US 2012/0234535 A1 · Method Of Injecting Solvent Into An Underground Reservoir To Aid Recovery Of Hydrocarbons

Abstract

Described is a method of operating a cyclic solvent-dominated recovery process (CSDRP) for recovering viscous oil from a subterranean reservoir of the viscous oil. The cyclic solvent process involves using an injection well to inject a viscosity-reducing solvent into a subterranean viscous oil reservoir. Reduced viscosity oil is produced to the surface using the same well used to inject solvent. The process of alternately injecting solvent and producing a solvent/viscous oil blend through the same wellbore continues in a series of cycles until additional cycles are no longer economical. To improve solvent efficiency, the injection includes at least one restriction duration, where injection is restricted, between two continuous injection periods.

Claims44

Dependent claims

A method of controlling a cyclic solvent injection and production process to aid recovery of hydrocarbons from an underground reservoir, the method comprising:

(a) injecting a volume of fluid comprising greater than 50 mass % of a viscosity-reducing solvent into an injection well completed in the reservoir;
(b) halting injection into the injection well and subsequently producing at least a fraction of the injected fluid and the hydrocarbons from the reservoir through a production well;
(c) halting production through the production well;
and
(d) subsequently repeating the cycle of steps (a) to (c);
wherein step (a) comprises at least one restriction duration, where injection is restricted, between two continuous injection periods, for improving solvent efficiency.

3 more elements

Dependencies are inferred from the claim text.

Method Of Injecting Solvent Into An Underground Reservoir To Aid Recovery Of Hydrocarbons

Life of this patent

Method Of Injecting Solvent Into An Underground Reservoir To Aid Recovery Of Hydrocarbons

Life of this patent

Abstract

Claims44