US3693732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling pressure in a well
Assignee: Edwards Engineering Corp
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Filing: 1970-10-15
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Granted: 1972-09-26
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Expires: 1990-10-15
Abstract
Abstract This disclosure is directed to a system for controlling pressure in a well bore having a drill string through which a drilling fluid is directed. A balanced piston well choke is disposed in the drilling fluid return line which is automatically responsive to varying flow rates of the return drilling fluid in a manner to maintain a substantially constant back pressure on the return drilling fluid.
Inventors
- 👤 Nestor Sabi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:55
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/08; E21B34/00; E21B34/02; E21B34/025
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
221 words
In a system for controlling pressure in a well bore having a drill string through which a drilling fluid is directed, the combination comprising: means for circulating a drilling fluid through said drill string, a return line connected in communication with said well bore for receiving the return drilling fluid from said well bore, a valve means disposed in said return line which is automatically responsive to variations in flow of said return drilling fluid through said return line, and means for maintaining a substantially constant back pressure on said valve means, said valve means including a valve housing having an inlet and an outlet, said inlet being connected to said return line, and said outlet adapted to connect to a mud tank, means defining an orifice in said outlet, a valving member for valving said orifice which is rendered responsive to the rate of flow of said returning drill fluid, and means operatively associated with said valving member for maintaining a predetermined back pressure thereon, said back pressure producing means including a fluid pressure cylinder connected to the valve housing, a piston disposed within said cylinder, said piston being directly connected to said valving member so as to be rendered responsive to the movement of said valving member, and means for imposing a substantially constant back pressure on said piston.
Claim 2
Dependent Claim
221 words
In a system for controlling pressure in a well bore having a drill string through which a drilling fluid is directed, the combination comprising: means for circulating a drilling fluid through said drill string, a return line connected in communication with said well bore for receiving the return drilling fluid from said well bore, a valve means disposed in said return line which is automatically responsive to variations in flow of said return drilling fluid through said return line, and means for maintaining a substantially constant back pressure on said valve means, said valve means including a valve housing having an inlet and an outlet, said inlet being connected to said return line, and said outlet adapted to connect to a mud tank, means defining an orifice in said outlet, a valving member for valving said orifice which is rendered responsive to the rate of flow of said returning drill fluid, and means operatively associated with said valving member for maintaining a predetermined back pressure thereon, said back pressure producing means including a fluid pressure cylinder connected to the valve housing, a piston disposed within said cylinder, said piston being directly connected to said valving member so as to be rendered responsive to the movement of said valving member, and means for imposing a substantially constant back pressure on said piston.
Claim 3
Dependent Claim
28 words
The invention as defined in claim 1 wherein said latter means including an accumulator for containing a supply of fluid for exerting said fluid pressure on said piston.
Claim 4
Dependent Claim
17 words
The invention as defined in claim 2 and including means for maintaining a pressure on said fluid.
Claim 5
Dependent Claim
18 words
The invention as defined in claim 1 wherein said valve head and said piston have substantially equal diameters.
Claim 6
Dependent Claim
17 words
The invention as defined in claim 1 and including an abrasive resistant liner disposed within said housing.
Claim 7
Dependent Claim
213 words
In a system for controlling pressure in a well bore having a drill string through which a drilling fluid is directed, the combination comprising: means for directing drilling fluid through said drill string, a return line connected to said well bore for receiving the return drilling fluid from said bore, a choke means connected to said return line, said choke means including a housing having an inlet for said drilling fluid and an outlet for said drilling fluid, means defining an orifice adjacent said outlet, a valve means responsive to the rate of flow of said drilling fluid for valving said orifice means, said valve means including a valve head and connected valve stem, a cylinder adapted to contain a fluid pressure connected to the end of said choke housing, said valve stem extending into said cylinder, a piston connected to the extended end of said valve stem, an accumulator housing, a floating piston disposed in said accumulator housing dividing said housing into two expansible chambers, means for introducing a hydraulic fluid into one of said chambers, means for introducing a compressible gas into the other of said chambers, means connecting said one chamber in communication with said cylinder for maintaining a fluid pressure on said piston, and means for venting said cylinder.
Claim 8
Dependent Claim
213 words
In a system for controlling pressure in a well bore having a drill string through which a drilling fluid is directed, the combination comprising: means for directing drilling fluid through said drill string, a return line connected to said well bore for receiving the return drilling fluid from said bore, a choke means connected to said return line, said choke means including a housing having an inlet for said drilling fluid and an outlet for said drilling fluid, means defining an orifice adjacent said outlet, a valve means responsive to the rate of flow of said drilling fluid for valving said orifice means, said valve means including a valve head and connected valve stem, a cylinder adapted to contain a fluid pressure connected to the end of said choke housing, said valve stem extending into said cylinder, a piston connected to the extended end of said valve stem, an accumulator housing, a floating piston disposed in said accumulator housing dividing said housing into two expansible chambers, means for introducing a hydraulic fluid into one of said chambers, means for introducing a compressible gas into the other of said chambers, means connecting said one chamber in communication with said cylinder for maintaining a fluid pressure on said piston, and means for venting said cylinder.
Claim 9
Dependent Claim
116 words
A balanced piston well choke comprising: a choke housing having an inlet and outlet, a valve means disposed in alignment with said outlet responsive to varying rates of flow therethrough, means for imposing a back pressure on said valve means for maintaining said back pressure substantially constant for varying rates of flow therethrough, said latter means including a cylinder and associated piston, said piston being connected to said valve means to move therewith, means for imposing a fluid pressure on said piston to resist the movement thereof for imposing a predetermined back pressure thereon, said valve means including a valve head and connected valve stem, said valve stem being interconnected between said piston and valve head.
Claim 10
Dependent Claim
116 words
A balanced piston well choke comprising: a choke housing having an inlet and outlet, a valve means disposed in alignment with said outlet responsive to varying rates of flow therethrough, means for imposing a back pressure on said valve means for maintaining said back pressure substantially constant for varying rates of flow therethrough, said latter means including a cylinder and associated piston, said piston being connected to said valve means to move therewith, means for imposing a fluid pressure on said piston to resist the movement thereof for imposing a predetermined back pressure thereon, said valve means including a valve head and connected valve stem, said valve stem being interconnected between said piston and valve head.
Claim 11
Dependent Claim
80 words
The invention as defined in claim 7 wherein said means for imposing a fluid pressure on said piston includes: an accumulator housing, a floating piston disposed in said housing, means for introducing a hydraulic fluid on one side of said floating piston and a compressible gas on the other side of said floating piston, conduit means interconnected between said accumulator and said cylinder for conducting said hydraulic fluid therebetween, pump means for maintaining a predetermined pressure on said hydraulic fluid.
Claim 12
Dependent Claim
17 words
The invention as defined in claim 7 wherein said valve head and piston have substantially uniform diameters.
Claim 13
Dependent Claim
19 words
The invention as defined in claim 8 wherein the diameter of said floating piston is greater than said piston.
Claim 14
Dependent Claim
185 words
In a system for controlling pressure in a well bore having a drill string through which a drilling fluid is directed, the combination comprising: means for directing drilling fluid through said drill string, a return line connected to said well bore for receiving the return drilling fluid from said bore, a choke means connected to said return line, said choke means including a housing having an inlet and an outlet for said drilling fluid, means defining an orifice adjacent said outlet, a valve means responsive to the rate of flow of said drilling fluid for valving said orifice means, said valve means including a valve head and a connected valve stem, a cylinder adapted to contain a fluid pressure connected to said choke housing, said valve stem extending into said cylinder, a piston connected to the extended end of said valve stem, and a means connected to said cylinder for introducing a fluid pressure into said cylinder to maintain a substantially constant fluid back pressure on said piston as said connected valve means is rendered responsive to the rate of flow of said drilling fluid.
Claim 15
Dependent Claim
185 words
In a system for controlling pressure in a well bore having a drill string through which a drilling fluid is directed, the combination comprising: means for directing drilling fluid through said drill string, a return line connected to said well bore for receiving the return drilling fluid from said bore, a choke means connected to said return line, said choke means including a housing having an inlet and an outlet for said drilling fluid, means defining an orifice adjacent said outlet, a valve means responsive to the rate of flow of said drilling fluid for valving said orifice means, said valve means including a valve head and a connected valve stem, a cylinder adapted to contain a fluid pressure connected to said choke housing, said valve stem extending into said cylinder, a piston connected to the extended end of said valve stem, and a means connected to said cylinder for introducing a fluid pressure into said cylinder to maintain a substantially constant fluid back pressure on said piston as said connected valve means is rendered responsive to the rate of flow of said drilling fluid.
Claim 16
Dependent Claim
34 words
The invention as defined in claim 7 wherein said means for imposing a fluid pressure on said piston includes an accumulator operatively connected to said cylinder for exerting a predetermined pressure on said piston.
Claim 17
Dependent Claim
74 words
The invention as defined in claim 11 wherein said latter means includes an accumulator, a floating piston disposed in said accumulator for partitioning said accumulator into two expansible chambers, means for supplying a fluid in one chamber on one side of said floating piston to maintain a fluid pressure on said first mentioned piston, and means for introducing a compressible gas pressure into the other chamber on the other side of said floating piston.
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) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |