US3986964A
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US
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Method of well drilling and composition therefor
Assignee: TEXAS UNITED CHEMICAL Corp A CORP OF TX
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Filing: 1973-06-11
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Granted: 1976-10-19
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Expires: 1993-06-11
Abstract
Abstract A non-damaging well drilling fluid contains a polysaccharide, a lignosulfonate, chrome sulfate, a pH modifier and, preferably, graded calcium carbonate and starch. The fluid is effective to seal off the well bore essentially immediately and is non-damaging in that it causes little permanent plugging of the formation by loss of the drilling fluid solids to the formation.
Inventors
- 👤 Cecil M. Smithey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:59
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/003; C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/20; C09K8/203
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
174 words
Method of drilling a well in an underground formation which comprises circulating in said well, while drilling, a non-damaging aqueous drilling fluid consisting essentially of a. a polysaccharide obtained by the action of bacteria of the genus Xanthomonas on a carbohydrate, said polysaccharide being substantially non-cross-linked and the amount thereof being about 1/4 to 4 pounds per barrel of said solution, b. a lignosulfonate in an amount of about 1/2 to 5 pounds per barrel, c. chrome sulfate in an amount of about 0.02 to 0.5 pounds per barrel, the amount of chrome being less than 4% by weight of the chrome sulfate and lignosulfonate, d. a basic metal compound in an amount to yield a solution pH of at least 7, e. calcium carbonate in an amount of 1/2 to 75 pounds per barrel, said calcium carbonate being graded such that at least about 10% of the particles are contained in each of the first 10%, beginning with zero, of the size range, the next 15%, the next 25% and the next 50%.
Claim 2
Dependent Claim
174 words
Method of drilling a well in an underground formation which comprises circulating in said well, while drilling, a non-damaging aqueous drilling fluid consisting essentially of a. a polysaccharide obtained by the action of bacteria of the genus Xanthomonas on a carbohydrate, said polysaccharide being substantially non-cross-linked and the amount thereof being about 1/4 to 4 pounds per barrel of said solution, b. a lignosulfonate in an amount of about 1/2 to 5 pounds per barrel, c. chrome sulfate in an amount of about 0.02 to 0.5 pounds per barrel, the amount of chrome being less than 4% by weight of the chrome sulfate and lignosulfonate, d. a basic metal compound in an amount to yield a solution pH of at least 7, e. calcium carbonate in an amount of 1/2 to 75 pounds per barrel, said calcium carbonate being graded such that at least about 10% of the particles are contained in each of the first 10%, beginning with zero, of the size range, the next 15%, the next 25% and the next 50%.
Claim 3
Dependent Claim
43 words
Method according to claim 1 wherein the amounts of ingredients (a), (b), (c) and (e) are about 1/4 to 4 pounds per barrel, 1.1 to 4 pounds per barrel, 0.05 to 0.5 pounds per barrel and 1/2 to 50 pounds per barrel respectively.
Claim 4
Dependent Claim
34 words
Method according to claim 1 wherein the amounts of ingredients (a), (b), (c) and (e) are about 1/2 to 3, 2, 0.1 to 0.3 and 3/4 to 50 respectively and in pounds per barrel.
Claim 5
Dependent Claim
22 words
Method according to claim 1 wherein the aqueous solution also contains starch in the amount of 0.1 to 5 pounds per barrel.
Claim 6
Dependent Claim
48 words
Method according to claim 1 wherein said aqueous solution achieves, in the standard core permeability test, essentially complete seal off in less than five pore volumes of solution and on backflush without acidizing at least 70% of the initial permeability in less than 25 pore volumes of solution.
Claim 7
Dependent Claim
122 words
Method of drilling an underground well which comprises circulating in the well, while drilling, a non-damaging aqueous drilling fluid consisting essentially of 1-15 pounds per barrel of fluid of a mixture of about 0.02 to 5 pounds per barrel of each of the following a. a substatially non-crosslinked polysaccharide produced by the action of the genus Xanthomanas on a carbohydrate, b. a lignosulfonate, c. a chrome sulfate, the amount of lignosulfonate and chrome sulfate being such that the viscosity of said mixture is not substantially different than an aqueous solution containing the same pounds per barrel of said polysaccharide as in said mixture, wherein the amount of chromium is less than 4% based on the total weight of chrome sulfate and lignosulfonate.
Claim 8
Dependent Claim
122 words
Method of drilling an underground well which comprises circulating in the well, while drilling, a non-damaging aqueous drilling fluid consisting essentially of 1-15 pounds per barrel of fluid of a mixture of about 0.02 to 5 pounds per barrel of each of the following a. a substatially non-crosslinked polysaccharide produced by the action of the genus Xanthomanas on a carbohydrate, b. a lignosulfonate, c. a chrome sulfate, the amount of lignosulfonate and chrome sulfate being such that the viscosity of said mixture is not substantially different than an aqueous solution containing the same pounds per barrel of said polysaccharide as in said mixture, wherein the amount of chromium is less than 4% based on the total weight of chrome sulfate and lignosulfonate.
Claim 9
Dependent Claim
24 words
Method according to claim 6 wherein the amount of chromium is less than 2.5% based on the total weight of chrome sulfate and lignosulfonate.
Claim 10
Dependent Claim
31 words
Method according to claim 6 wherein the amount of (a), (b) and (c) is about, respectively and in pounds per barrel of fluid; 1/2 to 3, 2, and 0.1 to 0.3.
Claim 11
Dependent Claim
46 words
Method according to claim 6 wherein said fluid, in the standard core permeability test, exhibits essentially complete seal off in less than 5 pore volumes of fluid and, on backflush, regains at least 70% of the initial permeability in less than 25 pore volumes of fluid.
Claim 12
Dependent Claim
34 words
Method according to claim 9 wherein the amount of (a), (b) and (c) is, respectively, 1/4 to 4 pounds per barrel, 1/2 to 5 pounds per barrel and 0.02 to 0.5 pounds per barrel.
Claim 13
Dependent Claim
30 words
Method according to claim 9 wherein the amount of (a), (b) and (c) is about, respectively: 1/2 to 3 pounds per barrel, 2, and 0.1 to 0.3 pounds per barrel.
Claim 14
Dependent Claim
31 words
Method according to claim 9 wherein said seal off occurs in about one pore volume and said regaining is at least 65% in less than about 15 pore volumes of fluid.
Claim 15
Dependent Claim
17 words
Method according to claim 12 wherein on backflush said fluid regains about 90% of the initial permeability.
Claim 16
Dependent Claim
29 words
Method according to claim 7 wherein said fluid also contains graded calcium carbonate in an amount effective to reduce the pore volumes of fluid required to achieve seal off.
Claim 17
Dependent Claim
47 words
Method according to claim 14 wherein the calcium carbonate particle size is distributed so that at least about 10% of the particles are contained in each of the first 10%, beginning with zero, of the size range, the next 15%, the next 25% and the next 50%.
Claim 18
Dependent Claim
20 words
Method according to claim 14 wherein said fluid also contains 0.1 to 5 pounds per barrel of fluid of starch.
Claim 19
Dependent Claim
136 words
Method of drilling an underground well which comprises circulating in the well, while drilling, a non-damaging drilling fluid consisting essentially of 1- 15 pounds per barrel of fluid of a mixture of about 0.02 to 5 pounds per barrel of each of the following a. a substantially non-crosslinked polysaccharide produced by the action of the genus Xanthomanas on a carbohydrate, b. a lignosulfonate, c. a chromium sulfate, the amount of lignosulfonate and chromium sulfate being such that the viscosity of said mixture is not substantially different than an aqueous solution containing the same pounds per barrel of said polysaccharide as in said mixture wherein the amount of chromium is less than 4% based on the total weight of the chrome sulfate and liqnosulfonate and wherein said chromium sulfate is at least partially reacted with the lignosulfonate.
Claim 20
Dependent Claim
136 words
Method of drilling an underground well which comprises circulating in the well, while drilling, a non-damaging drilling fluid consisting essentially of 1- 15 pounds per barrel of fluid of a mixture of about 0.02 to 5 pounds per barrel of each of the following a. a substantially non-crosslinked polysaccharide produced by the action of the genus Xanthomanas on a carbohydrate, b. a lignosulfonate, c. a chromium sulfate, the amount of lignosulfonate and chromium sulfate being such that the viscosity of said mixture is not substantially different than an aqueous solution containing the same pounds per barrel of said polysaccharide as in said mixture wherein the amount of chromium is less than 4% based on the total weight of the chrome sulfate and liqnosulfonate and wherein said chromium sulfate is at least partially reacted with the lignosulfonate.
Claim 21
Dependent Claim
24 words
Method according to claim 17 wherein the amount of chromium is less than 2.5% based on the total weight of chromium sulfate and lignosulfonate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-19 | 1980-04-19 | 1980-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-19 | 1984-04-19 | 1984-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-19 | 1988-04-19 | 1988-10-19 | $7700.00 | Window Closed / Lapsed |