Apparatus, system, and method for in-situ extraction of oil from oil shale

Abstract

An apparatus, system, and method are disclosed for in-situ extraction of oil from oil shale. The method comprises drilling a fluid conduit in fluid communication with a top and a bottom of a target zone within an oil shale formation. The method includes stimulating the target zone. The method further includes injecting a heated fluid into the bottom of the target zone such that the heated fluid entrains the kerogen within the target zone into the injected fluid to generate a production fluid. The method concludes with producing the production fluid, containing the in-situ kerogen, from the top of the target zone to the surface.

1 . An apparatus for extracting oil from oil shale, the apparatus comprising: 
 a drilling unit configured to drill at least one fluid conduit to a top of a target zone and a bottom of the target zone of an oil shale formation;    a stimulation module configured to stimulate the target zone;    a completion unit configured to position an injection tube substantially at the bottom of the target zone;    an injection unit configured to inject a fluid into the target zone;    a thermal delivery unit configured to heat the fluid such that the heated fluid entrains in-situ kerogen to generate a production fluid; and    a production module to produce the production fluid.    
   
   
       2 . The apparatus of  claim 1 , wherein the injection unit is further configured to inject the fluid into the target zone such that the fluid displaces free water within the target zone.  
   
   
       3 . The apparatus of  claim 1 , wherein the thermal delivery unit is further configured to heat the fluid such that the fluid temperature exceeds 300 degrees C. at the bottom of the target zone.  
   
   
       4 . The apparatus of  claim 1 , wherein the thermal delivery unit is further configured to heat the fluid such that the fluid temperature exceeds 400 degrees C. at the bottom of the target zone.  
   
   
       5 . The apparatus of  claim 1 , wherein the thermal delivery unit is further configured to heat the fluid at the surface, and wherein the injection tube comprises a vacuum insulated tube.  
   
   
       6 . The apparatus of  claim 5 , wherein heating the fluid at the surface comprises heating the fluid with at least one solar concentrator.  
   
   
       7 . The apparatus of  claim 5 , wherein heating the fluid at the surface comprises heating the fluid with a natural gas burner.  
   
   
       8 . The apparatus of  claim 1 , wherein the thermal delivery unit comprises a downhole burner configured to heat the fluid within the at least one fluid conduit.  
   
   
       9 . The apparatus of  claim 1 , further comprising a treatment module configured to heat the production fluid to a target temperature and to react the production fluid in a catalytic reactor.  
   
   
       10 . The apparatus of  claim 9 , wherein the target temperature comprises a temperature greater than 350 degrees Celsius.  
   
   
       11 . The apparatus of  claim 1  wherein the drilling unit comprises a coiled tubing drilling unit.  
   
   
       12 . The apparatus of  claim 1 , wherein the stimulation module comprises an explosive.  
   
   
       13 . The apparatus of  claim 1 , wherein the production module comprises a production tube positioned substantially at the top of the target zone.  
   
   
       14 . The apparatus of  claim 1 , wherein: 
 the target zone comprises a first target zone;    wherein the stimulation module is further configured to stimulate a second target zone;    wherein the completion unit is further configured to position the injection tube substantially at the bottom of the second target zone;    the apparatus further comprising an isolation unit configured to isolate the at least one fluid conduit from the first target zone;    wherein the injection unit is further configured to inject the fluid into the second target zone; and    wherein the thermal delivery unit is further configured to heat the fluid such that energy of the heated fluid entrains in-situ kerogen within the second target zone to generate the production fluid.    
   
   
       15 . The apparatus of  claim 14 , wherein the isolation unit comprises one of a bridge plug and a cement plug.  
   
   
       16 . A method for extracting oil from oil shale, the method comprising: 
 drilling at least one fluid conduit to a top of a target zone and a bottom of the target zone of an oil shale formation;    stimulating the target zone;    positioning an injection tube substantially at the bottom of the target zone;    injecting a fluid into the target zone;    heating the fluid such that the heated fluid entrains in-situ kerogen to generate a production fluid; and    producing the production fluid.    
   
   
       17 . The method of  claim 16 , wherein injecting fluid into the target zone further comprises injecting the fluid into the target zone at a pressure higher than a formation fluid pressure and lower than a formation fracture pressure, such that the fluid displaces free water within the target zone.  
   
   
       18 . The method of  claim 16 , further comprising heating the production fluid to a target temperature, and treating the production fluid in a catalytic reactor to reduce the average molecular weight of the entrained kerogen.  
   
   
       19 . The method of  claim 18 , further comprising adding natural gas to the production fluid such that a minimal amount of hydrogen is available for reaction within the catalytic reactor.  
   
   
       20 . The method of  claim 16 , further comprising positioning a production tube substantially at the top of the target zone, and wherein producing the production fluid comprises flowing the production fluid up the production tubing.  
   
   
       21 . The method of  claim 16 , further comprising setting a production casing through the oil shale formation, perforating the production casing substantially near the bottom of the target zone, perforating the production casing substantially near the top of the target zone, wherein positioning the injection tube further comprises positioning the injection tube within the production casing, and wherein producing the production fluid comprises flowing the production fluid up the annulus formed between the production casing and the injection tubing.  
   
   
       22 . The method of  claim 21 , wherein flowing the production fluid up the annulus formed by the casing and the injection tube comprises flowing the product up a production tube within the annulus.  
   
   
       23 . The method of  claim 16 , wherein the fluid comprises natural gas.  
   
   
       24 . The method of  claim 23 , wherein heating the fluid comprises at least one member selected from the group consisting of heating the fluid with a solar concentrator, and heating the fluid with a gas burner configured to burn a portion of the production fluid.  
   
   
       25 . The method of  claim 23 , wherein heating the fluid comprises circulating the fluid through a substantially depleted zone in an offset well, the substantially depleted zone comprising a shale formation substantially depleted of kerogen.  
   
   
       26 . The method of  claim 16 , wherein the fluid comprises at least one member selected from the group consisting of methane, ethane, propane, butane, hydrocarbon gas, hydrogen, carbon monoxide, nitrogen, helium, argon, and neon.  
   
   
       27 . The method of  claim 16 , wherein heating the fluid comprises heating the fluid with a downhole burner within the at least one fluid conduit.  
   
   
       28 . The method of  claim 16 , wherein drilling at least one fluid conduit to a top of a target zone and a bottom of the target zone of an oil shale formation comprises drilling a vertical well through the oil shale formation, and wherein the target zone comprises a target zone thickness (TZT).  
   
   
       29 . The method of  claim 28 , wherein the TZT comprises a thickness between 25 feet and 100 feet.  
   
   
       30 . The method of  claim 28 , further comprising drilling a plurality of vertical wells through the oil shale formation, wherein each of the plurality of vertical wells is spaced at a distance between about 0.5 times the TZT and about 2.0 times the TZT.  
   
   
       31 . The method of  claim 28 , wherein the target zone comprises a first target zone, the method further comprising stimulating a second target zone, positioning the injection tube substantially at the bottom of the second target zone, isolating the at least one fluid conduit from the first target zone, injecting the fluid into the second target zone, heating the fluid such that the heated fluid entrains in-situ kerogen within the second target zone to generate a production fluid, and producing the production fluid.  
   
   
       32 . The method of  claim 16 , wherein drilling at least one fluid conduit to a top of a target zone and a bottom of the target zone of an oil shale formation comprises drilling a first horizontal well segment in fluid communication with the top portion of the target zone, and drilling a second horizontal well segment in fluid communication with the bottom portion of the target zone.  
   
   
       33 . The method of  claim 32 , wherein the target zone comprises a horizontal width equal to the height of the target zone.  
   
   
       34 . The method of  claim 32 , wherein the target zone comprises a first target zone, further comprising drilling a third horizontal well segment in fluid communication with the top portion of a second target zone, wherein the first horizontal well segment is in fluid communication with a bottom portion of the second target zone, the method further comprising stimulating the second target zone, positioning the injection tube substantially at the bottom of the second target zone, isolating the at least one fluid conduit from the first target zone, injecting the fluid into the second target zone, heating the fluid such that the heated fluid entrains in-situ kerogen within the second target zone to generate the production fluid, and producing the production fluid.  
   
   
       35 . A system for in-situ extraction of oil from oil shale, the system comprising: 
 a three-phase separator configured to separate a production fluid into oil, water, and natural gas;    fluid coupling configured to deliver separated water to a water disposal system, to deliver separated oil to an oil storage facility, and to deliver separated natural gas to a natural gas storage facility;    a drilling unit configured to drill at least one fluid conduit to a top of a target zone and a bottom of the target zone of an oil shale formation;    a stimulation module configured to stimulate the target zone;    a completion unit configured to position an injection tube substantially at the bottom of the target zone;    an injection unit configure to inject a fluid into the target zone;    a thermal delivery unit configured to heat the fluid such that the heated fluid entrains in-situ kerogen to generate a product fluid;    a production module to produce the production fluid;    a treatment module configured to heat the production fluid to a target temperature and to react the production fluid in a catalytic reactor; and    a condensing module configured to cool the reacted production fluid and to deliver the reacted production fluid to the three-phase separator.    
   
   
       36 . The system of  claim 35 , further comprising an oil heater configured to receive heat from a solar concentrator and to receive heat from a natural gas burner, wherein the thermal delivery unit is further configured to heat the fluid using heat from the oil heater, and wherein the injection tube comprises a vacuum insulated tube.