Patent ID: 8360157
Filing Date: 2013-01-29
Classification: E21B

Abstract:
1. A method for recovering heavy oil, comprising: accessing, from two or more locations, a subsurface formation having an overburden stress disposed thereon, the formation comprising heavy oil and one or more solids; pressurizing the formation at a pressure; causing a differential pressure between the two or more locations to provide one or more high pressure locations and one or more low pressure locations; varying the differential pressure within the formation between the one or more high pressure locations and the one or more low pressure locations so as to mobilize at least a portion of the solids and a portion of the heavy oil in the formation; causing the mobilized solids and heavy oil to flow toward the one or more low pressure locations to provide a slurry comprising heavy oil and one or more solids; flowing the slurry comprising the heavy oil and solids to the surface; recovering the heavy oil from the one or more solids; and recycling the one or more solids to the formation, wherein varying the differential pressure within the formation comprises pulsing the flow of the slurry in the formation.