US3687205A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Floating rig motion compensator
Assignee: Gulf Research and Development Co
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Filing: 1970-10-28
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Granted: 1972-08-29
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Expires: 1990-10-28
Abstract
Abstract Apparatus for compensating for the vertical motion of a floating rig caused by wave action to hold a tool at a constant depth in which the tool is suspended from a piston supported in a cylinder by a hydraulic fluid under pressure. The cylinder is hung from the traveling block of the rig whereby the cylinder moves vertically with the rig. A compensating cylinder mounted on the rig has a piston urged upwardly therein by compressed gas and limited in upward movement by a cable connected to the wellhead. A conduit connecting the two cylinders allows hydraulic fluid to be displaced from one cylinder to the other in response to waveinduced vertical motion of the drilling rig. A valve in the conduit allows slackening of the cable when the load supported by the piston is reduced.
Inventors
- 👤 Ernest A Mori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:35
CPC Classifications
E; E21; E21B; E21B19/00; E21B19/08; E21B19/09
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
188 words
In apparatus for suspending a tool in a well from a floating rig having a traveling block suspended therefrom, the improvement comprising a suspending cylinder supported by the traveling block, a suspending piston slidable in the suspending cylinder, said tool being suspended from the suspending piston and extending downwardly into the well, a compensating cylinder mounted on the rig, a compensating piston slidable in the compensating cylinder, connecting means extending downwardly from the compensating piston and connected to the marine floor for limiting upward movement of the compensating piston, means for supplying compressed gas into the compensating cylinder below the compensating piston to maintain the connecting means under tension and the compensating piston at its maximum elevation above the marine floor, an equalizing conduit extending from the compensating cylinder above the compensating piston to the suspending cylinder below the suspending piston, the effecTive cross-sectional area of the suspending cylinder below the suspending piston being equal to the cross-sectional area of the compensating cylinder above the compensating piston, and a hydraulic fluid in the suspending cylinder below the suspending piston and in the compensating cylinder above the compensating piston.
Claim 2
Dependent Claim
188 words
In apparatus for suspending a tool in a well from a floating rig having a traveling block suspended therefrom, the improvement comprising a suspending cylinder supported by the traveling block, a suspending piston slidable in the suspending cylinder, said tool being suspended from the suspending piston and extending downwardly into the well, a compensating cylinder mounted on the rig, a compensating piston slidable in the compensating cylinder, connecting means extending downwardly from the compensating piston and connected to the marine floor for limiting upward movement of the compensating piston, means for supplying compressed gas into the compensating cylinder below the compensating piston to maintain the connecting means under tension and the compensating piston at its maximum elevation above the marine floor, an equalizing conduit extending from the compensating cylinder above the compensating piston to the suspending cylinder below the suspending piston, the effecTive cross-sectional area of the suspending cylinder below the suspending piston being equal to the cross-sectional area of the compensating cylinder above the compensating piston, and a hydraulic fluid in the suspending cylinder below the suspending piston and in the compensating cylinder above the compensating piston.
Claim 3
Dependent Claim
24 words
Apparatus as set forth in claim 1 including means for supplying hydraulic fluid to the cylinders under pressure to maintain pressure in the cylinders.
Claim 4
Dependent Claim
19 words
Apparatus as set forth in claim 1 including a valve in the equalizing conduit to allow closing the conduit.
Claim 5
Dependent Claim
29 words
Apparatus as set forth in claim 3 including clamping means for preventing vertical movement of the tool relative to the floating rig, and means for elevating the suspending cylinder.
Claim 6
Dependent Claim
29 words
Apparatus as set forth in claim 3 in which the connecting means extending downwardly from the compensating cylinder is connected to the wellhead below the surface of the water.
Claim 7
Dependent Claim
30 words
Apparatus as set forth in claim 3 in which the floating rig is a drilling rig and the tool is drill pipe with a drill bit on its lower end.
Claim 8
Dependent Claim
48 words
Apparatus as set forth in claim 3 in which the means for supplying compressed gas comprise a gas accumulator having a volume 4 to 10 times the volume of the compensating cylinder and a conduit from the gas accumulator opening into the compensating cylinder below the compensating piston.
Claim 9
Dependent Claim
85 words
Apparatus as set forth in claim 3 including means for supplying hydraulic fluid to the cylinders to maintain the desired pressure in the cylinders, said means comprising a hydraulic fluid storage tank, a hydraulic fluid supply line from the storage tank to supply hydraulic fluid to the cylinders, a pump in the hydraulic fluid supply line, a recycle line connecting the hydraulic fluid supply line downstream of the pump with the hydraulic fluid supply storage tank, and a pressure regulating valve in the recycle line.
Claim 10
Dependent Claim
34 words
Apparatus as set forth in claim 8 in which the hydraulic fluid supply line opens into the compensating cylinder, and valve means in the hydraulic fluid supply line permit closing the line to flow.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |