WO1997047852A1

WO1997047852A1 - Downhole lubricator valve

Info

Publication number: WO1997047852A1
Application number: PCT/US1997/010235
Authority: WO
Inventors: Brett Bouldin; Richard P. Rubbo
Original assignee: Pes, Inc.
Priority date: 1996-06-13
Filing date: 1997-06-13
Publication date: 1997-12-18
Also published as: AU3390397A

Abstract

A downhole well lubricator for engagement with a single hydraulic control line pressurized from the well surface. Hydraulic fluid pressure is provided to a hydraulic divertor or switch (30) which selectively distributes hydraulic pressure to an actuator (15) engaged with a valve (10). In a first position of the hydraulic switch (30), fluid pressure is provided against a first surface (18) of the actuator (15) to open valve (10). When the hydraulic switch (30) is moved to a second position, fluid pressure is provided against a second surface (20) of the actuator (15) to close the valve (10). The hydraulic switch (30) can be moved between the first and second position by controlling the differential hydraulic pressure between the control line and the well, by controlling fluctuations in the hydraulic fluid pressure, or by operating the hydraulic switch (30) with an electrical solenoid valve or other control system.

Description

DO HOLE LUBRICATOR VALVE

BACKGROUND OF THE INVENTION The present invention relates to the field of lubricator valves in wells. More particularly, the present invention relates to an improved downhole lubricator valve operable from a single hydraulic line pressurized from the well surface.

Lubricators incorporate tubular conduits for facilitating the entry of tools into a hydrocarbon producing well. Although wellheads prevent the release of pressurized well fluids from the well, wellheads impede the initial entry of well tools operable on wirelines, slicklines or coiled tubing. To move a well tool to the high pressure side of a wellhead, well tools are attached to a wireline or slickline and are placed in a lubricator. The lubricator is attached to the wellhead and a valve is opened to pressure equalize the well and the lubricator interior. A surface spooling unit can then lower the wireline or slickline through a stuffing box, injector head, or other entry mechanism at the lubricator upper end.

Surface located lubricators are impractical for long well tools. Alternatively, a valve can be positioned downhole in the wellbore, the downhole valve can be closed to isolate the wellhead from the well fluid pressure, and the tools can be run into the production tubing or riser. In this configuration, the production tubing or riser forms the lubricator housing, and the downhole valve is selectively opened and closed to control the pressure around the well tools. Conventional lubricators require at least two fluid control conduits to permit operation of the lubricator valve. One lubricator tool was shown in United States Patent No. 4,062,406 to Akkerman et al. (1977) , where a first fluid activatable means closed a lubricator valve and a second fluid activatable means opened the valve. In United States Patent No. 4,197,879 to Young (1980) and in 4,368,871 to Young (1983) , two hydraulic hoses controlled from a vessel were selectively pressurized to open and close a lubricator valve during well test operations. A separate control fluid was directed by each hydraulic hose so that one fluid pressure opened the valve and a different fluid pressure closed the valve. In United States Patent No. 4,476,933 to Brooks (1984) a piston shoulder functioned as a double acting piston in a lubricator valve. Two separate control lines were connected to conduits and conventional fittings to provide a high or low control fluid pressure to chambers on opposite sides of the piston shoulder. In United States Patent No. 4,522,370 to Noack et al. (1985), a combined lubricator and retainer valve was operable with first and second pressure fluids and pressure responsive members. As in other conventional designs, two control lines provided two hydraulic fluid pressures to the control valve.

When a lubricator valve is positioned downhole in a well, hydraulic control lines to the lubricator may extend for thousands of feet into the well. Each line significantly increases installation costs and the number of components potentially subject to failure. In addition, certain lubricator valve systems are in pressure communication with the tubing interior or exterior. When such valve systems are not isolated from such pressures, variations in pressure can inadvertantly open or close the lubricator valve. Accordingly, a need exists for an improved valve that reduces operating costs and increases the reliability of the valve system.

SUMMARY OF THE INVENTION

The present invention provides an improved downhole well valve for engagement with hydraulic fluid in a hydraulic line pressurized from the well surface. The apparatus comprises a housing having a bore for insertion downhole in the well, a valve operable to selectively open and close the housing bore, an actuator engaged with the valve wherein the actuator has a first surface for contacting hydraulic fluid pressure for movement in a first direction to open the valve and has a second surface for contacting hydraulic fluid for movement in a second direction to close the valve, and a hydraulic switch engaged with the hydraulic fluid for selectively diverting the hydraulic fluid pressure between the actuator first and second surfaces.

In other embodiments of the invention, the hydraulic switch can be responsive to the magnitude of the hydraulic fluid presure, to pressure pulses or other fluctuations in the hydraulic fluid pressure, or to other control signals. The actuator can comprise an annular piston and can reciprocate linearly within the housing.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates a schematic embodiment of the invention.

Figure 2 illustrates one embodiment of the invention when the hydraulic fluid is pressurized between zero and 3000 psi. Figure 3 illustrates one embodiment of the invention when the hydraulic fluid is pressurized over 3500 psi.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a lubricator valve that does not require multiple hydraulic fluid control lines and is not affected by pressure fluctuations within the tubing. The invention uses hydraulic fluid pressure to open and close the lubricator valve, and the fluid pressure is controlled from the well surface.

Referring to Figure 1, a schematic diagram of the invention is shown. Ball valve 10 is attached to housing 12 and is positioned downhole within well tubing 14. Housing 12 has an interior bore to permit the travel of fluids and well tools, and can be integrated into tubing 14 or can be separately set in sealing engagement with the interior wall of tubing 14. Valve 10 is rotatable to selectively open or close the bore through housing 12. Actuator 14 is engaged with valve 10 to selectively open and close valve 10 to seal the bore through housing 12.

As shown in Figure 1, actuator 15 can comprise a double acting actuator comprising cylinder or piston 16 having first surface 18 and second surface 20 in contact with hydraulic fluid 22. Piston 16 is linearly reciprocal within an interior volume or space collectively shown as first chamber 24 and second chamber 26. Seal 28 prevents migration of fluid 22 between first chamber 24 and second chamber 26. When the pressure of fluid 22 in first chamber 24 increases, piston 16 moves to increase the volume of first chamber 24 and to decrease the volume of second chamber 26. When the pressure of fluid 22 within second chamber 26 increases, piston 16 moves to increase the volume of second chamber 26 and to decrease the volume of first chamber 23. As defined herein, the phrase "pressure increase" means a relative pressure differential acting between first surface 18 and second surface 20 of piston 16, and can be accomplished by increasing or decreasing the pressure of fluid 22 in first chamber 24 or second chamber 26.

When there is a pressure increase in first chamber 24, actuator 15 opens valve 10 to open the bore through housing 12. When there is a pressure increase in second chamber 26, actuator 15 closes valve 10 to close the bore through housing 12. The invention preferably requires a controllable pressure increase to move valve 10 and does not require a power spring to return valve 10 to an open or closed position.

Hydraulic switch 30 selectively directs hydraulic fluid 22 pressure to first chamber 24 and second chamber 26. As shown in Figure 1, hydraulic switch 30 has four ports A - D, and is shown as a two-position pilot operated valve. Port A is connected to single control line 32 which provides hydraulic fluid 22 pressure from the well surface. Pressure relief valve 34 can retain the pressure of hydraulic fluid 22 acting against Port A. Port B is connected with hydraulic line 36 to first chamber 24. When the pressure of hydraulic fluid 22 at Port A is in a selected range such as between zero and 3000 psi, hydraulic switch 30 transfers the pressure of hydraulic fluid 22 pressure from Port A to Port B, and into communication with first chamber 24.

Port D is connected to line 38 which can be discharged into the bore of tubing 14 or can be returned to the well surface or another selected location. Check valve 40 prevents well fluids within the tubing 14 bore from entering line 38 and isolates line 38 from fluid pressures within tubing 14. Port C is connected to line 42 which is connected to second chamber 26. When there is a pressure increase of hydraulic fluid 22 within first chamber 24 and piston 16 moves to compress hydraulic fluid 22 within second chamber 26, hydraulic fluid 22 is moved through line 42 toward Port C, exits Port D to move through line 38, and is discharged through check valve 40. As piston 16 moves to reduce the volume of second chamber 26, valve 10 is opened.

To close valve 10, the pressure of hydraulic fluid 22 in control line 32 is increased at the well surface. Such pressure is diverted through pilot line 44 to chamber 46 of hydraulic switch 30. A pressure increase within chamber 46 moves piston 48 against return spring 50, thereby moving hydraulic switch 30 from a first position to a second position. In this second position, Port A communicates with Port C, and Port B communicates with Port D. Pressure increases of hydraulic fluid 22 in control line 32 are communicated from Port A to Port C and to second chamber 26 within actuator 15, thereby causing the volume of second chamber 26 to increase as piston 16 moves to close valve 10. The volume of first chamber 24 decreases, moving hydraulic fluid 22 through line 36 toward Port B, through hydraulic switch 30 to Port D, and through check valve 40.

As hydraulic fluid 22 is pressurized in the second position of hydraulic switch 30, hydraulic fluid 22 is moved from Port C toward second chamber 26. To selectively control the rate of such movement and the correcponding pressure increase of hydraulic fluid 22 within second chamber 26, check valve 52 causes hydraulic fluid 22 to move through fluid restrictor 54. Restrictor 54 controls the flow rate of hydraulic fluid 22, and can comprise a simple aperture within a housing. When the flow of hydraulic fluid 22 is reversed to move from second chamber 26 toward Port C, hydraulic fluid 22 moves freely through check valve 52 and is not impeded by restrictor 54.

To return hydraulic switch 30 to the first position, the pressure of hydraulic fluid 22 is decreased at the well surface, reducing the pressure of hydraulic fluid 22 within chamber 46. Spring 50 returns piston 48 to the first position so that Port A communicates with Port B, and Port C communicates with Port D. In this fashion, hydraulic switch 30 can be moved between the first and second position by increasing and decreasing the pressure of hydraulic fluid 22 within control line 32. As hydraulic switch 30 is moved between the first and second position, actuator 15 is similarly moved to open and close valve 10 independent of any other fluid pressures inside or outside of tubing 14, and independent of other control lines other than single control line 32.

Hydraulic switch 30 performs the function of alternating the hydraulic pressure from control line 32 to first chamber 24 or second chamber 26 of actuator 25, and can be configured to divert pressures to more than two chambers or tools. As shown in Figure 1, hydraulic switch 30 can comprise a pilot operated valve responsive to the differential pressure of hydraulic fluid 22 within control line 32 and the tubing interior. In other embodiments of the invention, hydraulic switch 30 can include an electrically operated switch such as a solenoid actuated switch which selectively permits direction of the pressure for hydraulic fluid 22. The electrically operated hydraulic switch could be operated through electrical signals or acoustic or pressure signals transmitted from the well surface.

In another embodiment of the invention, hydraulic switch 30 can be configured as a hydraulic fluid diverter which selectively directs all of the hydraulic fluid 22 pressure to either first chamber 24 or to second chamber 26. In such embodiment of the invention, a pressure increase in control line 32 is transmitted to first chamber 24, moving piston 16 to open valve 10. Releasing the pressure of hydraulic fluid 22 in control line 32 shifts hydraulic switch 30 to a neutral position. Another pressure increase in the pressure of hydraulic fluid 22 within control line 32 shifts hydraulic switch 30 to direct hydraulic fluid 22 pressure to second chamber 26, thereby moving piston 16 to close valve 10. When the pressure of hydraulic fluid 22 in control line 32 is relaxed, hydraulic switch 32 moves to the neutral position so that further increases and decreases in hydraulic fluid 22 pressure can be repeated. In this embodiment of the invention, hydraulic switch 30 can be configured so that pressure increases or decreases, or certain combinations or patterns of such fluctuations, operate hydraulic switch 22.

Figure 2 illustrates a representative embodiment of the invention wherein housing 56 is formed with first housing section 58 and second housing section 60. Hydraulic switch 62 is in a first position as shown in Figure 2. Control line 32 provides hydraulic fluid pressure through pressure relief valve 34 to Port A, and such fluid pressure is transmitted through hydraulic switch 62 to Port B and to first chamber 24. As the volume of second chamber 26 is reduced, hydraulic fluid 22 is moved through line 42 to Port C, travels through hydraulic switch 62, and exits Port D through check valve 40. Actuator 15 is operated to open valve 10.

Figure 3 illustrates the operation of hydraulic switch 62 to close valve 10. Hydraulic switch 62 is shown in a second position wherein the pressure of hydraulic fluid 22 in control line 32 is increased above a selected quantity. As shown in Figure 3, the fluid pressure within control line 32 exceeds 3500 psi, thereby operating hydraulic fluid 22 within pilot line 64 to enter aperture 66. As pressurized hydraulic fluid 22 enters aperture 66, such pressure acts against piston 68 and moves piston 68 to compress spring 70. As spring 70 compresses to permit the movement of piston 68, hydraulic switch 62 is converted from the initial first position to a second position wherein Port A communicates with Port C, and Port B communicates with Port D. The operation and function between Ports A - D is similar to that described for Figure 1.

The invention provides a unique lubricator valve that is operable from the well surface with a single control line. Unintentional movement of the valve due to pressure fluctuations within the tubing bore is eliminated, and the full power provided through the hydraulic control line can be diverted in either direction to open and close the lubricator valve.

Although the invention has been described in terms of certain preferred embodiments, it will be apparent to those of ordinary skill in the art that modifications and improvements can be made to the inventive concepts herein without departing from the scope of the invention. The embodiments shown herein are merely illustrative of the inventive concepts and should not be interpreted as limiting the scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. A downhole well lubricator valve for engagement with hydraulic fluid in a hydraulic line pressurized from the well surface, comprising: a housing for insertion downhole in the well, wherein said housing has a bore therethrough; a valve operable to selectively open and close said housing bore; an actuator engaged with said valve, wherein said actuator has a first surface for contacting hydraulic fluid pressure and for moving in a first direction to open said valve, and has a second surface for contacting hydraulic fluid and for moving in a second direction to close said valve; and a hydraulic switch engaged with the hydraulic fluid for selectively diverting the hydraulic fluid pressure to said actuator first surface and to said actuator second surface.

2. A lubricator valve as recited in Claim 1, wherein said hydraulic switch is responsive to the magnitude of the hydraulic fluid pressure to selectively divert the hydraulic fluid pressure into contact with said actuator first surface or said actuator second surface.

3. A lubricator valve as recited in Claim 1, wherein said hydraulic switch is responsive to pressure pulses in the hydraulic fluid pressure to selectively divert the hydraulic fluid pressure into contact with said actuator first surface or said actuator second surface.

4. A lubricator valve as recited in Claim 1, wherein said valve comprises a ball valve.

5. A lubricator valve as recited in Claim 1, wherein said actuator comprises an annular piston located within an annular cavity within said housing.

6. A lubricator valve as recited in Claim 1, further comprising an exit port communicating with said actuator first surface and with said actuator second surface for selectively releasing hydraulic fluid into the well.

7. A lubricator valve as recited in Claim 1, wherein said hydraulic switch comprises a four-way two-position pilot operated valve.

8. A lubricator valve as recited in Claim l, wherein said hydraulic switch is electrically activated to selectively divert the hydraulic fluid pressure into contact with said actuator first surface or said actuator second surface.

9. A lubricator valve as recited in Claim 1, wherein said hydraulic switch is capable of selectively releasing hydraulic fluid pressure from said actuator first surface or from said actuator second surface for moving said actuator to operate said valve.

10. A lubricator valve as recited in Claim 1, wherein said hydraulic switch is capable of diverting the entire pressure of hydraulic fluid within the control line to said actuator first surface or to said actuator second surface.

11. A downhole well lubricator valve for engagement with hydraulic fluid in a hydraulic control line pressurized from the well surface, comprising: a housing for insertion downhole in the well, wherein said housing has a bore therethrough; a valve operable to selectively open and close said housing bore; a double acting actuator within said housing and engaged with said valve, wherein said said actuator has a first surface for contacting hydraulic fluid pressure and for linear movement in a first direction to open said valve, and has a second surface for contacting hydraulic fluid and for linear movement in a second direction opposite to said first direction to close said valve; and a hydraulic switch engaged with the hydraulic fluid in the hydraulic line for selectively diverting the hydraulic fluid pressure to said actuator, wherein said hydraulic switch diverts hydraulic fluid pressure to said actuator first surface when the hydraulic fluid pressure in the hydraulic control line is less than a selected quantity, and wherein said hydraulic switch diverts hydraulic fluid pressure to said actuator second surface when the hydraulic fluid pressure in the hydraulic control line is greater than a selected quantity.

12. A lubricator valve as recited in Claim 11, wherein said actuator comprises an annular piston located within an annular cavity within said housing.

13. A lubricator valve as recited in Claim 11, wherein said hydraulic switch is capable of diverting the entire pressure of hydraulic fluid within the control line to said actuator first surface or to said actuator second surface.

14. A lubricator valve as recited in Claim 11, wherein said actuator comprises a floating piston within a cavity in said housing which defines a first chamber in contact with said actuator first surface, and defines a second chamber in contact with said actuator second surface.

15. A lubricator valve as recited in Claim 11, further comprising a pressure relief valve between the hydraulic control line and said hydraulic switch.

16. A lubricator valve as recited in Claim 11, further comprising a check valve between said actuator and the exterior of said housing.

17. A lubricator valve as recited in Claim 11, further comprising a check valve between said hydraulic switch and the exterior of said housing.