GB2242215A

GB2242215A - Head assembly for pump down equipment

Info

Publication number: GB2242215A
Application number: GB9106038A
Authority: GB
Inventors: J Lindley Baugh
Original assignee: Baker Hughes Inc
Current assignee: Baker Hughes Holdings LLC
Priority date: 1990-03-22
Filing date: 1991-03-21
Publication date: 1991-09-25
Also published as: CA2038798A1; GB9106038D0; NO911148L; NO911148D0

Abstract

Apparatus is provided for holding and mechanically releasing a cementing plug P or the like in a subterranean well. A cylindrical housing 101a, 101b concentrically carries a sleeve 106 for receipt of the plug P. A lock pin 115 holds the sleeve in position and is rotated to permit the sleeve to shift for release of an extension bridge 112 provided within the sleeve 106 and holding the plug in position. The plug then is pumped out of the apparatus and into the well with the cementitious fluid. Rotation and longitudinal movement of the apparatus can be effected at all times and cementitious fluid can be pumped completely through the apparatus before, during and after the release of the plug. <IMAGE>

Description

HEAD ASSEMBLY FOR PUMP DOWN EQUIPMENT BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION: The invention relates to an apparatus and method for holding and mechanically releasing a pump down means, such as a ball or wiper plug element used during the cementing operation of a subterranean oil or gas well.

2. DESCRIPTION OF THE PRIOR ART: As a step in the completion operation of a subterranean well, a casing is run into the well and the annular area exterior of the casing and within the open bore thereafter is cemented to secure the casing within the well. Cementing plugs, ball elements, and other pump down means are utilized in the cementir.g operation and are run ahead and behind the cement slurry in order to wipe mud off the walls of the casing or drill pipe and to prevent cement from being contaminated with the drilling fluid previously circulated within the casing and the well. Such plugs are often run into the well within the casing and behind a cement slurry in order to wipe the casing i.d. and close off check valves, open stage collars, and reclose stage collars during multi-stage cementing operations, and the like.

In the past, bead assemblies for holding and dropping cementing plugs and the like have been affixed below a kelly joint and above the upper most section of the casing conduit, and will release the plug by application of hydraulic pressure by use of piston elements in the plug dropping head assemblies to which are connected hydraulic hoses extending to a remote control panel. Obviously, in such a configuration, it is difficult, if not impossible, to rotate the kelly joint and/or casing conduit with the plug dropping head affixed thereon. At the very least, such operation tends to be extremely cumbersome.

Additionally, prior art plug dropping heads have not been able to be utilized in conjunction with the pumping of fluids which are utilized in one or more portions of the cementing or other remedial well operation, since the plug has elastomeric wiper fins extending along and contacting the inner wall of the plug dropping head and casing conduit. This problem has resulted in the temporary termination of a pumping operation while a plug dropping head is affixed to the casing conduit at the top of the well. Thereafter, the cementing operation is reactivated after dropping one or more plug assemblies. Even the temporary termination of the pumping operation can adversely affect the rheological properties of the cementitious or other remedial fluid within the well resulting in a loss of solids therein and viscosity.

The present invention addresses the problems set forth above and provides a plug dropping head which permits the casing and/or kelly joint to be continuously rotated or longitudinally manipulated at any time with the pump down means, or plug, carried therein and available for discharge therethrough at any time.

Additionally, the present invention also provides a plug dropping head assembly in which the cementitious fluid may be continuously pumped through the apparatus, from one end to the other, and down the casing string, both before, during and after the dropping of the plug, ball or other pump down means.

SUMMARY OF THE INVENTION The present invention provides an apparatus for holding and mechanically releasing a pump down means, such as a wiper plug, valve activating ball element, dart, or the like used during the cementing or other remedial operation of or within a conduit within a subterranean well. The apparatus is securable on a longitudinally and rotationally manipulatable conduit member communicating with the well such that no hydraulic auxiliary control lines extend from the apparatus. Accordingly, the apparatus may be freely rotated with the casing or other conduit string at all times.Additionally, the apparatus permits cementitious or other fluid to be transmitted completely through the apparatus at all times such that the apparatus may be positioned on the conduit without interference with the pumping of the cementitious or other remedial fluid, before, during and after the dropping of the plug or other pump down means.

The apparatus comprises an elongate cylindrical housing with a cylindrical sleeve which is concentrically disposed within the housing for receipt of the pump down means. Means for holding the sleeve are provided in a first position to prevent movement of the sleeve relative to the housing in a first direction.

Means are also provided for selectively releasing the sleeve from the first position to permit movement of the sleeve relative to the housing and extension means are provided within the sleeve and are movable between first and second extension positions, such that when the extension means is in one of the extension positions movement of the pump down means is prevented in one direction, and when the extension means is in the other of said positions movement of the pump down means is permitted through the apparatus. An annular cementing fluid transmission passageway is defined between the housing and the sleeve to permit continuous pumping of cementitious fluid through the apparatus and into the casing at all times while the apparatus is positioned on the casing for selective dropping of the plug, ball or other pump down means.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 constitutes a longitudinally extending half sectional view of the apparatus of the present invention with a casing conduit section extending to the well at the lowermost end thereof, the apparatus being illustrated in position for holding a cementing plug.

Fig. 2 is a view similar to that of Fig. 1, illustrating the apparatus subsequent to dropping the cementing plug.

Fig. 3 is a cross-sectional view taken along lines 3-3 of Fig. 1.

Fig. 4 is a view taken along lines 4-4 of Fig. 1.

Fig. 5 is a cross-sectional view taken along lines 5-5 of Fig. 1.

Fig. 6 is a view similar to Fig. 1 schematically illustrating in a longitudinal cross-sectional view, an alternate embodiment of the apparatus illustrating the ability of the apparatus to selectively hold and release a plurality of pump down means, such as a wiper assembly, ball, or the like.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Now, with reference to Fig. 1, there is shown an apparatus 100 for holding and mechanically releasing a pump down means used during the cementing of a conduit within a subterranean well. The apparatus 100 has at its uppermost end a longitudinally extending housing member lOla which receives at its uppermost ends at threads 102 the lower end of a kelly joint, or other swivel housing S.

The housing member lOla is secured at threads 103 to a central housing member 101b. A portion of the internal diameter of the housing member 101b is enlarged at 104, such enlargement 104 providing for receipt of an extension means, or head support 112 when it is shifted to released position to permit the plug P to be discharged through the apparatus 100, as detailed below.

When the head support 112 is within the opening 104a in the central housing member 101b, a head support tip 112a on the uppermost surface of the head support 112 and facing the nose P3 of the plug P, will be parallel to the smooth bore internal diameter 113 of the central housing member 101b, thus eliminating any interference between the head support 112 and movement of a cylindrical sleeve 106 carried interiorly of the housing members 101a and 101b.

The central housing member 101b has a transversely projecting bore 101d for threaded receipt of a lock pin member 115 by means of threads 114. The lock pin member 115, when in place to secure the sleeve 106 in a first position prior to release of the plug P, has a lock shoulder 115c profiled for companion interfacing with a similarly profiled shoulder 106a around the lowermost end of the sleeve 106. When the shoulders 106a, 115c are in engagement as shown in Fig. 1 the sleeve 106 is prevented from movement in one direction to activate the release of the plug P.

The lock pin 115 also has at its inboard tip end a release shoulder 115b angularly profiled such that a 180 rotation of the lock pin 115 by means of an insert of tubing (not shown) or the like through a rotation bore 115a at the outboard-most end of the lock pin 115 will cause the release shoulder 115b to be rotated and the lock shoulder 115c to come into mating alignment with the smooth bore 113 of the central housing member 101b. In such position, the sleeve 106 is permitted to move in one direction until the shoulder 106a interfaces with a stop shoulder 101c on the central housing member 101b.

At the lowermost end of the central housing member 101b is a pin portion having threads 105 for securement of the apparatus 100 to the uppermost end of a section of drill pipe C, or other conduit extendable into the subterranean well.

The plug P is inserted through the uppermost end of the apparatus 100 and is housed within the sleeve 106 with the nose tip P3 of the plug in abutting relationship to the head support tip 112a when the extension or head support 112 is placed across the sleeve 106.

As shown, the plug P is strictly conventional in nature and its particular construction does not form a part of the present invention. In lieu of the plug P, any number of pump down means may be inserted within the sleeve 106 for activation by the apparatus 100, such as balls, darts, and the like. As shown, the plug P has a circumferentially extending elastomeric O-ring element P1 for receiptwithin a receiving profile within the liner wiper plug bore of the well upon final passage of the plug P through the drill pipe C with ratchet threads P2 extending toward the nose P3 from the O-ring P1 for locking engagement of the plug P in its final and lowermost position.The plug P also has a series of outwardly extending cup-like elastomeric or flexible wiper cups P4, P5 which, when the plug P is in position in the apparatus 100 and sleeve 106, sealingly engage along the inner wall of the sleeve 106 to prevent fluid transmission across the plug P interior of the sleeve 106.

Because the plug P is in sealing securement relative to the sleeve 106 when in position as shown in Figs. 1, and, further, because of the interrelationship of the shoulders 115b, 115c between the lock pin 115 and the lowermost end of the sleeve 106, fluid is blocked from being transmitted through the sleeve 106 from the uppermost end of the apparatus 100 down to the string of casing C. However, there is provided between the housing members 101a, 101b, and the sleeve 106 a fluid flow annulus 107 which, at the uppermost end 108 of the sleeve 106 extends between a series of protruding guide elements 109 and initial flow passage portions 109a therebetween. The fluid flow passageway extends in the flow annulus 107 and passes through the sleeve 106 by means of flow port 110 to pass downwardly through the lowermost end of the apparatus 100 and into the drill pipe C.Accordingly, it will be appreciated that at all times while a plug P is within the sleeve 106, cementitious or other remedial fluid may be continually pumped through the apparatus 100 and drill pipe C.

The extension means or head support 112 is secured to the sleeve 106 exterior by means of a protruding hinge support 112c. A hinge pin 112b extends between the support 112c and through a bore in a head support arm 112e to secure the head support 112 in pivotal relationship with the sleeve 106.

In the position shown in Fig. 1, the outboard surface 112f of the arm 112e rests upon the internal diameter 113 of the central housing member 101b to position the head support 112 in extended position across the uppermost end of the plug P and prevents movement of the plug P within the sleeve 106.

The sleeve 106 also has a head support window 111 extending through its end adjacent the uppermost portion of the head support 112 to permit the head port 112 to pass therethrough for placement within the circular opening 104 of the central housing member 101b as the sleeve 106 is shifted to release the plug P.

OPERATION When it is desired to run a plug P into the well within the casing C, the apparatus 100 is threaded by tongs or otherwise at threads 105 to the drill pipe C and a kelly, swivel or other element S is generally affixed at the uppermost end thereof. The apparatus 100 now is in the position as shown in Fig. 1.

With the apparatus in position as shown in Fig. 1, cementitious or other remedial fluid may be introduced through the uppermost end of the apparatus 100 to pass through the flow passage 109a between the guide members 109 and into the flow annulus 107 around the exterior of the sleeve 106 and thence through the flow port 110 and downwardly into the drill pipe C. The position of the wiper cups P4, P5, relative to the internal diameter of the sleeve 106 will block fluid from passing across the plug P interior of the sleeve 106.

When it is desired to release the plug P, a release bolt (not shown) or other mechanical means is placed through the rotation bore 115a of the lock pin 115 to manipulate the lock pin 115 approximately 180 to permit the lock shoulder 115c to become aligned with the smooth bore 113. As the lock interface between the shoulders 115b, 115c is broken, and because of the pumping of the cementitious fluid (or weight of the sleeve 106 and plug P if fluid is not being pumped at that time), the sleeve 106 will be moved downwardly until further longitudinal movement is prevented by the interface of the stop shoulder 101c and the bevelled shoulder 106a.

As the sleeve 106 is moved downwardly, as described, the outboard surface 112f of the arm 112e will come into horizontal alignment with the circular opening 104 in the central housing member 101b and the plug P will be urged against the head support tip 112a to shift the head support 112 into the head support window 111 and into the opening 104 to completely move the head support 112 away from the plug P. As fluid pressure is continued (or pumping initiated, if not previously effected) the plug P is pumped through the sleeve 106 and the central housing member 10lib into the drill pipe C. The apparatus is now in the position as shown in Fig. 2.

Now with reference to Fig. 6, there is shown a configuration of the apparatus 100 wherein a series of plugs P and/or a plug P and ball B may be disposed within the apparatus 100 for introduction into the well through the drill pipe C, with a plurality of head support members 112 extending within the sleeve 106 for selective shifting into the openings 104 and window 111, respectively, as companion lock pins 115 are manipulated, in series, as described above.

Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.

Claims

CLAI MS: -

1. An apparatus for holding and mechanically releasing a pump down means used during the cementing of a conduit within a subterranean well, said apparatus being securable on a longitudinally and rotationally manipulatable conduit member communicating with said well, said apparatus comprising: (1) an elongate cylindrical housing; (2) a cylindrical sleeve concentrically disposed therein for receipt of said pump down means; (3) means for holding said sleeve in a first position and preventing movement of said sleeve relative to said housing in a first direction; (4) means for selectively releasing said sleeve from said first position to thereby permit movement of said sleeve relative to said housing;; (5) extension means provided within said sleeve and movable between first and second extension positions, said extension means when in one of said extension positions preventing movement of said pump down means in one direction and when in the other of said extension positions permitting passage of said pump down means through said apparatus; and (6) an annular cementing fluid transmission passageway defined between said housing and said sleeve and from one end of said apparatus to the other end of said apparatus.

2. An apparatus according to Claim 1 further comprising an opening in said housing for receipt of said extension means when said extension means is moved to said second extension position.

3. An apparatus according to Claim 1 or 2 further comprising: a hinge support on said cylindrical sleeve; and hinge means extending from said hinge support to said extension means and permitting pivotal movement of said extension means relative to said cylindrical sleeve.

4. An apparatus according to any preceding Claim 1, 2 or 3 wherein said means for holding said sleeve comprises a pin element projecting through said cylindrical housing and having a protruding profiled tip on an inboard end thereof for mating contact with a companion shoulder on said sleeve.

5. An apparatus according to any preceding Claim wherein said means for holding said sleeve comprises a threadably secured manually rotatable pin element projecting through said cylindrical housing and having a protruding profiled tip on the inboard end thereof for mating contact with a companion shoulder on said sleeve.

6. An apparatus according to any preceding Claim wherein said means for holding said sleeve comprises a pin element projecting through said cylindrical housing and having a protruding profiled tip on an inboard end thereof for mating contact with a companion shoulder on said sleeve, said profiled tip traversing an offset release shoulder rotationally alignable relative to said sleeve and said cylinder to release said holding means relative to said sleeve.

7. An apparatus according to any preceding Claim wherein said means for holding said sleeve comprises a pin element projecting through said cylindrical housing and having a protruding profiled tip on an inboard end thereof for mating contact with a companion shoulder on said sleeve, said profiled tip traversing an offset release shoulder rotationally alignable relative to said sleeve and said cylinder to release said holding means relative to said sleeve, whereby upon rotation of said pin element approximately 180, said offset release shoulder is in parallel alignment with said sleeve and said cylindrical housing.

8. An apparatus according to any preceding Claim wherein the pump down means is a liner wiper plug.

9. A method of mechanically releasing a pump down means used during the cementing of a conduit within a subterranean well while continuously pumping a cementitious fluid through said apparatus prior to, during and subsequent to said releasing, comprising the steps of: (a) assembling at the top of the well and below a rotational kelly joint an apparatus comprising:: (1) an elongate cylindrical housing; (2) a cylindrical sleeve concentrically disposed therein for receipt of said pump down means; (3) means for holding said sleeve in a first position and preventing movement of said sleeve relative to said housing in first direction; (4) means for selectively releasing said sleeve from said first position to thereby permit movement of said sleeve relative to said housing, (5) extension means within said sleeve and movable between first and second extension positions, said extension means when in one of said extension positions preventing movement of said pump down means in one direction and when in the other of said extension positions permitting passage of said pump down means through said apparatus;; (6) an annular cementing fluid transmission passageway defined between said housing and said sleeve and from one end of said apparatus to the other end of said apparatus; and (7) pump down means within said sleeve and being positioned to prevent longitudinal movement in one direction by said extension means, said pump down means being sealingly positioned relative to said cylindrical sleeve to prevent fluid flow from one end of said sleeve to the other end of said sleeve; (b) introducing a cementitious fluid through said apparatus and within said annular cement fluid transmission passageway; and (c) moving said extension means from said first extension position to said second extension position to thereby permit said cementitious fluid to shift said cylindrical sleeve to a second position and move said extension means to the other of said extension positions to permit passage of said pump down means through said apparatus with said cementitious fluid flow.