Well drilling fluids
View Patent ↗Clay is stabilized in the drilling of wells and other formation treatment for hydrocarbon production by the addition to the drilling or other fluid of potassium formate together with a cationic formation control additive.
1. A composition of an aqueous drilling fluid comprising a cationic formation control additive and potassium formate, wherein the cationic formation control additive contains a homopolymer, a copolymer or an oligomer of an allyl ammonium compound with a chemical structure of [(CH 2 =CHCH 2 ) n N(CH 3 ) 4-n ][X], wherein X is an anion and n is 1, 2, 3 or 4, and wherein the cationic formation control additive and the potassium formate have a weight ratio with a range from about 75:25 to about 25:75.
2. The composition of claim 1 , wherein the anion is a halide.
3. The composition of claim 2 , wherein the anion is a chloride.
4. The composition of claim 3 , wherein n=2.
5. The composition of claim 1 , wherein the potassium formate is generated in situ from potassium hydroxide and formic acid.
6. The composition of claim 5 , wherein a combined concentration of the cationic formation control additive and the potassium formate is at least 0.001% by weight of the aqueous drilling fluid.
7. The composition of claim 1 , wherein the cationic formation control additive contains a copolymer of the allyl ammonium compound and a nitrogen-based compound selected from the group consisting of an acrylamide, a hydrolyzed acrylamide, derivatives thereof and combinations thereof.
8. The composition of claim 7 , wherein the copolymer contains up to about 65% by weight of the nitrogen-based compound.
9. The composition of claim 1 , wherein n=1.
10. The composition of claim 1 , wherein n=2.
11. The composition of claim 1 , wherein n=3.
12. The composition of claim 1 , wherein n=4.
13. The composition of claim 1 , wherein the anion is a formate.
14. The composition of claim 1 , further comprising a compound selected from the group consisting of a phosphonium compound, a sulfonium compound, derivatives thereof and combinations thereof.
15. A composition of an aqueous drilling fluid comprising potassium formate and a cationic formation control additive containing an allyl ammonium compound with a chemical structure of [(CH 2 =CHCH 2 ) n N(CH 3 ) 4-n ][X], wherein X is an anion and n is 1, 2, 3 or 4, and wherein the cationic formation control additive and the potassium formate have a weight ratio with a range from about 75:25 to about 25:75.
16. The composition of claim 15 , wherein the anion is a halide.
17. The composition of claim 16 , wherein the anion is a chloride.
18. The composition of claim 17 , wherein n=2.
19. The composition of claim 15 , wherein the anion is a formate.
20. The composition of claim 15 , wherein the potassium formate is generated in situ from potassium hydroxide and formic acid.
21. The composition of claim 15 , further comprising a compound selected from the group consisting of a phosphonium compound, a sulfonium compound, derivatives thereof and combinations thereof.
22. A composition of an aqueous drilling fluid comprising a formate salt and a cationic formation control additive, wherein the cationic formation control additive is a homopolymer of dimethyl diallyl ammonium chloride, and wherein the cationic formation control additive and the formate salt have a weight ratio with a range from about 75:25 to about 25:75.
23. The composition of claim 22 , wherein the formate salt is generated in situ from a hydroxide compound and formic acid.
24. The composition of claim 23 , wherein the hydroxide compound is potassium hydroxide.
25. The composition of claim 22 , wherein a combined concentration of the cationic formation control additive and the formate salt is at least 0.001% by weight of the aqueous drilling fluid.