Single vertical or inclined well thermal recovery process

Abstract

The present disclosure describes a single well predominantly gravity-dominated recovery process for producing viscous hydrocarbons from a subterranean oil sands formation. The process operates a single vertical or inclined well within a formation, the wellbore having an injection means and a production means, the injection means being positioned in the wellbore closer to the surface than the production means. The process provides an area of high mobility adjacent the production means. A mobilizing fluid is injected through the injection means into the formation to mobilize the viscous hydrocarbons in the formation while substantially concurrently producing hydrocarbons through the production means. The gravity dominated process may be SAGD and the present process may be a single vertical or inclined well SAGD process.

1 . A method of producing viscous hydrocarbons from a subterranean oil sands formation, comprising the steps of:
 i. operating a vertical or inclined well within a formation, the well having an injection means and a production means, the injection means being positioned in the well closer to the surface than the production means, and wherein the injection means is positioned in the wellbore in the absence of an induced fracture in the formation adjacent the injection means;   ii. providing an area of high mobility in the formation adjacent the production means;   iii. injecting a mobilizing fluid through the injection means into the formation, to mobilize the viscous hydrocarbons in the formation; and   iv. substantially concurrently producing the viscous hydrocarbons through the production means;   v. wherein the viscous hydrocarbons are produced using a predominantly gravity-dominated process.   
     
     
         2 . The method of  claim 1  wherein the formation adjacent the injection means has an absence of an area of high mobility. 
     
     
         3 . The method of  claim 1  wherein the injection and production means are isolated from each other within the well. 
     
     
         4 . The method of  claim 1  wherein the injecting and/or producing is done on a continuous or an interrupted basis. 
     
     
         5 . The method of  claim 1  wherein providing an area of high mobility comprises mobilizing the hydrocarbons in the formation in an area adjacent the production means to form the area of high mobility. 
     
     
         6 . The method of  claim 5  wherein mobilizing the hydrocarbons comprises introducing heat into the area. 
     
     
         7 . The method of  claim 6  wherein introducing heat into the area comprises using electric heating, electromagnetic heating, or injecting heated fluids into the area. 
     
     
         8 . The method of  claim 7  wherein the heated fluids comprise steam, hot water, solvent, and a combination thereof. 
     
     
         9 . The method of  claim 1  wherein providing an area of high mobility comprises altering the matrix structure of the area. 
     
     
         10 . The method of  claim 9  wherein altering the matrix structure comprises dilation of the formation area. 
     
     
         11 . The method of  claim 1  wherein providing the area of high mobility comprises replacing native fluids in the area with high mobility fluids. 
     
     
         12 . The method of  claim 11  wherein high mobility fluids comprise water, light hydrocarbons, non-condensing gases and combinations thereof. 
     
     
         13 . The method of  claim 1  wherein providing the area of high mobility comprises removing formation material in the area and filling the area with high permeability material. 
     
     
         14 . The method of  claim 13  wherein removing formation material comprises mining, drilling or under-reaming the formation to create a cavity. 
     
     
         15 . The method of  claim 13  wherein the high permeability material comprises gravel. 
     
     
         16 . The method of  claim 1  wherein the area having high mobility is a pre-existing area of high mobility. 
     
     
         17 . The method of  claim 1  wherein the injected mobilizing fluid is steam, light hydrocarbon, hot water, or a mixture thereof. 
     
     
         18 . The method of  claim 1  wherein the gravity-dominated recovery process is steam-assisted gravity drainage (SAGD). 
     
     
         19 . The method of  claim 1  further comprising maintaining a liquid level in the formation to avoid introduction of uncondensed injected mobilizing fluids into the production means. 
     
     
         20 . The method of  claim 1  wherein steam is initially injected through both the injection and production means to mobilize the viscous hydrocarbons and establish communication in the formation between the injection and production means. 
     
     
         21 . The method of  claim 1  wherein the mobilizing fluid is circulated through the well to mobilize the viscous hydrocarbons and establish communication in the formation between the injection and production means. 
     
     
         22 . The method of  claim 1  wherein the viscous hydrocarbons are selected from the group consisting of bitumen, heavy oil, and unmobilized hydrocarbons. 
     
     
         23 . The method of  claim 8  wherein the solvent comprises one or more of a C 3  to C 10  solvent. 
     
     
         24 . The method of  claim 23  wherein the solvent is hexane. 
     
     
         25 . The method of  claim 23  wherein the heated fluids comprise up to 12 wt % solvent. 
     
     
         26 . The method of  claim 23  wherein the heated fluids comprise the steam and the solvent which are injected substantially simultaneously or alternating. 
     
     
         27 . The method of  claim 12  wherein the high mobility fluids comprise one or more of a C 3  to C 10  solvent. 
     
     
         28 . The method of  claim 27  wherein the solvent is hexane. 
     
     
         29 . The method of  claim 27  wherein the high mobility fluids comprise up to 12 wt % solvent. 
     
     
         30 . The method of  claim 29  wherein the high mobility fluids comprise the steam and solvent which are injected substantially simultaneously or alternating. 
     
     
         31 . The method of  claim 1  wherein the mobilizing fluid further comprises one or more of surfactants and non-condensing gases.