US3688845A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Well cementing method employing an oil base preflush
Assignee: Mobil Oil AS
•
Filing: 1971-03-08
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Granted: 1972-09-05
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Expires: 1991-03-08
Abstract
Abstract This specification discloses a method of cementing casing in a well having an oil base drilling mud therein. A preflush solution comprised of an oil and a dispersant, which preflush solution has a lower viscosity and a lower gel strength than the drilling mud in the well, is flowed through the annular space between casing positioned in the well and the well of the well. Thereafter, a cement slurry is flowed into the annular space and allowed to set.
Inventors
- 👤 Joseph U Messenger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:55
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/42; C09K8/424
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
21 words
The method of claim 1 wherein said oil is selected from the group consisting of kerosene, diesel oil, and mixtures thereof.
Claim 2
Dependent Claim
23 words
The method of claim 1 wherein the volume of said slug of preflush solution is within the range of 10 to 50 barrels.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein said dispersing agent is lecithin.
Claim 4
Dependent Claim
25 words
The method of claim 4 wherein the amount of lecithin in said preflush solution is 1 to 5 pounds per barrel of said preflush solution.
Claim 5
Dependent Claim
42 words
The method of claim 1 further comprising, subsequent to step (a) and prior to step (b), flowing a slug of an aqueous solution having a water wetting surfactant therein into said annular space between said casing the the wall of said well.
Claim 6
Dependent Claim
71 words
The method of claim 6 wherein said slug of an aqueous solution is injected in an amount within the range of 5 to 50 barrels and contains therein 1/2 to 10 pounds per barrel of a polyoxyethylene-aryl ether of the structural formula: wherein: R is a hydrogen atom or an aliphatic substituent having no more than nine carbon atoms, and n is an integer within the range of 10 to 100.
Claim 7
Independent Claim
120 words
A method of cementing casing in a well penetrating a subterranean formation, said well having an oil base drilling mud therein, comprising: a. flowing a slug of preflush solution comprised of an oil, a dispersing agent, a viscosifier, and a weighting material, said solution having a lower viscosity and lower gel strength than said drilling mud and having a critical turbulence pump rate of no greater than three barrels per minute, into the annular space between said casing and the wall of said well; b. flowing through said annular space and emplacing therein a cement slurry; and c. allowing said cement slurry to set and form an impermeable cement sheath which bonds said casing to said wall of said well.
Claim 8
Dependent Claim
23 words
The method of claim 8 wherein the volume of said slug of preflush solution is within the range of five to 50 barrels.
Claim 9
Dependent Claim
21 words
The method of claim 9 wherein said oil is selected from the group consisting of diesel oil, kerosene, and mixtures thereof.
Claim 10
Dependent Claim
11 words
The method of claim 10 wherein said dispersing agent is lecithin.
Claim 11
Dependent Claim
13 words
The method of claim 11 wherein said viscosifier is an amine substituted bentonite.
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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) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |