Methods for stabilizing swelling clays or migrating fines in subterranean formations
AssigneeHalliburton Company
InventorsJohn K. Borchardt, Bill M. Young
Life of this patent
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Abstract
A method of treating an earthen formation containing swelling clays or migrating fines or combinations thereof to reduce the loss of permeability in said formation. The method is carried out by contacting the swelling clays or fines with an effective amount of an organic polycationic polymer which contains three quaternary ammonium moieties in the monomer repeat unit.
Claims19
A method of preventing or reducing the migration of fines or the swelling of clays or combinations thereof in a permeable subterranean formation comprising:
- contacting said fines or swelling clays or combinations thereof with an effective amount of an organic polycationic polymer having a molecular weight in the range of from about 50,000 to about 300,000 and having monomer units of the formula:
- ##STR11## wherein R and R.sup.3 are independently an alkylene group having from about 2 to about 4 carbon atoms;
- R.sup.1, R.sup.2, R.sup.4, R.sup.5, R.sup.7, R.sup.8, and R.sup.9 are independently selected from the group consisting of methyl and ethyl;
- R.sup.6 is selected from the group consisting of an unsubstituted alkylene group having from about 2 to about 4 carbon atoms and a substituted alkylene group having from about 2 to about 4 carbon atoms and containing a hydroxy group;
- X is an anion selected from the group consisting of a halogen, methyl sulfate, sulfate, and nitrate;
- n represents the valency of the anion represented by X;
- and,
- a is an integer equal to the number of said anions required to maintain electronic neutrality.
The method recited in claim 7 wherein said polymer is dispersed in a carrier fluid.
A method of treating a earthen formation comprising migrating fines or swelling clays or combinations thereof to reduce loss of permeability in said formation because of the migration of said fines or the swelling of said clays or combinations thereof comprising:
- contacting said fines or swelling clays or combinations thereof with an effective amount of an organic polycationic polymer having a molecular weight in the range of from about 50,000 to about 300,000 and having monomer units of the formula:
- ##STR12## wherein R and R.sup.3 are independently an alkylene group having from about 2 to about 4 carbon atoms;
- R.sup.1, R.sup.2, R.sup.4, R.sup.5, R.sup.7, R.sup.8, and R.sup.9 are independently selected from the group consisting of methyl and ethyl;
- R.sup.6 is selected from the group consisting of an unsubstituted alkylene group having from about 2 to about 4 carbon atoms and a substituted alkylene group having from about 2 to about 4 carbon atoms and containing a hydroxy group;
- X is an anion selected from the group consisting of a halogen, methyl sulfate, sulfate, and nitrate;
- n represents the valency of the anion represented by X;
- and,
- s is an integer equal to the number of said anions required to maintain electronic neutrality.
The method recited in claim 16 wherein said fines are selected from the group consisting of silica, iron minerals, alkaline earth metal carbonates and mixtures thereof.
Dependencies are inferred from the claim text.