Hydrocarbon recovery
View Patent ↗Low concentrations, 1–10% of potassium salt, especially potassium formate, are used in a drilling fluid in oil production. Preferably they are used with guar derivatives, most preferably carboxymethyl hydroxypropyl guar. The concentration of potassium formate is maintained at the desired level by adjusting the potassium formate to maintain a desired Zeta potential in the circulating drilling fluid. The potassium formate/guar derivative composition may be used in the substantial absence of hydrophilic clay additive.
1. A method for treating a hydrocarbon producing formation to stabilize shale and clay therein, comprising:
contacting the hydrocarbon producing formation with a treatment fluid containing a potassium formate concentration by weight within a range from about 1% to about 10%;
determining a first Zeta potential of the treatment fluid; and
adjusting the potassium formate concentration to maintain the treatment fluid within a Zeta potential of about −15 mV or less.
2. The method of claim 1 , wherein the treatment fluid includes a viscosifying amount of a polygalactomannan.
3. The method of claim 2 , wherein the polygalactomannan comprises a guar compound.
4. The method of claim 3 , wherein the guar compound comprises a carboxymethyl hydroxypropyl guar compound or derivative thereof.
5. The method of claim 1 , wherein the potassium formate concentration is within a range from about 2% to about 6%.
6. The method of claim 5 , wherein the treatment fluid further comprises a carboxymethyl hydroxypropyl guar compound at a concentration within a range from about 0.1% to about 1% by weight of the treatment fluid.
7. The method of claim 6 , wherein the treatment fluid further comprises calcium carbonate.
8. The method of claim 1 , further comprising intermittently measuring the Zeta potential of the treatment fluid during treatment of the formation.
9. The method of claim 1 , wherein the Zeta potential is about −18 mV or less.
10. The method of claim 9 , wherein the Zeta potential is about −21 mV or less.
11. The method of claim 10 , wherein the Zeta potential is about −25 mV or less.
12. A method for treating a hydrocarbon producing formation to stabilize shale and clay therein, comprising:
contacting the hydrocarbon producing formation with a treatment fluid containing potassium formate at a concentration by weight of about 10% or less and a capillary suction time of about 70 seconds or less; and
adjusting the concentration of the potassium formate to maintain the treatment fluid within a Zeta potential of about −15 mV or less.
13. The method of claim 12 , wherein the treatment fluid includes a viscosifying amount of a guar compound.
14. The method of claim 13 , wherein the guar compound has a concentration by weight of the treatment fluid within a range from about 0.01% to about 1.2%.
15. The method of claim 14 , wherein the guar compound comprises a carboxymethyl hydroxypropyl guar compound or derivative thereof.
16. The method of claim 12 , wherein the treatment fluid further comprises calcium carbonate.
17. The method of claim 12 , wherein the treatment fluid comprises a drilling fluid.
18. The method of claim 17 , further comprising collecting at least one sample slurry of shale or clay particulates from the drilling fluid.
19. The method of claim 18 , further comprising determining a first Zeta potential of the at least one sample slurry and adjusting the potassium formate concentration to maintain the drilling fluid within a predetermined Zeta potential range.
20. The method of claim 19 , further comprising recirculating the drilling fluid.
21. The method of claim 12 , further comprising intermittently measuring the Zeta potential of the treatment fluid during treatment of the formation.
22. The method of claim 12 , wherein the concentration of the potassium formate is about 1.1% or less and the capillary suction time is about 26.6 seconds or less.
23. The method of claim 22 , wherein the Zeta potential is about −22 mV or less.
24. The method of claim 23 , wherein the concentration of the potassium formate is about 0.3% or less and the capillary suction time is about 21.1 seconds or less.
25. The method of claim 24 , wherein the Zeta potential is about −27.2 mV or less.
26. The method of claim 12 , wherein the Zeta potential is about −18 mV or less.
27. The method of claim 26 , wherein the Zeta potential is about −21 mV or less.
28. The method of claim 27 , wherein the Zeta potential is about −25 mV or less.
29. The method of claim 28 , wherein the Zeta potential is about −29 mV or less.
30. The method of claim 29 , wherein the Zeta potential is about −33 mV or less.
31. A method for treating a hydrocarbon producing formation to stabilize shale and clay therein, comprising:
contacting the hydrocarbon producing formation with a treatment fluid containing potassium formate at a concentration by weight of about 10% or less and a capillary suction time of about 70 seconds or less;
determining a first Zeta potential of the treatment fluid; and
adjusting the concentration of the potassium formate to maintain the treatment fluid within a desired Zeta potential range.
32. The method of claim 31 , further comprising maintaining a Zeta potential at about −15 mV or less.
33. The method of claim 32 , wherein the Zeta potential is about −18 mV or less.
34. The method of claim 33 , wherein the Zeta potential is about −21 mV or less.
35. The method of claim 34 , wherein the Zeta potential is about −25 mV or less.
36. The method of claim 31 , wherein the treatment fluid includes a viscosifying amount of a guar compound.
37. The method of claim 36 , wherein the guar compound has a concentration by weight of the treatment fluid within a range from about 0.01% to about 1.2%.
38. The method of claim 37 , wherein the guar compound comprises a carboxymethyl hydroxypropyl guar compound or derivative thereof.
39. A method for treating a hydrocarbon producing formation to stabilize shale and clay therein, comprising:
contacting the hydrocarbon producing formation with a treatment fluid containing potassium formate at a concentration by weight within a range from about 2% to about 6%;
determining a first Zeta potential of the treatment fluid; and
adjusting the concentration of the potassium formate to maintain a Zeta potential of the treatment fluid at about −15 mV or less.
40. The method of claim 39 , wherein the Zeta potential is about −18 mV or less.
41. The method of claim 40 , wherein the Zeta potential is about −21 mV or less.
42. The method of claim 41 , wherein the Zeta potential is about −25 mV or less.