In situ combustion following sagd

Abstract

There is provided herein a method for recovering petroleum from a formation, wherein said formation is intersected by at least one wellpair consisting of a horizontal production well and a horizontal injection well, and wherein said formation comprises at least one steam chamber developed by a steam-assisted process, said method comprising: providing an oxidizing agent near the top of said formation; initiating in situ combustion (ISC); and recovering petroleum from said at least one production well.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a non-provisional application which claims the benefit of and priority to U.S. Provisional Application Ser. No. 61 / 448,868 filed Mar. 3, 2011, entitled “In Situ Combustion Following SAGD,” which is hereby incorporated by reference in its entirety.FEDERALLY SPONSORED RESEARCH STATEMENT[0002]Not applicable.FIELD OF THE INVENTION[0003]The invention relates to recovery of petroleum from a petroliferous formation, in particular to in situ processing of a reservoir containing heavy oil and / or bitumen.BACKGROUND OF THE INVENTION[0004]Production of heavy oil and bitumen from a subsurface reservoir can be quite challenging, especially when the viscosity of the oil at reservoir temperature is often greater than a million centipoise (cP). High viscosity oil cannot be pumped out of the ground using typical methods, but must be mined or processed in situ. Surface mining is limited to reservoirs to a depth of about 70 meters. Greate...

AI Technical Summary

Benefits of technology

The patent describes a method called steam-assisted gravity drainage (SAGD) that can be used to recover oil from a reservoir using steam. This method can also be used to repressurize the reservoir before it is ready to be produced. The technical effect of this patent is that it provides an effective way to recover more oil from a reservoir and to prepare it for further production.

Problems solved by technology

Production of heavy oil and bitumen from a subsurface reservoir can be quite challenging, especially when the viscosity of the oil at reservoir temperature is often greater than a million centipoise (cP).

High viscosity oil cannot be pumped out of the ground using typical methods, but must be mined or processed in situ.

Greater depths are not economical to access and most reserves are not accessible by mining.

Heating rods and other approaches can achieve this outcome, but they are not as yet economical.

These applications fail to teach or suggest use of in situ combustion after a formation is developed with a steam-assisted process, and describe recovery only at steam chamber walls rather than from the formation as a whole, such as edges of the formation and residual oil within the steam chamber.

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