US3637031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drilling fluid and method of rotary drilling therewith
Assignee: Standard Brands Chemical Industries Inc
•
Filing: 1969-12-12
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Granted: 1972-01-25
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Expires: 1989-12-12
Abstract
Abstract Polyacrylamide homopolymer, in which the ratio of pendant amide groups to pendant carboxylic acid or carboxylic acid salt groups is between 130 and 500, is effective as either a selective or nonselective flocculation agent to remove cutting fines from aqueous rotary drilling fluids.
Inventors
- 👤 Jerry D Hull
- 👤 Robert E Finch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:47
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
61 words
The process of claim 1, in which the cuttings removed from the borehole comprise both high and low yield solids and the water is treated with calcium ions prIor to addition of the acrylamide homopolymer to remove the adsorbed sodium ions from the high yield solids, upon which addition both high and low yield solids are nonselectively removed from the water.
Claim 2
Dependent Claim
40 words
The process of claim 2, in which, following removal of the low and high yield solids from the water, the calcium ions contained in the water are removed by chemical precipitation prior to recirculation of the water to the borehole.
Claim 3
Dependent Claim
55 words
A drilling fluid composition comprising water having dissolved therein from about 0.5 to about 5 lb. per 100 barrels of an acrylamide homopolymer having a molecular weight of from about 500,000 to about 10 million, the ratio of pendant amide moieties to pendant acid moieties in the homopolymer being from about 130 to about 500.
Claim 4
Dependent Claim
27 words
The drilling fluid composition of claim 4 in which the water contains dispersed therein from about 1 to about 6 percent by volume of sodium bentonitic clay.
Claim 5
Dependent Claim
21 words
The drilling fluid composition of claim 4 in which the water contains dissolved therein at least 150 p.p.m. of calcium ions.
Claim 6
Dependent Claim
144 words
In the process of oil well rotary drilling in which a low solids mud is used as a drilling fluid to cool the cutting bit and to carry cuttings from the borehole to the surface, whereupon finely divided particles of cuttings are removed from the water by means of flocculation and settling, the improvement which comprises adding to the low solids mud containing cuttings coming from the well a flocculating amount of an essentially nonhydrolyzed acrylamide homopolymer having an average molecular weight of from about 500,000 to about 10 million and in which the ratio of pendant amide moieties to pendant acid moieties is from about 130 to about 500 to flocculate selectively the low yield cuttings therefrom, settling out the thusly flocculated low yield solids and recirculating the low solids mud, from which the low yield solids have been removed, to the borehole.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |