Patent EP0500289A1 successfully refreshed from Google Patents.
US4015469A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pump-off monitor for rod pump wells
Assignee: Shell USA Inc
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Filing: 1976-07-02
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Granted: 1977-04-05
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Expires: 1996-07-02
Abstract
Abstract An improved method for determining when a rod pumped well has pumped-off wherein the energy input to the polished rod is determined for a portion of the pump stroke and the variation in the computed energy input between pump strokes is used as an indication of the well pumping-off.
Inventors
- 👤 Fred A. Womack
- 👤 Daniel F. Jahns
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:07
CPC Classifications
F; F04; F04B; F04B49/00; F04B49/02; E; E21; E21B; E21B47/00; E21B47/007; E21B47/008; E21B47/009
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
87 words
A method for monitoring a rod pumped well to determine when the well pumps-off by measuring the load on the rod and the displacement of the rod and then integrating the load versus displacement to obtain the energy input to the rod, the improvement comprising: integrating the load versus displacement measurements over an interval that extends equally in displacement on either side of the top of the pump stroke; and determining when the well pumps-off by comparing the integrated values to detect when the integrated value decreases.
Claim 2
Independent Claim
87 words
A method for monitoring a rod pumped well to determine when the well pumps-off by measuring the load on the rod and the displacement of the rod and then integrating the load versus displacement to obtain the energy input to the rod, the improvement comprising: integrating the load versus displacement measurements over an interval that extends equally in displacement on either side of the top of the pump stroke; and determining when the well pumps-off by comparing the integrated values to detect when the integrated value decreases.
Claim 3
Dependent Claim
34 words
The method of claim 1 and in addition, determining when the well pumps-off by comparing said integrated value with the average value of plurality of previously obtained maximum values of the integration previously obtained.
References Cited (Backward Citations)
US2107151A
Cited
US2767578A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |