Oil and gas field chemicals
First Claim
1. A method for conformance control of a reservoir comprising:
- injecting into a zone of the reservoir an aqueous solution of a co-polar comprising at least one ethylenically unsaturated polar monomer and at least one copolymerizable ethylenically unsaturated ester formed from a hydroxy compound of the formula ROH wherein R is an alkyl group of 4-30 carbons, alkenyl group of 4-20 carbons, cycloalkyl group of 5-8 carbons, aryl group of 6-20 carbons or such groups, substituted with from 1 to 3 hydroxyl, ether or thio ether groups or a heterocyclic or heterocyclic alkylene group of from 3-8 carbons and at least one heteroatom selected from oxygen, nitrogen and sulfur and an alkenoic or aralkenoic carboxylic acid having from 4-20 carbons or sulfonic or phosphoric acid having from 2-20 carbons together with a crosslinking agent comprising a multi-valent metal ion capable of crosslinking an acrylic acid polymer to form a viscous gel;
allowing the solution to flow through at least a portion of a high permeability region within said zone wherein it is heated to a temperature of at least about 20°
C. while maintained at a pH above about 6.5 whereupon crosslinking occurs to form a substantially non-flowable gel within said high permeability region which reduces the permeability of said region in said zone.
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Accused Products
Abstract
A method for conformance control of a reservoir comprising injecting into a zone of the reservoir an aqueous solution of a co-polymer comprising at least one ethylenically unsaturated polar monomer and at least one copolymerizable ethylenically unsaturated ester formed from a hydroxy compound of the formula ROH wherein R is a selected alkyl group, alkenyl group, cycloalkyl group, aryl group or such groups substituted with from 1 to 3 hydroxyl, ether or thio ether groups or a heterocyclic or selected heterocyclic alkylene group and at least one hetereatom selected from oxygen, nitrogen and sulfur and a selected alkenoic or aralkenoic carboxylic acid or sulfonic or phosphoric acid together with a crosslinking agent comprising a multi-valent metal ion capable of crosslinking an acrylic acid polymer to form a viscous gel. The injected fluid is flowed through at least a portion of a high permeability region within said zone wherein it is heated to an elevated temperature whereupon crosslinking of the polymers occurs to form a substantially non-flowable gel within said high permeability region. The crosslinking of the injected fluid to form the non-flowable gel within the formation reduces the permeability of said region in said zone.
190 Citations
18 Claims
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1. A method for conformance control of a reservoir comprising:
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injecting into a zone of the reservoir an aqueous solution of a co-polar comprising at least one ethylenically unsaturated polar monomer and at least one copolymerizable ethylenically unsaturated ester formed from a hydroxy compound of the formula ROH wherein R is an alkyl group of 4-30 carbons, alkenyl group of 4-20 carbons, cycloalkyl group of 5-8 carbons, aryl group of 6-20 carbons or such groups, substituted with from 1 to 3 hydroxyl, ether or thio ether groups or a heterocyclic or heterocyclic alkylene group of from 3-8 carbons and at least one heteroatom selected from oxygen, nitrogen and sulfur and an alkenoic or aralkenoic carboxylic acid having from 4-20 carbons or sulfonic or phosphoric acid having from 2-20 carbons together with a crosslinking agent comprising a multi-valent metal ion capable of crosslinking an acrylic acid polymer to form a viscous gel; allowing the solution to flow through at least a portion of a high permeability region within said zone wherein it is heated to a temperature of at least about 20°
C. while maintained at a pH above about 6.5 whereupon crosslinking occurs to form a substantially non-flowable gel within said high permeability region which reduces the permeability of said region in said zone. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of blocking a high permeability region in a zone of a subterranean formation penetrated by a wellbore comprising:
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injecting into a zone of a subterranean formation having a temperature of from about 60°
-150°
C. an aqueous solution of a copolymer comprising at least one ethylenically unsaturated polar monomer and at least one copolymerizable ethylenically unsaturated ester formed from a hydroxy compound of the formula ROH wherein R is an alkyl group of 4-30 carbons, alkenyl group of 4-20 carbons, cycloalkyl group of 5-8 carbons, aryl group of 6-20 carbons or such groups, substituted with from 1 to 3 hydroxyl, ether or thio ether groups or a heterocyclic or heterocyclic alkylene group of from 3-8 carbons and at least one heteroatom selected from oxygen, nitrogen and sulfur and an alkenoic or aralkenoic carboxylic acid having from 4-20 carbons or sulfonic or phosphoric acid having from 2-20 carbons together with a crosslinking agent comprising a multi-valent metal ion capable of crosslinking an acrylic acid polymer to form a viscous gel;shutting-in said wellbore for from about 1 to about 70 hours. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method for reducing the permeability of a relatively higher permeability zone of a subterranean sandstone formation penetrated by a wellbore comprising
introducing into the relatively higher permeability zone of said formation through said wellbore a quantity of an aqueous solution of a copolymer comprising at least one copolymerizable ethylenically unsaturated ester formed from a hydroxy compound of the formula ROH wherein R is an alkyl group of 4-30 carbons, alkenyl group of 4-20 carbons, cycloalkyl group of 5-8 carbons, aryl group of 6-20 carbons or such groups, substituted with from 1 to 3 hydroxyl, ether or thio ether groups or a heterocyclic or heterocyclic alkylene group of from 3-8 carbons and at least one heteroatom selected from oxygen, nitrogen and sulfur and an alkenoic or aralkenoic carboxylic acid having from 4-20 carbons or sulfonic or phosphoric acid having from 2-20 carbons together with a crosslinking agent comprising a multi-valent metal ion capable of crosslinking an acrylic acid polymer to form a viscous gel; - and
heating said aqueous solution to a temperature in excess of about 90°
C. within said formation while subjecting said solution to an acidic pH of below about 6.5 whereupon a crosslinking reaction occurs to form a substantially non-flowable gel in said formation to substantially non-flowable gel in said formation to substantially decrease the permeability of the portion of said formation occupied by said gel. - View Dependent Claims (14, 15, 16, 17, 18)
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Specification