Clay control additive for wellbore fluids
AssigneeInnovative Chemical Technologies Canada Ltd.
InventorsClayton Smith, Darin Oswald, Michael D. Daffin
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Abstract
A clay stabilizer which is capable of inhibiting swelling in a wide variety of clay types and is also capable of restoring permeability in formations which have previously been damaged by clay swelling. Amine salts of differing molecular weights configurations and ionic strength are combined to provide transport into micropores, mesopores and macropores in the formation and to effect cationic change therein. A poly quaternary amine having a high to very high charge density is added along with lower molecular weight amine salts to substantially permanently exchange cations with the clay in the formation.
Claims21
A method for treating a formation having a mixture of two or more clay types comprising:
- providing a clay stabilizer comprising a combination of
- two or more amine salts capable of cation exchange with the two or more clay types within the formation, each of the two or more amine salts having a different molecular weight and charge density relative to each of the other of the two or more amine salts so as to permit transport into different sized pore spaces within the formation for reducing clay swelling therein,
- wherein one of the two or more amine salts is a protonated amine in a range of C1 to about C18 having from one to about seven available amine groups;
- and
- wherein one of the two or more amine salts is a long chain poly quaternary amine having a molecular weight less than about 5000 atomic mass units and having greater than about 200 quaternized nitrogen atoms;
- and
- the balance being water;
- and
- exposing the formation having the mixture of two or more clay types to the clay stabilizer.
A method for treating a formation having a mixture of two or more clay types comprising:
- providing a clay stabilizer comprising a combination of
- two or more amine salts capable of cation exchange with the two or more clay types within the formation, each of the two or more amine salts having a different molecular weight and charge density relative to each of the other of the two or more amine salts so as to permit transport into different sized pore spaces within the formation for reducing clay swelling therein,
- wherein one of the two or more amine salts is a protonated amine having a molecular weight sufficient to permit transport into mesopores in the formation;
- and
- wherein one of the two or more amine salts is a long chain poly quaternary amine having a molecular weight less than about 5000 atomic mass units and having greater than about 200 quaternized nitrogen atoms so as to provide transport into and cation exchange within the large pore spaces in the formation and
- the balance being water;
- and
- exposing the formation having the mixture of two or more clay types to the clay stabilizer.
Dependencies are inferred from the claim text.