 . The production well system of  claim 59 , wherein a metal-containing catalyst is used to catalyze said hydrogenation and thermal cracking reactions. 
     
     
         61 . The production well system of  claim 60 , wherein the catalyst is contained in a canister in tubing inside of the central wellbore. 
     
     
         62 . The production well system of  claim 60 , wherein the proppant particles in the inclusions contain the catalyst for the hydrogenation and thermal cracking reactions. 
     
     
         63 . A production well system for improving production of hydrocarbon liquids from a subterranean formation of weakly cemented sediments having an ambient reservoir pressure and temperature comprising:
 a) a substantially vertical central bore hole in the formation to a predetermined depth;   b) an injection casing grouted in the central bore hole depth to create a substantially vertical central wellbore, the injection casing being radially expandable by the introduction of a fluid;   c) a substantially vertical circumferential relief bore hole in the formation to a predetermined depth;   d) an injection casing grouted in the circumferential relief bore hole depth to create a substantially vertical circumferential relief wellbore, the injection casing being radially expandable by the introduction of a fluid;   e) a substantially vertical first inclusion created by injecting a fluid filled with proppant particles into the formation in a first preferential direction at an azimuth from the substantially vertical central wellbore intersecting the formation, wherein the substantially vertical first inclusion intersects the circumferential relief wellbore operated at a reduced pressure and on azimuth with the first inclusion form a process zone; and   f) means for injecting steam into the central wellbore and into the process zone in the formation, thereby producing the heated hydrocarbon liquids up the wellbores.   
     
     
         64 . The production well system of  claim 63 , wherein the production well system includes a plurality of first inclusions at varying azimuths and a plurality of circumferential relief wellbores at the same varying azimuths. 
     
     
         65 . The production well system of  claim 63 , wherein the production well system includes a plurality of inclusions propagated from the central wellbore at progressively shallower depths after the viscosity of the injected fluid in the immediately lower inclusion has substantially reduced, so that the shallower depth inclusions intersect and coalesce with the inclusions immediately beneath on their respective azimuths. 
     
     
         66 . The production well system of  claim 65 , wherein the production well system includes propagating a plurality of inclusions at varying azimuths and a plurality of circumferential relief wellbores at the same varying azimuths. 
     
     
         67 . The production well system of  claim 63 , wherein the proppant particles ranging in size from #4 to #100 U.S. mesh are sand, ceramic beads, resin coated sand, and resin coated ceramic beads or mixture thereof. 
     
     
         68 . The production well system of  claim 63 , wherein the means for injecting the steam injects the steam continuously, and the production of hydrocarbon liquids is also continuous. 
     
     
         69 . The production well system of  claim 63 , wherein the means for injecting the steam injects the steam intermittently as a pressure pulsed cycle. 
     
     
         70 . The production well system of  claim 63 , wherein steam pressure in the process zone is at ambient reservoir pressure. 
     
     
         71 . The production well system of  claim 63 , wherein the production well system includes means for injecting into the process zone a non-condensing gas, a hydrocarbon solvent in a vaporized state, or a mixture thereof. 
     
     
         72 . The production well system of  claim 71 , wherein the solvent is one of a group of ethane, propane, butane, or a mixture thereof. 
     
     
         73 . The production well system of  claim 71 , wherein the solvent is mixed with a diluent gas. 
     
     
         74 . The production well system of  claim 73 , wherein the diluent gas is non-condensable under the process conditions. 
     
     
         75 . The production well system of  claim 74 , wherein the non-condensable diluent gas has a lower solubility in the hydrocarbon deposit liquid than the saturated hydrocarbon solvent. 
     
     
         76 . The production well system of  claim 75 , wherein the diluent gas is one of a group of methane, nitrogen, carbon dioxide, natural gas, or a mixture thereof. 
     
     
         77 . The production well system of  claim 63 , wherein the production well system includes means for injecting a hydrogenizing gas into the wellbore and thus into the fluids in the process zone to promote hydrogenation and thermal cracking reactions of at least a portion of the petroleum fluids in the process zone. 
     
     
         78 . The production well system of  claim 77 , wherein the hydrogenising gas consists of one of the group of H2 and CO or a mixture thereof. 
     
     
         79 . The production well system of  claim 77 , wherein the production well system includes means for catalyzing the hydrogenation and thermal cracking of at least a portion of the petroleum fluids in the process zone. 
     
     
         80 . The production well system of  claim 79 , wherein a metal-containing catalyst is used to catalyze said hydrogenation and thermal cracking reactions. 
     
     
         81 . The production well system of  claim 80 , wherein the catalyst is contained in a canister in tubing inside of the wellbore. 
     
     
         82 . The production well system of  claim 80 , wherein the proppant particles in the inclusions contain the catalyst for the hydrogenation and thermal cracking reactions. 
     
     
         83 . The production well system of  claim 43 , wherein a portion of the formation in which the first inclusion is formed has a Skempton B parameter greater than 0.95 exp(−0.04 p′)+0.008 p′, where p′ is a mean effective stress in MPa at the depth of the first inclusion and the water saturation in the formation pores is greater or equal to 10%.