Latch-in adapter

Abstract

An improved latch-in adapter to be used in conjunction with a latch-in receiver, the latch-in adapter to be mounted with a pipe string in a well bore for downhole latching, the latch-in adapter having an inner mandrel, latch means on the mandrel for engaging the latch-in receiver, connection means for connecting the latch means with the mandrel for transmitting movements of the mandrel to the latch means in several selected positions, and lock means on the mandrel and movable longitudinally therewith for engaging the latch means to prevent upward longitudinal movement of the mandrel when an upward longitudinal force is imposed upon the mandrel sufficient to otherwise release the latch means.

Description

BACKGROUND OF THE INVENTION

The field of this invention relates to latching devices for tubular members, and particularly to downhole latch-in adapters and receivers suitable for use in cementing operations and the like.

Prior art latch-in adapters include those having sealed connections maintained merely by the weight of the drill pipe and used to direct cement through the drill pipe to the annular area around the casing. Other latch-in adapters have threaded latching mechanisms, some of which suffer from the disadvantage of requiring removal of the entire pipe string after it has been locked and released before reengagement of the latch-in adapter with the latch-in receiver, while others require excessive undesirable rotation of the drill pipe to release latching mechanism.

SUMMARY OF THE INVENTION

The present invention provides a new and improved latch-in adapter for latching of a pipe string to a latch-in receiver, wherein the latch-in adapter has an inner mandrel having a latch means therewith for latching engagement with the latch-in receiver, and a connection means for connecting the latch means with the mandrel for longitudinal movement therebetween to transmit movement of the mandrel to the latch means in selected positions, and a lock means mounted with the mandrel and movable longitudinally therewith for engagement with the latch means to prevent upward longitudinal movement of the mandrel when subjected to an upward longitudinal force sufficient to otherwise release the latch means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view showing the latch-in adapter of the present invention as used in a drill string with a cement shoe;

FIG. 2 is an elevational view of the latch-in adapter in an unlocked position;

FIG. 3 is an elevational view of the latch-in adapter of the present invention in a locked position with the latch-in receiver; and

FIG. 4 is an elevational view of the latch-in adapter of the present invention in position for removing the latch-in adapter from the latch-in receiver.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the drawings, the letter A designates the latch-in adapter of the present invention which as shown in FIG. 1 is incorporated in a cementing assembly disposed within a well bore W and extending to the surface of the well. The latch-in adapter A as received by latch-in receiver R includes a mandrel M having a lock means L therewith, and a latch means P connected to the mandrel M by connection means C. Unless otherwise noted, the components of this invention are made of steel, iron or other materials capable of taking relatively heavy stresses and strains for preventing structural failure.

Considering the invention in more detail as shown in FIG. 1, the latch-in adapter A and the latch-in receiver R are disposed within a well bore W. A casing hanger 10 is located at the surface of the well bore W and is capable of being attached to and threadedly engaging casing 12 adjacent threaded portion 10a of the casing hanger 10 at threaded portion 12a of the casing 12. A guide shoe 14 is in threaded engagement at portion 14a with the lower threaded portion 12b of the casing 12, the guide shoe 14 being useful in orienting the casing 12 within the well bore W.

A pipe string 16 having a bore 16b extending therethrough, is disposed within the casing 14 within the well bore W. An annular mounting member or a tubular joining member 18 having a bore 18b therethrough and in matching axial alignment with bore 16b of the pipe string 16, threadedly engages the pipe string 16 at threaded end portion 16a with threaded end portion 18a of the tubular joining member 18. The latch-in adapter A is mounted with the tubular joining member 18. The latch-in adapter A is adapted to be received by latch-in receiver R which is mounted with a receptacle 20 as shown in FIG. 1. A spherical back pressure valve 22 is mounted adjacent with the receptacle 20 in the guide shoe 14.

As shown in FIG. 2, the mandrel M of the latch-in adapter A includes lock means L therewith, the mandrel M being joined to the latch means P by connection means C. The mandrel M includes an inner mandrel 24 having threads 24a adjacent its upper end for mounting the mandrel 24 with threads 18a of the tubular joining member 18. The tubular joining member 18 has an annular recess 18c disposed adjacent to threaded portion 18a for receiving an O-ring 26. The O-ring 26 promotes sealable engagement between the tubular joining member 18 at annular surface 24b of the inner mandrel 24 for preventing unwanted fluid migration therebetween. An opening 18d is formed in the tubular joining member 18 providing suitable mounting for a threaded locking bolt 28 which lockably engages surface 24c of the mandrel 24 to prevent relative rotational motion therebetween. Bore 24d extends therethrough the mandrel 24 and is in axial alignment with bore 18b of the tubular joining member 18.

The lock means L includes the annular Collett locking collar 30 having a latch-in surface 30a and a seating surface 30b which is discussed more fully hereinbelow.

A plurality of annular recesses 24f are disposed adjacent end portion 24e of the mandrel 24 for mounting seal rings 32 therewith. The seal rings 32 are to sealably engage inner bore 20a of the receptacle 20 to inhibit unwanted migration of fluid therebetween.

The mandrel M is connected by the connection means C to the latch means P. The connection means C includes a pin 34 and a J-slot 36 formed in sleeve member 38. The sleeve member 38 is slidably mounted with the mandrel 24 adjacent central surface 24g of the mandrel 24. The latch means P includes a plurality of articulated, resilient fingers 40 formed with the sleeve member 38. Each of the resilient fingers 40 has an inner face or surface 40a, a beveled face or surface 40b, outer faces or surfaces 40c, 40d, 40e, surface 40f, and longitudinally extending portion 40g. The fingers 40 are capable of resilient radially inward movement such that each finger 40 yields about longitudinally extending portions 40g in response to inward urging as will be discussed in full detail hereinbelow.

The latch-in receiver R is adapted to be mounted with the receptacle 20 and includes an annular receiver member 42 adapted to be mounted adjacent annular surface 20b of the receptacle 20. Suitable openings 20c, 42a are formed respectively in the receptacle 20 and receiver member 42 to accommodate a shear pin 44 which releasably locks the receptacle 20 and the receiver member 42 together to prevent relative longitudinal and rotational motion therebetween until an upward pull is exerted which is substantially in excess of the normal upward force exerted thereon for the release of the latch means P from the receiver R. As shown in FIG. 4, the receiver member 42 includes surfaces 42b, 42c, 42d, 42e, 42f, 42g, 42h, and 42i which are described more fully hereinbelow. As noted above, the receiver member 42 is mounted with surface 20b of the receptacle 20 adjacent to surface 42h of the receiver member 42. In this position, surface 20d of the receptacle 20 is engagement with surface 42g of the receiver member 42. Furthermore, surface 42i of the receiver member 42 is in conical alignment with surface 20d of the receptacle 20 and adapted to receive corresponding surface 18e of the tubular joining member 18 (FIG. 4).

In the use or operation of the form of the invention illustrated in FIGS. 1-4, after a well bore W is drilled, the casing 12 (FIG. 1) is supported at its upper end by the casing hanger 10 and is threadedly affixed at its lower end to the guide shoe 14 having the receptacle 20 and receiver member 42 mounted therewith. The pipe string 16 having the tubular joining member 18 mounted therewith and being in threaded engagement with the mandrel 24 is lowered within the interior of the casing 12. As this assembly approaches the guide shoe 14, the end portion 24e of the mandrel 24 is guided into annular surface 42b (FIGS. 3, 4) by the aligned conical surfaces 14b (FIG. 1) of guide shoe 14, surface 20d of receptable 20, and surface 42i of receiver member 42. With annular surface 42b (FIGS. 3, 4) being of a larger diameter than inner bore 20a of the receptacle 20, the risk of damage to seal rings 32 mounted with the mandrel 24 is minimal as end portion 24e of the mandrel 24 is lowered through the opening designated by surface 42b. Conical surface 20e of the receptacle 20 provides further alignment of the mandrel 24 with inner bore 20a to thus insure proper seating and engagement of the seal rings 32 with the inner bore 20a of the receptacle 20.

During the installation procedure of the latch-in adapter A, the pin 34 is positioned in the J-slot 36 as designated in FIG. 2; for as the end portion 24e of the mandrel 24 is lowered into bore 20a of the receptacle 20, beveled face or surface 40b of the fingers 40 contacts surface 42i of the receiver member 42 causing the sleeve 30a to remain stationary as the pipe string 16, tubular joining member 18, and mandrel 24 move downwardly. Thus, the sleeve 38 remains stationary with respect to the downward movement of the mandrel 24 during insertion of the latch-in adapter A into the latch-in receiver R until annular shoulder 18f contacts end portion 38a of the sleeve member 38.

When surfaces 18f, 38a contact, surface 40b no longer rests upon surface 42i for the sleeve 38 no longer slides relative to the mandrel 24. With the sleeve 38 and the joining member 18 in such an engaged configuration, further lowering of the pipe string 16 causes yielding of the fingers 40 radially inwardly as surface 40b of the resilient fingers 40 is forced into the annular surface 42b of the receiver member 42. Further downward movement causes surface 40c of fingers 40 to move longitudinally downwardly adjacent surface 42b of the receiver member 42 until lip or surface 42c of the receiver member is passed by surface 40c of the fingers 40, whereinafter surface 40c contacts surface 42d of the receiver member 42. In this position, surfaces 40e, 40c of the fingers 40 are adjacent surfaces 42b, 42d, respectively, of the receiver member 42. It will be appreciated that the overall diameter of outer surface 30c of the locking collar 30 is less than that associated with the surface 42b of the receiver member 42, thus imposing no difficulties in inserting the mandrel-locking collar assembly therethrough surface 42b.

With the pin 34 adjacent portion 36a of J-slot 36, the mandrel 24 may be fully inserted into the receiver member 42 noting that the lowermost position of the mandrel 24 with respect to the receiver member 42 and the receptacle 20 is limited by surface 18e of the tubular joining member 18 contacting surfaces 42i, 20d of the receiver member 42 and and the receptacle 20, respectively. It will be appreciated that in this lowermost position, surface 30b of the locking collar 30 does not contact surface 20e of the receptacle 20 and surface 40c of the resilient fingers 40 is adjacent surface 42d of the receiver member 42, noting that surface 40b will not contact surface 42e.

In this lowermost position as noted in FIG. 2, with pin 34 adjacent portion 36a of J-slot 36, normal cementing operations may take place. As is well known, cement is pumped through the bore 16b of the pipe string 16, the bore 18b of the tubular joining member 18, through bore 24d of mandrel 24 into bore 20f of the receptacle 20, beyond the back pressure valve 22, and out from the guide shoe 14 to fill the void between the outer wall of the casing 12 and the well bore W. During normal pumping operations, significant pressure concentrations arise which tend to separate the pipe string 16 from the receptacle 20. In the event of normal fluctuations of pressure, pin 34 being mounted with the mandrel 24 is free to move reciprocally adjacent surface 36b of the J-slot 36 without any adverse consequences, such as disconnection of the pipe string 16 from the receptacle 20.

In the event of significant back pressure exerted upon the mandrel 24, the latch-in adapter A is prevented from disengagement with the latch-in receiver R when the lock means L engages the latch means P thus latchably engaging the latch-in receiver R. More specifically, an upward longitudinal force on the mandrel 24, having the locking collar 30 and pin 34 therewith, causes upward motion of the same relative to the sleeve 38. The sleeve 38 is restrained in position by surface 40d of the resilient fingers 40 being held by surface 42c of the receiver member 42. However, as the pin 34 sliding along portion 36b approaches portion 36c of the J-slot 36 (FIG. 3), the locking collar 30 engages the resilient fingers 40 with surfaces 30a contacting inner face or surface 40a. In this position, the fingers 40 are unable to resiliently yield, resulting in lockable engagement of surfaces of 42b, 42c, 42d of the receiver member 42 and surfaces 40c, 40d, 40e of the articulated fingers 40. In this latched configuration, note particularly that seal rings 32 remain sealably engaged with inner bore 20a of the receptacle 20. Furthermore, in this latched configuration, surface 18e of the tubular joining member 18 no longer engages conically aligned surfaces 20d, 42i. Also, pin 34 nears, but does not touch portion 36c of the J-slot 36 thereby preventing unwanted stress concentrations and potential shearing of the pin 34 under such extreme pressure conditions.

When the extreme pressure forces hereinabove mentioned subside, the mandrel 24 returns to the position as shown in FIG. 2 due to the magnitude of the weight of pipe string 16 upon the mandrel 24.

Should it be desired to remove the mandrel 24 from the latch-in receiver R, it is necessary for the entire pipe string 16 to be rotated in a clockwise direction (a counterclockwise direction if the J-slot is reversed) and lifted with the pin 34 riding on portion 36g of the J-slot 36 until portion 36f is reached. With further upward removal force exerted upon the pipe string 16, the pin 34 remains in the position illustrated in FIG. 4 and defined as adjacent portions 36e, 36f, and 36g of the J-slot 36. In such a position, the sleeve 38 is fixed with respect to the mandrel 24, thus preventing locking collar 30 to lockingly engage the fingers 40 into latching engagement with the receiver member 42 as in FIG. 3. Thus, upward urging of the pipe string 16 acts upon tubular joining member 18, is transmitted through the mandrel 24 and the pin 34 to the J-slot 36 formed in sleeve member 38. Such upward urging of the sleeve member 38 results in surface 40d of fingers 40 contacting surface 42c of receptacle 42 with the fingers 40 yieldably moving in a radially inward direction in response to the upward urging. The action of surfaces 40d, 42c causes an inward compression of the fingers 40 until surface 40c contacts surface 42b of the receiver member 42 which limits the radially inward yielding of the articulated fingers 40. Continued upward urging results in the fingers 40 being removed from the annular surface 42b, effectuating a disconnect configuration. Thereafter, the end portion 24e of the mandrel 24 may be removed from the receptacle 20 and the receiver member 42 by the reverse of the above described inserting procedures.

Thus, the present invention embodies a latch-in adapter A adapted to be received by a latch-in receiver R which under conditions of excess stress prevents unwanted uncoupling of the latch-in adapter A and the latch-in receiver R. On the other hand, when it is desired to remove the latch-in adapter A from the latch-in receiver R simple upward rotation of the pipe string relative to the sleeve 38 results in an uncoupled positioning (FIG. 4) such that the latch-in adapter A may be removed from the latch-in receiver R without locking thereof. Furthermore, once uncoupled the procedure may be repeated numerous times without necessitating removal of the entire pipe string 16; for when the mandrel 24 is reinserted into the receiver member 42, surface 40b of fingers 40 rests upon surface 42i of receiver member 42 while pin 34 moves from portion 36f to portion 36a of J-slot 36 upon rotation of sleeve 38. Further reinsertion parallels the hereinabove described action associated with FIG. 2.

It will be appreciated that the present invention could alternatively be used for a downhole safety valve or for anchoring seal nipples in production packers.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

Claims

I claim:

1. In combination with a latch-in adapter and a latch-in receiver of the type adapted to be mounted with a pipe string in a well bore for downhole latching, the improvement residing in the latch-in adapter which comprises:

an inner mandrel having a bore therethrough, through which fluid may flow;

a latch means on said mandrel for latching engagement with the latch-in receiver;

connection means for connecting said latch means with said mandrel for longitudinal and rotational movements therebetween to transmit movements of said mandrel to said latch means in a running-in position and in a released position;

a lock means on said mandrel and movable longitudinally therewith for engagement with said latch means in a locking position to prevent upward longitudinal movement of said mandrel; and

said connection means including means operable after rotational movement of said mandrel relative to said latch means for positioning said lock means in the released position out of engagement with said latch means, and for thereafter preventing relative longitudinal movement between said latch means and said lock means to hold same in the released position when moving said mandrel upwardly.

2. The structure of claim 1, wherein:

said connection means connects said latch means with said mandrel for longitudinal movement of said mandrel upwardly relative to said latch means for moving said lock means into the locking position with said latch means.

3. The structure of claim 1, wherein:

said connection means includes means for returning said latch means and said lock means to the running-in position for re-setting said latch means in the locking position after rotational movement of said mandrel relative to said latch means.

4. The structure of claim 1, wherein said connection means includes:

means for permitting downward movement of said lock means relative to said latch means to move said lock means from the locking position by releasing said lock means from locking engagement with said latch means.

5. The structure of claim 1, wherein said connection means, includes:

a pin mounted with said mandrel; and

said latch means having a slot of a substantially J configuration therewith adapted to slidably receive said pin.

6. The structure of claim 1, further including:

sealing means on said mandrel for sealing with the latch-in receiver for inhibiting migration of fluid therebetween.

7. The structure of claim 1, wherein:

said lock means is fixed with and non-movable relative to said mandrel to prevent release of said latch means when pulling upwardly on the mandrel in the locked position.

8. The structure of claim 7, wherein said lock means includes:

an annular ring formed with said mandrel for engaging said latch means to lock said mandrel with the latch-in receiver.

9. The structure set forth in claim 8, including:

annular mounting member for sealably engaging said mandrel and for seating on said latch-in receiver.

10. The structure of claim 1, wherein said latch means includes:

means for yieldably engaging the latch-in receiver.

11. The structure of claim 10, wherein said yieldably engaging means includes:

a plurality of longitudinally extending, resilient fingers for engaging the latch-in receiver.

12. The structure of claim 11, wherein each of said fingers includes:

an inner face for engagement by said lock means when said lock means is in the locking position; and

an outer face for engaging the latch-in receiver.

13. The structure of claim 12, wherein each of said fingers includes:

a beveled face on said finger for facilitating insertion of said latch means in the latch-in receiver.

14. The structure of claim 12, wherein the latch-in receiver further includes:

an annular shoulder for engaging said outer face of each of said fingers during the latching engagement of said latch means with the latch-in receiver.