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US4046197A Expired / Lapsed US ⏱️ 0.0 years remaining

Well completion and workover method

Assignee: ExxonMobil Upstream Research Co
•
Filing: 1976-05-03
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Granted: 1977-09-06
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Expires: 1996-05-03
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Abstract

Abstract A well completion and workover method wherein a subterranean formation is contacted with a high density, nondamaging treating fluid which comprises a saturated, aqueous solution having finely divided particles of a water soluble salt suspended therein. The saturated aqueous saline solution should have a density of at least about 1.2 g/cc and the suspended salt particles should be present in sufficient quantities to substantially increase the overall density of the treating solution. The preferred fluid comprises a suspension of pulverized sodium chloride in a saturated calcium chloride solution. Dispersants and viscosifiers can be added in minor amounts to help maintain the salt particles in suspension.

Inventors

  • 👤 Clay Gruesbeck, Jr.
  • 👤 Walter L. Penberthy, Jr.
  • 👤 Thomas W. Muecke

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 14:22
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/02; E21B43/04; C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/06; C09K8/08; C09K8/14; C09K8/16; Y; Y10; Y10S; Y10S507/00; Y10S507/925

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 89 words
In a well completion and workover method wherein a subterranean formation is contacted with a treating fluid, the improvement wherein said treating fluid comprises a saturated aqueous saline solution having a density of at least about 1.2 g/cc at 10° C. and having finely divided particles of a water soluble salt suspended therein, said particles of salt being present in sufficient quantities to substantially increase the density of said treating fluid, and minor amounts of xanthomonas gum and a polyphosphate acid ester to prevent settling of said salt particles.
Claim 2
Dependent Claim 89 words
In a well completion and workover method wherein a subterranean formation is contacted with a treating fluid, the improvement wherein said treating fluid comprises a saturated aqueous saline solution having a density of at least about 1.2 g/cc at 10° C. and having finely divided particles of a water soluble salt suspended therein, said particles of salt being present in sufficient quantities to substantially increase the density of said treating fluid, and minor amounts of xanthomonas gum and a polyphosphate acid ester to prevent settling of said salt particles.
Claim 3
Dependent Claim 41 words
The well completion and workover method defined in claim 1 wherein said saturated aqueous saline solution is selected from the group consisting of saturated aqueous solutions of sodium chloride, calcium chloride, calcium bromide, calcium nitrate, and zinc chloride and mixtures thereof.
Claim 4
Dependent Claim 18 words
The well completion and workover method defined in claim 1 wherein said water soluble salt is sodium chloride.
Claim 5
Dependent Claim 27 words
The well completion and workover method defined in claim 1 wherein substantially all of said finely divided salt particles have a particle size of under 25 microns.
Claim 6
Dependent Claim 78 words
In a well completion and workover method wherein a subterranean formation is contacted with a treating fluid, the improvment wherein said treating fluid comprises a saturated aqueous solution of calcium chloride having finely divided particles of sodium chloride suspended therein, said particles of sodium chloride being added in sufficient quantities to substantially increase the density of said treating fluid, and minor amounts of xanthomonas gum and a polyphosphate acid ester to prevent settling of said sodium chloride particles.
Claim 7
Dependent Claim 78 words
In a well completion and workover method wherein a subterranean formation is contacted with a treating fluid, the improvment wherein said treating fluid comprises a saturated aqueous solution of calcium chloride having finely divided particles of sodium chloride suspended therein, said particles of sodium chloride being added in sufficient quantities to substantially increase the density of said treating fluid, and minor amounts of xanthomonas gum and a polyphosphate acid ester to prevent settling of said sodium chloride particles.
Claim 8
Dependent Claim 35 words
The well completion and workover method defined in claim 5 wherein said xanthomonas gum and said polyphosphate acid ester are in a weight ratio of from about 1 to 5 to about 1 to 1.
Claim 9
Dependent Claim 95 words
In a well completion method wherein a drilling fluid is circulated through a drill string and contacted with a subterranean formation, the improvement wherein said drilling fluid comprises a saturated aqueous saline solution having a density of at least about 1.2 g/cc at 10° C. and having finely divided particles of a water soluble salt suspended therein, and minor amounts of xanthomonas gum and a polyphosphate acid ester to prevent settling of said salt particles, said drilling fluid having sufficient density to provide a hydrostatic head capable of preventing influx of fluids from said formation.
Claim 10
Dependent Claim 95 words
In a well completion method wherein a drilling fluid is circulated through a drill string and contacted with a subterranean formation, the improvement wherein said drilling fluid comprises a saturated aqueous saline solution having a density of at least about 1.2 g/cc at 10° C. and having finely divided particles of a water soluble salt suspended therein, and minor amounts of xanthomonas gum and a polyphosphate acid ester to prevent settling of said salt particles, said drilling fluid having sufficient density to provide a hydrostatic head capable of preventing influx of fluids from said formation.
Claim 11
Dependent Claim 100 words
In a workover method wherein a subterranean hydrocarbon bearing formation is contacted with a nondamaging well treatment fluid, the improvement wherein said nondamaging well treatment fluid comprises a saturated aqueous saline solution having a density of at least about 1.2 g/cc at 10° C. and having finely divided particles of a water soluble salt suspended therein, and minor amounts of xanthomonas gum and a polyphosphate acid ester to prevent settling of said salt particles, said well treatment fluid having sufficient density to provide a wellbore pressure at least about 100 pounds per square inch above the pressure of said formation.
Claim 12
Dependent Claim 100 words
In a workover method wherein a subterranean hydrocarbon bearing formation is contacted with a nondamaging well treatment fluid, the improvement wherein said nondamaging well treatment fluid comprises a saturated aqueous saline solution having a density of at least about 1.2 g/cc at 10° C. and having finely divided particles of a water soluble salt suspended therein, and minor amounts of xanthomonas gum and a polyphosphate acid ester to prevent settling of said salt particles, said well treatment fluid having sufficient density to provide a wellbore pressure at least about 100 pounds per square inch above the pressure of said formation.
Claim 13
Dependent Claim 35 words
The workover method defined in claim 8 wherein the particles of salt which remain in said formation after the well treatment fluid is withdrawn are removed by contacting said particles with an unsaturated aqueous solution.
Claim 14
Dependent Claim 19 words
The workover method defined in claim 9 wherein said unsaturated aqueous solution is field brine produced from said formation.
Claim 15
Dependent Claim 17 words
The workover method defined in claim 9 wherein said unsaturated aqueous solution is injected into said formation.

References Cited (Backward Citations)

US1819646A Cited
US2352805A Cited
US3378489A Cited
US3633689A Cited
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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) 1980-09-05 1981-03-07 1981-09-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-09-05 1985-03-07 1985-09-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-09-05 1989-03-07 1989-09-06 $7700.00 Window Closed / Lapsed

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