US3792902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preventing plugging of solution mining wells
Assignee: Shell USA Inc
•
Filing: 1972-08-14
•
Granted: 1974-02-19
•
Expires: 1992-08-14
Abstract
Abstract Plugging of solution-mining wells by mineral precipitation due to solubility changes associated with temperature and pressure changes of the solution-mining liquid is prevented by injecting a diluent into the well production tubing, or into an area surrounding the production tubing intake.
Inventors
- 👤 L Towell
- 👤 J Brew
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:05
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/28; E21B43/281
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
129 words
The method of claim 1 wherein the well is cased with a tubular casing and said bicarbonate-containing solution is lifted through a production tubing string within the casing and including the steps of: positioning pack-off means in the space between the casing and the production tubing at a point above the inlet of said bicarbonate-containing solution into the production tubing; providing pressure-responsive flow control means in the production tubing string above the pack-off means for admitting water into the production tubing from the space surrounding the production tubing; injecting water into the well through the space between the production tubing and the casing; and adjusting the rate at which water flows through the pressure-responsive flow control means by adjusting pressure in the space between the production tubing and casing.
Claim 2
Dependent Claim
39 words
The method of claim 1 which includes, prior to mixing, the step of heating the water to a temperature at least as high as the temperature of said bicarbonate-containing aqueous solution with which the water is to be mixed.
Claim 3
Dependent Claim
97 words
In a method for recovering nahcolite and hydrocarbons from a subsurface, nahcolite-containing oil-shale formation of the type wherein the oil-shale is permeabilized by injecting an aqueous nahcolite solvent into contact with the formation at a temperature sufficient to thermally fracture the oil shale and wherein hot nahcolite-containing nahcolite solvent is withdrawn from the formation through a well production tubing string, the improvement comprising: injecting water into the lower portion of the production tubing string at a temperature high enough to prevent bicarbonate deposition in the well but lower than a maximum temperature at which carbonate precipitation occurs.
Claim 4
Dependent Claim
15 words
The method of claim 4 wherein the water contains substantially no calcium or magnesium ions.
References Cited (Backward Citations)
US3523582A
Cited
US3700280A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |