US4347899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Downhold injection of well-treating chemical during production by gas lift
Assignee: Mobil Oil AS
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Filing: 1981-05-28
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Granted: 1982-09-07
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Expires: 2001-05-28
Abstract
Abstract A liquid well-treating chemical composition is injected into the production tubing during gas lift operations by providing a differential pressure operated valve downhole from the lowermost gas lift flow valve and maintaining sufficient liquid head of the chemical composition in the annulus to open the valve and cause the liquid chemical composition to pass into the interior of the production tubing.
Inventors
- 👤 Robert F. Weeter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:22
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/12; E21B43/121; E21B43/122; E21B43/123; E21B41/00; E21B41/02; Y; Y10; Y10S; Y10S166/00; Y10S166/902
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
200 words
In the production of oil from an oil well by gas lift operations of the type wherein (1) recovery gas is introduced into the annular space between a well casing and a tubing string located within said casing, said tubing string provided with at least one gas lift flow valve intermediate the well head and the wellbore bottom, and (2) gas pressure in the annular space is maintained at a level effective to cause the flow valve to open whereby the recovery gas causes oil to be produced at the well head, the improvement which comprises: (a) providing a liquid well-treating chemical composition injection valve on said tubing string downhole from the lowermost gas lift flow valve, said well-treating composition injection valve being operatively opened by the pressure difference between the annular space and the tubing string at the location of the well-treating composition injection valve, and (b) during the oil production of step (2), injecting into the annular space a well-treating effective amount of a liquid, well-treating chemical composition said composition providing a liquid head in the annular space effective to cause the well-treating composition injection valve to open and the well-treating composition to pass into the tubing string.
Claim 2
Dependent Claim
200 words
In the production of oil from an oil well by gas lift operations of the type wherein (1) recovery gas is introduced into the annular space between a well casing and a tubing string located within said casing, said tubing string provided with at least one gas lift flow valve intermediate the well head and the wellbore bottom, and (2) gas pressure in the annular space is maintained at a level effective to cause the flow valve to open whereby the recovery gas causes oil to be produced at the well head, the improvement which comprises: (a) providing a liquid well-treating chemical composition injection valve on said tubing string downhole from the lowermost gas lift flow valve, said well-treating composition injection valve being operatively opened by the pressure difference between the annular space and the tubing string at the location of the well-treating composition injection valve, and (b) during the oil production of step (2), injecting into the annular space a well-treating effective amount of a liquid, well-treating chemical composition said composition providing a liquid head in the annular space effective to cause the well-treating composition injection valve to open and the well-treating composition to pass into the tubing string.
Claim 3
Dependent Claim
20 words
A process in accordance with claim 1 wherein the well-treating composition injection valve is located adjacent to the wellbore bottom.
Claim 4
Dependent Claim
17 words
A process in accordance with claim 1 wherein the well-treating composition is added to the recovery gas.
Claim 5
Dependent Claim
31 words
A process in accordance with claim 1 wherein the upper surface of the liquid head of the well-treating composition is maintained below the location of the lowermost gas lift flow valve.
Claim 6
Dependent Claim
29 words
A process according to claim 1 wherein the liquid well-treating chemical composition comprises a corrosion inhibitor, a paraffin control solvent or a scale control chemical as the active ingredient.
Claim 7
Dependent Claim
19 words
A process according to claim 5 wherein the liquid well-treating composition comprises a corrosion inhibitor and a liquid carrier.
Claim 8
Dependent Claim
26 words
A process in accordance with claim 6 wherein the liquid carrier has a vapor pressure effective to substantially prevent vaporization of said carrier under downhole conditions.
Claim 9
Dependent Claim
27 words
A process in accordance with claim 6 wherein the corrosion inhibitor has a vapor pressure effective to substantially prevent vaporization of said corrosion inhibitor under downhole conditions.
Claim 10
Dependent Claim
16 words
A process according to claim 5 wherein the liquid well-treating composition comprises a paraffin control solvent.
Claim 11
Dependent Claim
28 words
A process according to claim 9 wherein the paraffin control solvent has a vapor pressure effective to substantially prevent vaporization of said paraffin control solvent under downhole conditions.
Claim 12
Dependent Claim
20 words
A process according to claim 5 wherein the liquid well-treating composition comprises a scale control chemical and a liquid carrier.
Claim 13
Dependent Claim
28 words
A process according to claim 11 wherein the scale control chemical has a vapor pressure effective to substantially prevent vaporization of said scale control chemical under downhole conditions.
Claim 14
Dependent Claim
26 words
A process according to claim 11 wherein the liquid carrier has a vapor pressure effective to substantially prevent vaporization of said liquid carrier under downhole conditions.
Claim 15
Dependent Claim
27 words
A process according to claim 1 wherein the liquid well-treating chemical composition has a vapor pressure effective to substantially prevent vaporization of said composition under downhole conditions.
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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) | 1985-09-06 | 1986-03-08 | 1986-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-06 | 1990-03-08 | 1990-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-06 | 1994-03-08 | 1994-09-07 | $7700.00 | Window Closed / Lapsed |