Oil displacement method using shear-thickening compositions

Claim 2

A process for displacing oil within a subterranean formation which comprises injecting into the formation through an injection well an aqueous shear-thickening composition comprising (a) a small but effective amount of a high molecular weight polyalkylene oxide and (b) a small but effective amount of a synthetic resin comprising the reaction product formed by heating an aqueous alkaline mixture of an aldehyde having from one to four carbon atoms and a phenol compound, the amounts of (a) and (b) being sufficient to form a sher-thickening composition that is fluid in a quiescent state but becomes gel-like in character on agitation, and (c) the balance of the composition being water at a pressure sufficient to force said composition into the more permeable portions of said formation and temporarily plug same and introducing into the formation a drive fluid at a pressure sufficient to force oil from the less permeable oil-rich zones of the formation toward a production well and to the surface.

Claim 3

A process according to claim 1 wherein (a) is present in an amount ranging from 0.1 to 3.0 weight percent, (b) is present in an amount ranging from 0.025 to 2.5 weight percent, and (a) has a molecular weight range of 10,000 to 10,000,000.

Claim 4

A process according to claim 1 wherein said shear-thickening composition comprises (a) a small but effective amount in the range of 0.1 to 3.0 weight percent of a high molecular weight polyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxides, and polybutylene oxides and having a molecular weight of about 10,000 to about 10,000,000 and (b) a small but effective amount in the range of 0.025 to 2.5 weight percent of a synthetic resin comprising the reaction product formed by heating said aqueous alkaline mixture of an aldehyde and a phenol compound selected from the group consisting of phenol, catechol, resorcinol, and cresol at a reaction temperature in the range of 100° to 212° F. for a period of time in the range of 5 minutes to 48 hours in a molar ratio of adehyde to phenol in the range of 0.1:1 to 2:1, and a pH in the range of about 7 to 12, the amounts of (a) and (b) being sufficient to form a shear-thickening composition that is fluid in a quiescent state but becomes gel-like in character on agitation, and (c) the balance of the composition being water.

Claim 5

A process according to claim 1 wherein (a) is a polyethylene oxide and (b) is the reaction product formed from formaldehyde and phenol.

Claim 6

A process according to claim 1 wherein (a) has a molecular weight range of 600,000 to 7,500,000 and (b) is a synthetic resin formed by heating a mixture of formaldehyde and phenol or resorcinol.

Claim 7

A process for displacing oil within a subterranean reservoir comprising: injecting into the reservoir a slug of surface-active liquid that has a relatively low interfacial tension between it and the oil to be displaced and injecting immediately behind said surface-active liquid an aqueous shear-thickening composition comprising (a) a small but effective amount of a high molecular weight polyalkylene oxide, (b) a small but effective amount of a synthetic resin comprising the reaction product formed by heating an aqueous alkaline mixture of an aldehyde having from one to four carbon atoms and a phenol compound, the amounts of (a) and (b) being sufficient to form a shear-thickening composition that is fluid in a quiescent state but becomes gel-like in character on agitation, and (c) the balance of the composition being water.

Claim 8

A process for displacing oil within a subterranean reservoir comprising: injecting into the reservoir a slug of surface-active liquid that has a relatively low interfacial tension between it and the oil to be displaced and injecting immediately behind said surface-active liquid an aqueous shear-thickening composition comprising (a) a small but effective amount of a high molecular weight polyalkylene oxide, (b) a small but effective amount of a synthetic resin comprising the reaction product formed by heating an aqueous alkaline mixture of an aldehyde having from one to four carbon atoms and a phenol compound, the amounts of (a) and (b) being sufficient to form a shear-thickening composition that is fluid in a quiescent state but becomes gel-like in character on agitation, and (c) the balance of the composition being water.

Claim 9

A process according to claim 6 wherein (a) is present in an amount ranging from 0.1 to 3.0 weight percent, (b) is present in an amount ranging from 0.025 to 2.5 weight percent, and (a) has a molecular weight range of 10,000 to 10,000,000.

Claim 10

A process according to claim 6 wherein said shear-thickening composition comprises (a) a small but effective amount in the range of 0.1 to 3.0 weight percent of a high molecular weight polyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxides, and polybutylene oxides and having a molecular weight of about 10,000 to about 10,000,000 and (b) a small but effective amount in the range of 0.025 to 2.5 weight percent of a synthetic resin comprising the reaction product formed by heating said aqueous alkaline mixture of an aldehyde and a phenol compound selected from the group consisting of phenol, catechol, resorcinol, and cresol at a reaction temperature in the range of 100° to 212° F. for a period of time in the range of 5 minutes to 48 hours in a molar ratio of aldehyde to phenol in the range of 0.1:1 to 2:1, and a pH in the range of about 7 to 12, the amounts of (a) and (b) being sufficient to form a shear-thickening composition that is fluid in a quiescent state but becomes gel-like in character on agitation, and (c) the balance of the composition being water.

Claim 11

A process according to claim 6 wherein (a) is a polyethylene oxide and (b) is the reaction product formed from formaldehyde and phenol.

Claim 12

A process according to claim 6 wherein (a) has a molecular weight range of 600,000 to 7,500,000 and (b) is a synthetic resin formed by heating a mixture of formaldehyde and phenol or resorcinol.