Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3786865 A
Publication typeGrant
Publication dateJan 22, 1974
Filing dateMar 6, 1973
Priority dateMar 6, 1973
Publication numberUS 3786865 A, US 3786865A, US-A-3786865, US3786865 A, US3786865A
InventorsTausch G, Watkins F
Original AssigneeCamco Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Lockout for well safety valve
US 3786865 A
Abstract
In a well safety valve for controlling the fluid flow through a well tubing in which the valve closure means is controlled by longitudinal movable tubular member, the improvement of lockout means for locking the valve closure member in the open position by providing a second tubular member axially aligned with the first tubular member and normally positioned below the valve closure member. Means on the second member for moving the second member upwardly for holding the valve closure member open. Holding means for holding the second member in the upward position for locking the valve open. The holding means being releasable for resetting and closing the valve if desired.
Images(2)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Unite States Patent [19 Tausch et a1.

[451 Jan. 22, 1974 LOCKOUT FOR WELL SAFETY VALVE [75] Inventors: Gilbert H. Tausch; Fred E. Watkins,

both of Houston, Tex.

[52] U.S. Cl. 166/224 S, 137/460, 137/495,

251/58 [51] Int. Cl ..E21b 43/12 {58] Field of Search 166/72, 224, 226; 137/315, 137/461, 460, 495, 494, 498, 510, 614.11, 614.2; 251/31, 58, 62, 63, 77

[56] References Cited UNITED STATES PATENTS 3,696,868 10/1972 Taylor, Jr. 166/224 S 3,078,923 2/1963 Tausch 166/2248 R25,47l 11/1963 Fredd 166/224 S 3,126,908 3/1964 Dickens 137/460 3,470,903 10/1969 Scott 1'37/495 i m a 3,398,762 8/1968 Fredd 137/498 Primary Examiner-James A. Leppink Attorney, Agent, or FirmJefferson D. Giller; James F. Weiler; William A. Stout 5 7 ABSTRACT In a well safety valve for controlling the fluid flow through a well tubing in which the valve-closure means is controlled by longitudinal movable tubular member, the improvement of lockout means for locking the valve closure member in the open position by providing asecond tubular member axially aligned with the first tubular member and normally positioned below the valve closure member, Means on the second member for moving the second member upwardly for holding the valve closure member open. Holding means for holding the second member in the upward position for locking the valve open. The holding means being releasable for resetting and closing the valve if desired.

10 Claims, 4 Drawing Figures PATENTEI] JAN 2 21974 saw 2 [1F 2 LOCKOUT FoR WELL SAFETY VALVE BACKGROUND OF THE INVENTION Various safety valves have been used in the past in a well tubing to shut off the production of well fluids from oil or gas wells such as shown in U.S. Pat. Nos. 3,078,923 adn 3,627,042 in which the opening and closing of the valve is controlled by movement of a longitudinal movable tubular member. Generally, the tubular member is generally pressure actuated and requires close tolerances which are subject to binding by deposits such as sand. One cause of safety valve problems is the inability to operate the safety valve due to the binding of the movable tubular member as a result of deposits or interference from accumulated sand that is often found in produced well fluids. Of course, if the movable tubular member becomes stuck, the valve cannot be actuated. If the safety valve is retrievable, it can be removedand repaired, but if it forms a portion of the well tubing, thetubing string must be pulled to perform any safetyvalve repairs.

Such operations are costly and time consuming. It is sometimes desirable to delay the repair of the safety valve but still work on or produce from the well. To do this the safety valve is locked out, which means it is mechanically moved to the fully opened position, such as for the purpose of producing from the well or performing other work in the tubing below the safety valve. While a lockout of the safety valve will not eliminate the need for pulling the safety valve or tubing for safety valve repair, the lockout will allow the well to stay on production or perform other work functions in the tubing until the safety valve work can be conveniently scheduled. One type of safety valve lockout is shown in U.S. Pat. No. 3,696,868 in which a lockout sleeve is moved downwardly against the top of the longitudinal tubular member for moving the tubular member in a direction to open the valve and lock the valve opened. However, if the cause of the failure is due to the sticking or binding of the tubular member, it may be difficult to obtain a sufficient movement of the tubular member to provide the desired lockout.

The present invention is directed to a lockout for a well safety valve which cannot inadvertently be locked out while the valve is in the open position and which does not require actuation of the actuating longitudinal movable tubular member so that sticking of the tubular member will not prevent operation of the lockout.

SUMMARY The present invention is generally directed to providing a lockout of a well safety valve that does not require moving the longitudinal movable actuating member of the safety valve.

The present invention is further directed to the improvement in a well safety valve which controls the fluid flow through a well tubing and includes a longitudinal movable tubular member controlling the movement of the valve closure means of a lookout means for locking the valve closure member in the open position by providing a second tubular member axially aligned with the first tubular member and normally positioned below the valve closure member for movement upwardly for holding the valve closure member open.

Yet a further object of the present invention is the provision of a lockout which cannot inadvertently lock out the valve while the valve is in the open position.

The present invention further includes releasable holding means for engaging and holding the second member in an upward position for locking the valve open, but allowing the lockout tubular member to be moved out of the valve holding position for allowing the valve to be reset and closed.

Still a further object of the present invention is the provision of a lockout means that includes a recess having beveled edges at both ends and designed so that accidental operation may not occur when wireline or pump-in operations are being performed.

In addition, a lockout mechanism is provided that has a straight through streamline flow configuration.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is an elevational view, partly in cross section, of the top portion of a tubing retrievable safety valve,

FIG. 1B is a continuation of FIG. 1A showing the bottom portion of the safety valve and the lockout mechanism of the present invention shown in the inactive position,

FIG. 2 is a fragmentary elevational view, partly in cross section, illustrating the actuation of the lockout mechanism for holding the valve closure member in the open position, and

FIG. 3 is a fragmentary elevational view, in cross section, of a modified lockout mechanism of a permanent type as compared to the resetting type of FIGS. 1 and DESCRlPTlON OF THE PREFERRED I EMBODIMENT For purposes of illustration only, the present invention will be described in connection with a tubing retrievable flapper type safety valve. However, it is to be recognized that the present lockout mechanism may be used with other types of safety valves including those having different valve closure means.

Referring now to the drawings, in particular to FIGS. 1A and 1B, the reference numeral 10 generally indicates a well safety valve of the tubing retrievable type adapted to form a portion of the well tubing 12 by being connected therein by a suitable threaded connections 14 and 16. The safety valve 10 is provided to control the fluid flow thorugh the bore 30 of the well tubing 12 and valve 10. Under normal flow conditions the safety valve 10 is in the open position. The safety valve 10 is closed in the event of equipment failure or other undesirable conditions to shut off well production.

The safety valve 10 generally includes a valve body 18, a valve closure member such as a flapper valve 20, and a longitudinal movable tubular member 22 for controlling the movement of the flapper valve 20. The flapper valve 20 is carried about a pivot 24 and may include a spring 26 for yieldably urging the flapper valve 20 about the pivot 24 and on to an annular valve seat 28 for closing the valve and blocking upward flow of fluid through the bore-3t) of the valve 10 and tubing 12.

The tubular member 22 is longitudinally movable in the valve body 18 and when the lower end 32 of the member 22 is moved downwardly, the end 32 contacts the flapper 20 moving flapper 20 off of the valve seat 28 and into a downward and open position, as shown in FIG. 18, thereby permitting fluid flow through the bore 30. However, when the tubular member 22 is moved upwardly and its lower end 32 is moved above the valve seat 28, the spring 26 and/or fluid flow upwardly through the valve closes the flapper 20.

Any suitable control means for controlling movement of the tubular member 22 may be used. For example, a biasing spring 34 may be provided positioned between a shoulder 36 on the valve body 18 and a shoulder 38 on the tubular member 22 for biasing the tubular member 22 upwardly and in a direction allowing the flapper to close. In order to provide means for moving the tubular member 22 in a downward direction, a piston 40 may be provided on the tubular member 22 for movement in a cylinder 42 formed by seals 44 and 46 between the member 22 and the valve body 18. A control line 50 may be provided leading to the well surface for'supplying a fluid therein which communicates with the cylinder 42 for controlling the movement of the piston 40 and thus of the tubular member 22. If fluid pressure is applied through the line 50 and into the cylinder 42, the piston 40 and the tubular member 22 is moved downwardly overcoming the spring 34 and opens the flapper 20. The flapper 20 is closed by reducing the fluid pressure in the control line 50 and thus in the chamber 42 allowing the spring 34 to move the tubular member 22 upwardly releasing the flapper valve 20. The above described safety valve is generally conventional.

The safety valve 10 may fail for some reason. Of course, if it fails with the tubular member 22 held in the downwardly extended position then there is no need for a lockout.

However, in the event the safety valve becomes inoperative when the tubular member 22 is in the upward or partially upward position, it may be desirable to lock out the safety valve. That is, the safety valve 10 is locked out by holding valve closure 20 in the fully opened position for purposes of allowing well production or performing various types through tubing work until the safety valve may be conveniently retrieved and repaired. One cause of safety valve problems is the inability to operate the safety valve due to the binding of the tube 22 against the valve body 18 and seals 44 and 46 as a result of deposits such as accumulated sand that is often found in producing well fluids. If the failure is due to the binding or sticking of the tubing 22, then it is difficult to utilize lockout mechanisms that require movement of the tubular member 22 for opening and locking out the valve 20.

As best seen in FIG. 1B, the present invention utilizes a lockout means for locking the valve closure member 20 in the open position by providing a second tubular lockout member 60 telescopically positioned in the valve 10 below the valve 20. Normally, the lockout member 60 is held in a downward position by a suitable means such as a detent 62 engaging a notch 64 on the lockout member 60. Suitable means are provided on the lockout member 60 for moving the lockout member 60 upwardly or downwardly, if desired, such as a recess 66 having upper and lower beveled edges 68 and 70.

As best seen in FIG. 2, any suitable type of tool such as shown in dotted outline 72, such as a Z-lock of Camco, Incorporated, may be utilized to be moved down the well bore 30 by either conventionally wireline or pump-down operations, open the valve 20 and engage the recess 66. Upward movement of the tool 72 will move the lockout member 60 upwardly whereby the upper end 61 of the member 60 will engage and hold the flapper valve 20 in the upper postion. The detent 62 will engage a lower notch 74 on the lockout member 60 holding the lockout member 60 in the upper position for holding the valve 20 open. The beveled edges 68 and on the recess 66 are designed to avoid catching on shoulders of well tools passing down the bore 30 and through the safety valve 10 so that accidental operation of the lockout member 60 will not occur when normal wireline or pump-in operations are being performed through the safety valve 10.

Furthermore, it is to be noted that lockout member 60 is normally positioned with the upper end 61 of the member 60 adjacent the lower end 62 of the operating tubular member 22 when the tubular member 22 is in the downward position holding the valve 20 open. This prevents inadvertent actuation of the lockout member 60 while the valve is held in the open position. That is, even if a well tool accidentally engages member 60, the member 60 could not be moved upwardly against the hydraulic force holding the member 22 downwardly or if member 60 were moved upwardly, the pressure in the control line 50 would increase indicating such movement. It is undesirable to allow the lockout member to be inadvertently actuated while the valve 20 is held in the open position since this would thereafter prevent the valve 10 from preforming its normal safety function.

Normally, the lockout member 60 need not be resettable to a downward position so that the valve 20 can close since the safety valve 10 would normally be retrieved and repaired as soon as possible. However, the detent 62 and notches 64 and 74 allow the lockout member 60 to be re-engaged by the tool 72 and moved to the downward position for resetting and allowing closure of the valve 20 if desired.

Of course, other and further modifications of the present invention may be utilized. Referring now to FIG. 3, a further embodiment of the present invention is shown wherein like parts to those of FIGS. 1A, 1B and 2 are shown with like numbers and the addition of the suffix a. In the embodiment of FIG. 3, the lockout member 60a includes a plurality of downwardly directed ratchet teeth on the exterior of member 60a for coacting with a ratchet clutch 82 having a plurality of upwardly directed teeth 83. The ratchet member 82 is urged inwardly by one or more garter springs 84. Thus, as the lockout member 60a is moved upwardly by a suitable tool, the ratchet teeth 80 on the lockout member 60a will ratchet past the teeth 83 on the clutch 82 for holding the lockout member 60a in the upward position for locking the valve 20a in the open position. The coacting teeth 80 and 83 will allow the lockout member 600 to be held in whatever upward position it is carried by the tool 72. In addition, the coacting teeth 80 and 83 will to some extent hold the member 60a initially in the downward position. The ratchet type teeth 80 and 83 normally provide a permanent lockout although, of course, the teeth 80 and 83 may be made shearable if desired for resetting the lockout member 60a.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein. While presently preferred embodiments of the invention have been given for the purpose of disclosure, numerous changes in the detail of construction and arrangement of parts may be provided, without departing from the spirit of the invention and the scope of the appended claims.

What is claimed is:

1. In a well safety valve for controlling the fluid flow through a well tubing, the valve adapted to be positioned in the well tubing and having a housing and having a valve closure member moving between open and closed positions, a first longitudinally movable tubular member for controlling the movement of the valve closure member, first means for moving the tubular member in a first direction, second means for moving the tubular member in a second direction, the improvement of lockout means for locking the valve closure member in the open position comprising,

a second tubular member axially aligned with the first tubular member and normally positioned below the valve closure member,

means on the second member for moving the second member upwardly for holding the valve closure member open, and

. holding means for engaging and holding the second member in the upward position for locking the valve open.

2. The apparatus of claim 1 wherein the upper end of the second tubular member is normally positioned to be adjacent the lower end of the first tubular member when the first tubular member is in its fully extended downward position thereby preventing inadvertent locking out of the valve closure member when the valve is in the open position.

3. The apparatus of claim 1 including releasable holding means for initially holding the second member in the downward position.

4. The apparatus of claim 1 wherein the means for moving the second member upwardly includes,

a tool engaging recess on the interior of the second member.

5. The apparatus of claim 4 wherein the recess includes beveled edges on the both ends of the recess for preventing accidental acutation of the second member.

6. The apparatus of claim 1 wherein the holding means is releasable.

7. In a well safety valve for controlling the fluid flow through a well tubing, the valve adapted to be positioned in the well tubing and including a housing and a valve closure member moving between open and closed positions, a first longitudinally movable tubular member for controlling the movement of the valve closure member, spring means for biasing the tubular member in a first direction for closing the valve closure member, a piston and cylinder assembly for moving the first tubular member in a direction for opening the valve closure member, the improvement in lockout means for locking the valve closure member in the open position comprising,

a second tubular member axially aligned with the first tubular member and normally positioned below the valve closure member,

releasable holding means for initially holding the second member in the downward position,

a tool engaging recess on the interior of the second member for moving the second member upwardly for holding the valve closure member open, and

locking means between the second member and the housing for lockingthe second member in the upward position for locking the valve open.

8. The apparatus of claim 7 wherein the upper end of the second tubular member is normally postioned to be adjacent the lower end of the first tubular member when the first tubular member is in its fully extended downward position thereby preventing inadvertent locking out of the valve closure member when the valve is in the open position.

9. In a well safety valve for controlling the fluid flow through a well tubing, the valve adapted to be positioned in the well tubing and including a housing and a flapper valve closure member moving between open and closed positions, a first longitudinally movable tubular member for controlling the movement of the flapper valve member, spring means for biasing the tubular member in a direction for closing the flapper closure member, a piston and cylinder assembly for moving the first tubular member in a direction for opening the flapper closure member, the improvement in lockout means for locking the flapper closure member in the open position comprising,

a second tubular member axially aligned with the first tubular member and normally positioned below and out of engagement with the flapper closure member,

engaging means on the second member for allowing movement of the second member upwardly for engaging and holding the flapper member open, and

holding means for engaging and holding the second member in the upward position for holding the valve open. I 10. The apparatus of claim 9 wherein the upper end of the second tubular member is normally positioned to be adjacent the lower end of the first tubular member when the first tubular member is in its fully extended downward position thereby preventing inadvertent locking out of the valve closure member when the valve is in the open position.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US25471 *Sep 13, 1859ThosImprovement in sewing-machines
US3078923 *Apr 15, 1960Feb 26, 1963Camco IncSafety valve for wells
US3126908 *Oct 3, 1960Mar 31, 1964 figure
US3398762 *Oct 21, 1965Aug 27, 1968Otis Eng CoValves
US3470903 *Jan 25, 1967Oct 7, 1969Byron Jackson IncPressure openable tubing tester
US3696868 *Dec 18, 1970Oct 10, 1972Otis Eng CorpWell flow control valves and well systems utilizing the same
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3882935 *Dec 26, 1973May 13, 1975Otis Eng CoSubsurface safety valve with auxiliary control fluid passage openable in response to an increase in control fluid pressure
US3955623 *Apr 22, 1974May 11, 1976Schlumberger Technology CorporationSubsea control valve apparatus
US3955624 *Oct 21, 1974May 11, 1976Continental Oil CompanySafety valve for controlling flow in a flow conductor
US3967647 *Apr 22, 1974Jul 6, 1976Schlumberger Technology CorporationSubsea control valve apparatus
US4009753 *Mar 22, 1976Mar 1, 1977Schlumberger Technology CorporationSubsea master valve apparatus
US4071088 *Sep 19, 1975Jan 31, 1978Hydril CompanyRetrievable safety valve
US4077473 *Apr 18, 1977Mar 7, 1978Camco, IncorporatedWell safety valve
US4109724 *Oct 27, 1977Aug 29, 1978Halliburton CompanyOil well testing valve with liquid spring
US4109725 *Oct 27, 1977Aug 29, 1978Halliburton CompanySelf adjusting liquid spring operating apparatus and method for use in an oil well valve
US4356867 *Sep 28, 1981Nov 2, 1982Baker International CorporationTemporary lock-open tool for subterranean well valve
US4411316 *Feb 9, 1981Oct 25, 1983Baker International CorporationSubterranean well valve with lock open mechanism
US4449587 *Jan 6, 1983May 22, 1984Otis Engineering CorporationSurface controlled subsurface safety valves
US4552219 *Oct 5, 1983Nov 12, 1985Hydril CompanySubsurface safety valve
US4574889 *Mar 11, 1985Mar 11, 1986Camco, IncorporatedMethod and apparatus for locking a subsurface safety valve in the open position
US4624315 *Oct 5, 1984Nov 25, 1986Otis Engineering CorporationSubsurface safety valve with lock-open system
US4651827 *May 14, 1986Mar 24, 1987Total Compagnie Francaise Des PetrolesHydraulically controlled safety valves for incorporation in production tubes of hydrocarbon production wells
US4723606 *Jan 13, 1987Feb 9, 1988Otis Engineering CorporationSurface controlled subsurface safety valve
US5167284 *Jul 18, 1991Dec 1, 1992Camco International Inc.Selective hydraulic lock-out well safety valve and method
US5249630 *Jan 21, 1992Oct 5, 1993Otis Engineering CorporationPerforating type lockout tool
US5598864 *Oct 19, 1994Feb 4, 1997Camco International Inc.Subsurface safety valve
US6059041 *Jul 17, 1997May 9, 2000Halliburton Energy Services, Inc.Apparatus and methods for achieving lock-out of a downhole tool
US6523614Apr 19, 2001Feb 25, 2003Halliburton Energy Services, Inc.Subsurface safety valve lock out and communication tool and method for use of the same
US6575249May 17, 2001Jun 10, 2003Thomas Michael DeatonApparatus and method for locking open a flow control device
US6659185Nov 12, 2002Dec 9, 2003Halliburton Energy Services, Inc.Subsurface safety valve lock out and communication tool and method for use of the same
US6705593Mar 25, 2002Mar 16, 2004Schlumberger Technology CorporationValve closing device
US6742595Nov 12, 2002Jun 1, 2004Halliburton Energy Services, Inc.Subsurface safety valve lock out and communication tool and method for use of the same
US6880641Aug 6, 2003Apr 19, 2005Halliburton Energy Services, Inc.Subsurface safety valve and method for communicating hydraulic fluid therethrough
US6953093Oct 26, 2004Oct 11, 2005Halliburton Energy Services, Inc.Communication tool for accessing a non annular hydraulic chamber of a subsurface safety valve
US6991040Jun 20, 2003Jan 31, 2006Weatherford/Lamb, Inc.Method and apparatus for locking out a subsurface safety valve
US7032672Oct 26, 2004Apr 25, 2006Halliburton Energy Services, Inc.Subsurface safety valve having a communication tool accessible non annular hydraulic chamber
US7188674Apr 4, 2003Mar 13, 2007Weatherford/Lamb, Inc.Downhole milling machine and method of use
US7249635Jan 4, 2006Jul 31, 2007Halliburton Energy Services, Inc.Communication tool for accessing a non annular hydraulic chamber of a subsurface safety valve
US7347270Oct 19, 2005Mar 25, 2008Schlumberger Technology CorporationRedundant hydraulic system for safety valve
US7373983Mar 13, 2007May 20, 2008Weatherford/Lamb, Inc.Downhole milling machine and method of use
US7409996Oct 25, 2004Aug 12, 2008Baker Hughes IncorporatedControl system communication and lock open tool and method for locking open a safety valve and communicating with surface
US7475733May 31, 2007Jan 13, 2009Halliburton Energy Services, Inc.Communication tool for accessing a non annular hydraulic chamber of a subsurface safety valve
US7510010Jan 10, 2006Mar 31, 2009Halliburton Energy Services, Inc.System and method for cementing through a safety valve
US7717185 *Jul 14, 2008May 18, 2010Baker Hughes IncorporatdLock open and control system access apparatus for a downhole safety valve
US7775269Aug 17, 2010Halliburton Energy Services, Inc.Communication tool for accessing a non annular hydraulic chamber of a subsurface safety valve
US7866401Jan 24, 2005Jan 11, 2011Schlumberger Technology CorporationSafety valve for use in an injection well
US7954552May 14, 2008Jun 7, 2011Schlumberger Technology CorporationOverriding a primary control subsystem of a downhole tool
US20040007365 *Jun 20, 2003Jan 15, 2004Weatherford/Lamb, Inc.Method and apparatus for locking out a subsurface safety valve
US20040026087 *Aug 6, 2003Feb 12, 2004Dennistoun Stuart M.Subsurface safety valve and method for communicating hydraulic fluid therethrough
US20040045714 *Apr 4, 2003Mar 11, 2004Weatherford/Lamb Inc.Downhole milling machine and method of use
US20050056414 *Oct 26, 2004Mar 17, 2005Dennistoun Stuart M.Communication tool for accessing a non annular hydraulic chamber of a subsurface safety valve
US20050056430 *Oct 26, 2004Mar 17, 2005Dennistoun Stuart M.Subsurface safety valve having a communication tool accessible non annular hydraulic chamber
US20050098325 *Oct 25, 2004May 12, 2005Myerley Thomas S.Control system communication and lock open tool and method for locking open a safety valve and communicating with surface
US20060086509 *Oct 19, 2005Apr 27, 2006Schlumberger Technology CorporationRedundant Hydraulic System for Safety Valve
US20060113081 *Jan 4, 2006Jun 1, 2006Halliburton Energy ServicesCommunication tool for accessing a non annular hydraulic chamber of a subsurface safety valve
US20060162932 *Jan 24, 2005Jul 27, 2006Schlumberger Technology CorporationSafety Valve for Use in an Injection Well
US20070158082 *Jan 10, 2006Jul 12, 2007Williamson Jimmie RSystem and method for cementing through a safety valve
US20070181305 *Mar 13, 2007Aug 9, 2007Mcgavern Cecil G IiiDownhole milling machine and method of use
US20070227738 *May 31, 2007Oct 4, 2007Halliburton Energy Services, Inc.Communication tool for accessing a non annular hydraulic chamber of a subsurface safety valve
US20090114389 *Jan 13, 2009May 7, 2009Dennistoun Stuart MCommunication Tool for Accessing a Non Annular Hydraulic Chamber of a Subsurface Safety Valve
US20090283276 *Nov 19, 2009Schlumberger Technology CorporationOverriding a primary control subsystem of a downhole tool
US20100006296 *Jan 14, 2010Anderson David ZLock Open and Control System Access Apparatus for a Downhole Safety Valve
EP0892148A2 *Jul 17, 1998Jan 20, 1999Halliburton Energy Services, Inc.Apparatus and method for achieving lock-out of a downhole tool
WO2004007903A1Jul 9, 2003Jan 22, 2004Weatherford/Lamb, Inc.Method and apparatus for locking out a subsurface safety valve
Classifications
U.S. Classification166/323, 137/460, 137/495, 251/58
International ClassificationE21B34/00, E21B34/10
Cooperative ClassificationE21B34/102, E21B2034/005
European ClassificationE21B34/10L
Legal Events
DateCodeEventDescription
Jul 9, 1990ASAssignment
Owner name: CAMCO INTERNATIONAL INC., A CORP. OF DE, DELAWARE
Free format text: MERGER;ASSIGNOR:CAMCO, INCORPORATED, A CORP. OF TX.;REEL/FRAME:005366/0664
Effective date: 19891220