Systems and methods for producing oil and/or gas

Abstract

A method for producing oil and/or gas from an underground formation comprising locating a suitable formation with an oil column located above an aquifer; drilling at least one horizontal production well near a top of the oil column; performing primary production to produce a first quantity of fluids from the oil column; drilling at least one horizontal injection well at a location between the horizontal production well and a bottom of the oil column; injecting water mixed with a viscosifier into the horizontal injection well while producing a second quantity of fluids through the horizontal production well from the oil column.

1 . A method for producing oil and/or gas from an underground formation comprising:
 locating a suitable formation with an oil column located above an aquifer;   drilling at least one horizontal production well near a top of the oil column;   performing primary production to produce a first quantity of fluids from the oil column;   drilling at least one horizontal injection well at a location between the horizontal production well and a bottom of the oil column;   injecting water mixed with a viscosifier into the horizontal injection well while producing a second quantity of fluids through the horizontal production well from the oil column.   
     
     
         2 . The method of  claim 1 , wherein the horizontal production well is at a distance of 25 meters to 100 meters from the horizontal injection well. 
     
     
         3 . The method of  claim 1 ,
 wherein the oil column comprises a oil column height from a top of the oil column to an interface between the oil column and the aquifer at the bottom of the oil column;   wherein the horizontal production well is at a location within 20% of the oil column height from the top of the oil column.   
     
     
         4 . The method of  claim 1 , further comprising a mechanism for injecting a water based mixture into the formation, after the water mixed with a viscosifier has been released into the formation. 
     
     
         5 . The method of  claim 1 ,
 wherein the oil column comprises a oil column height from a top of the oil column to an interface between the oil column and the aquifer at the bottom of the oil column;   wherein the horizontal injection well is at a location between 30% and 70% of the oil column height from the top of the oil column.   
     
     
         6 . The method of  claim 1 ,
 wherein the oil column comprises a oil column height from a top of the oil column to an interface between the oil column and the aquifer at the bottom of the oil column;   wherein a distance between the horizontal injection well and the horizontal production well is between 30% and 70% of the oil column height.   
     
     
         7 . The method of  claim 1 , wherein drilling at least one horizontal production well further comprises drilling an array of production wells comprising from 5 to 500 wells, and wherein drilling at least one horizontal injection well further comprises drilling an array of injection wells comprising from 5 to 500 wells. 
     
     
         8 . The method of  claim 7 , wherein each of the production wells are at a distance from about 50 m to about 100 m from each other, measured horizontally. 
     
     
         9 . The method of  claim 1 , wherein the oil column has a height from about 25 m to about 50 m, measured vertical. 
     
     
         10 . The method of  claim 1 , wherein the oil column comprises an oil having a viscosity from 50 to 250 centipoise, prior to the injection of the water mixture. 
     
     
         11 . The method of  claim 1 , wherein the horizontal production well comprises a water mixture profile in the formation, and the horizontal injection well comprises an oil recovery profile in the formation, the method further comprising an overlap between the water mixture profile and the oil recovery profile. 
     
     
         12 . The method of  claim 1 , wherein a first horizontal production well and a second horizontal production well comprise a pair of adjacent production wells which are separated by a horizontal production well separation distance, further wherein the horizontal injection well is located from about 40% to about 60% of the horizontal production well separation distance. 
     
     
         13 . The method of  claim 12 , wherein the viscosifier comprises a water soluble polymer. 
     
     
         14 . The method of  claim 1 , wherein the oil in the formation comprises a first viscosity, and the water mixture comprises a second viscosity, the first viscosity is within 75 centipoise of the second viscosity. 
     
     
         15 . The method of  claim 1 , wherein the oil in the formation comprises a first viscosity, and the water mixture comprises a second viscosity, the second viscosity is from about 25% to about 100% of the first viscosity. 
     
     
         16 . The method of  claim 1 , wherein the horizontal production well produces the water mixture, and oil and/or gas. 
     
     
         17 . The method of  claim 1 , further comprising recovering the water mixture from the oil and/or gas, if present, and then optionally re-injecting at least a portion of the recovered water mixture into the formation. 
     
     
         18 . The method of one  claim 1 , wherein the water mixture is injected at a pressure from 0 to 37,000 kilopascals above the initial reservoir pressure, measured prior to when injection begins. 
     
     
         19 . The method of  claim 1 , wherein the oil column comprises a permeability from 0.0001 to 15 Darcies, for example a permeability from 0.001 to 1 Darcy. 
     
     
         20 . The method of  claim 1 , further comprising converting at least a portion of the recovered oil and/or gas into a material selected from the group consisting of transportation fuels such as gasoline and diesel, heating fuel, lubricants, chemicals, and/or polymers. 
     
     
         21 . A method for producing oil and/or gas from an underground formation comprising:
 locating a suitable formation with an oil column located above an aquifer, and at least two horizontal production well near a top of the oil column, which oil column has already undergone primary production to produce a first quantity of fluids from the oil column;   drilling at least one horizontal injection well at a vertical location between the horizontal production well and a bottom of the oil column, and at a horizontal location between the two horizontal production wells;   injecting water mixed with a viscosifier into the horizontal injection well while producing a second quantity of fluids through the horizontal production wells from the oil column.