US2509469A - Well tool thread lock - Google Patents

Description

May 30, 1950 A. A. BAKER WELL TOOL THREAD LOCK Filed Sept. 29. 1947 F16, F162 v INVENTOR. 4mm 4. Eater W ffi Z J W ATTOE/VFYF Patented May 30, 1950 UNITED STATES PATENT OFFICE WELL TOOL THREAD LOCK Aaron A. Baker, Coalinga, (lalifl, assignor to Baker Oil Tools, Inc., Vernon, Calif., a corporation of California Claims.

The present invention pertains to well devices, such as well packer apparatus utilized in the bridging, cementing, acidizing and testing of well bores, as well as in other operations.

In the accomplishment of certain purposes in a well bore, several interconnected tools, or several interconnected components of a single tool, are run in a well bore on a single running-in string and are controlled by manipulating the latter member. It may be desired to first move or operate one of the tools or components without moving the other and then move or operate the latter. As an example, a lower tool may be attached to an upper tool through a left hand threaded connection and the upper tool may be secured to a tubing string by another left hand threaded connection, or through a J type of pinand-slot look. It is desired to perform an operation by turning the tubing string and threading or relatively moving the parts of one of the connections without fear of also threading or relatively moving the other connection. Thereafter, one tool is to be disconnected from the other tool by unscrewing the other connection through rotation of the tubular string.

An object of the invention is to provide an improved lock device for one of the aforesaid connections, which will insure against relative movement of its component parts until desired.

Another object of the invention is to provide an improved lock device for a threaded connection which precludes inadvertent relative threading movement between the component parts of the connection.

This invention has other objects which will become apparent from a consideration of the embodiment shown in the drawings accompanying and forming part of the present specification. This form will now be described in detail to illustrate the general principles of the invention, but it is to be understood that such detailed description is not to be taken in a limited sense, since the scope of the invention is best defined by the claims appended hereto.

Referring to the drawings:

Fig. 1 is a longitudinal section through a device incorporating the present invention, disclosing its parts in one relative position.

Fig. 2 is a view similar to Fig. 1 disclosing the device with the upper connection partially rotated.

Fig. 3 is a view similar to Fig. 1, with parts of the lower connection unthreaded from one another.

Fig. 4 is a cross-section taken along the line 4-4 in Fig. .1.

As disclosed in the drawing, the invention has been applied to a well packer A and bridging device B, which are interconnected with one another and are usually lowered through a string of casing C on the lower end of a suitable tubular string D, such as tubing or drill pipe, to the desired point at which the packer is to be anchored to the casing in packed-off condition. The well packer A may be of any suitable construction, the one shown being of the type specifically described in United States Letters Patent No. 2,121,051.

Essentially, the packer consists of a tubular body 50 to which the lower end of the bridging device is secured. The body has a packing sleeve ll surrounding it, whose upper and lower ends are suitably secured, respectively, to upper and lower conical expanders I2, l3 attached to the body originally by one or more shear screws M. The outer surface of the upper expander I2 tapers upwardly and inwardly and is engaged by correspondingly tapered upper segmental slips 15 secured to it originally in retracted position by shear screws l6. Similarly, the outer surface of the lower expander i3 is tapered inwardly in a downward direction and engages correspondingly tapered lower segmental slips ll secured to it originally in retracted position by shear screws it. The upper end of the body carries an abutment ring l9, and the lower end of the body is provided with a lower abutment 20 for engagement with the lower end of the lower segmental slips ll.

A valve housing and guide 2| is secured to the lower end of the body It and has a back pressure ball 22, preferably buoyant in cement slurry, engageable with its companion valve seat 23 on the body. As described in detail in the above identified patent, the ball valve 22 is held orige inally in ineffective position to one side of the valve housing 2!, but this element is releasable during the setting operation of the well packer in a well casing. Such setting operation occurs as a result of dropping a trip valve ball (not shown) down through the tubing string D in a known manner, as explained fully in the aforementioned Patent No. 2,121,051.

As aforementioned, the bridging ball retaining and releasing device B is suitably secured to the upper end of the well packer. Specifically, this device consists of a bridging ball housing 24 threaded into the upper end of the body It by means of a left hand threaded connection 25, 26. For convenience of manufacture, the housing 24 86 is made in two parts 21, 28, its lower sub 21 being attached to the packer body l0 through the left hand threaded interconnection 25, 26. The housing is provided with an enlarged medial chamber 29 in which a bridging ball 3!], or corresponding valve element, may be confined. The bridging ball, when released, may drop downwardly a comparatively short distance, under gravitational influence, through the lower tubular sub 21 and into engagement with a valve seat 3! provided in the upper end of the packer body It].

The bridging ball 38 is held initially against the inner wall of the chamber 25 to one side of the central passage through the apparatus by a retainer sub 32. This sub is threaded into the upper end 28 of the housing 2 3, preferably through the use of a left hand threaded connection 33, 34, and has a depending tubular segment 35 integral therewith adapted to engage the bridging ball 36 and prevent its dropping downwardly onto the valve seat 3! in the packer body. It is to be noted that the finger or segment 35 engages the ball and holds it in the chamber 29, since the distance between the lower end of the segment and the lower downwardly and inwardly tapered wall 29a of the chamber is less than the diameter of the ball, thereby precluding dropping of the latter to its bridging position across the packer passageway ltd.

Rotation of the tubing string D, as to the right, causes unthreading of the retainer sub 32 from the housing 23 and elevates its segment 35 from confining engagement with the bridging ball 33, until the distance between the segment and the tapered wall 29a of the chamber is greater than the diameter of the ball, which then allows the latter to drop downwardly through the lower sub 27 and onto the bridging ball valve seat 3 l, closing the central passage lEla of the packer against downward flow of fluent substances (see Fig. 2).

The apparatus is made up as disclosed in Fig. 1, with the retainer sub 32 threaded downwardly into the bridging ball housing 2 to its fullest extent to confine the bridging ball 33, the housing sub itself being threaded into the upper end of the body it of the well packer (see Fig. 1). As assurance against unscrewing of the lower sub 21 from the packer Preparatory to upward unthreading of the retainer sub 32 from the housing 24, the lower sub 21 may be prevented from rotating originally by a loclr device E eiTecting a connection between the lower sub 2'! and the body Ill of the well packer A.

The lock device E consists of a shear pin 35 extending substantially parallel to the axis of the apparatus into the trip or abutment ring l9 attached to the upper end of the packer body. The shear pin 35 extends into an outer eccentric member 33 having a circular bore 31 eccentric to the axis of the apparatus and an inturned flange 38 disposed immediately above an external flange 39 on the lower sub 21. A companion inner eccentric member 45 is located within the outer member 36 with its outer shoulder M engaging the upper end of the latter. The inner member 4!! is secured to the lower sub 21 by a set screw 42, which need bear but lightly thereagainst.

The inner eccentric member l!) makes a substantially sliding fit with the lower sub 2?, and also fits within the outer eccentric member 36 in such fashion as to prevent rotation therebetween, in View of the eccentricity of the two members with respect to the lower sub 2'5. The inner member 40 actually engages the lower sub frictionally, so that any tendency for the lower sub to rotate also rotates the inner eccentric member 4!] with it frictionally, such rotation being transferred to the outer eccentric member 36 and through the shear pin 35 and abutment ring 19 to the tubular body [ll of the packer A. As assurance that the inner eccentric member 2-3 will rotate the lower sub 21, the set screw 52 is provided, the lower sub carrying the inner eccentric member around with it, and through its eccentric coupling with the outer eccentric member 36 transmitting the torque from the lower sub 21 through the shear pin 35 to the tubular body Hi.

It is evident from the lock device described that relative rotation between the lower sub 2? and tubular packer body [0 cannot occur until the shear pin 35 has been disrupted. Suiflcient torque is not applied to thus shear the pin until it is purposely desired to unthread the lower sub 2? from the tubular packer body H1 and remove the tubing string D, bridging ball device B and lock device E to the top of the well bore. 7

The operation of the device will be understood in connection with a typical use of the apparatus. The apparatus is assembled as disclosed in Fig. 1, with the ball 30 confined in the chamber 29 by the depending arm or segment 35. When in this position, the retainer sub 32 is threaded downwardly to substantially its fullest extent, spacing an upper external flange or shoulder 43 on the retainer sub downwardly with respect to an inturned flange or shoulder 43 on a stop ring 45 threaded on the housing 24. Leakage between the parts is prevented by the provisions of suitable side seals 45 on the stop ring 45 and housing 24, which slidably engage the retainer sub 32. The lower sub portion 2i of the housing is also fully threadedly connected with the tubular body it], and the shear pin 35 of the lock device E is installed in place, as well as the other eccentric elements 36, 4!] of the lock portion of the apparatus.

The tool is lowered in the well bore and the packer anchored in place with its slips l5, ll engaging the casing C and the packing sleeve I I providing a firm seal between the packer body If! and wall of the casing. In setting the well packer, the tripping ball (not shown) passes down through the tubing string D and bridging ball device B around the bridging ball 30, and completely through the apparatus, releasing the buoyant ball valve 22 from its original ineffective position within the valve housing 2! (in a known manner), allowing it to move upwardly into engagement with its companion seat 23.

After anchoring of the casing in packed off conditions, cement slurry or other fluid may be pumped through the tubing string D and apparatus B, A for discharge from the lower end of the packer. The bleeding ofi of pressure within the tubing string allows the back pressure ball 22 to move upwardly and engage its companion seat 23, preventing return or upward flow of fluid through the packer apparatus A.

When it is desired to prevent downward passage of fluent substances through the packer apparatus A, the tubular string D is rotated to the right to unthread the retainer sub 32 in an upward direction from the housing 24, in view of the left hand threaded connection 33, 34, elevating the attached retainer finger or segmentl35 from engagement with the bridging ball 30 and allowing the latter to gravitate into engagement with its companion seat 3! on the upper portion of the packer body Ill. The bridging ball thus prevents downward passage of fluid through the well packer A, and since the back pressure valve member 22 prevents upward passage of fluid through the .apparatus, a bridging packer is provided which prevents flow of fluids through the apparatus in both directions.

As indicated above, the lock device E is provided to insure against unthreading of the left hand threaded connection 25, 2% between the lower sub member 27 of the bridging ball housing 24 and the tubular body it, insuring that the initial right hand rotation of the tubular string D will cause unthreading of the retainer sub 32 upwardly with respect to the bridging valve housing 24, in order to release the bridging ball 30. Any torque incident to such rotation of the tubing string D, imposed upon the bridging ball housing 24, is transmitted through the lock device E and its shear pin 35 directly to the tubular body 10, very little, if any, of such torque being imposed upon the lower left hand threads 25, 26, thus precluding their inadvertent unscrewing.

Torque imposed upon the lower sub 2! of the housing 24 tends to rotate the inner eccentric member All with it. Since the inner eccentric member tends to move within the outer eccentric member 36, it is shifted laterally into firmer frictional engagement with the lower sub 21, thus locking the latter and the inner eccentric member Ml securely together. As indicated, the eccentric disposition of the inner member 40 within the outer member 35 prevents relative rotation between the two parts, the torque on the lower sub 21 being transmitted through the outer eccentric member 36 and through the shear pin 35 and abutment ring ill to the tubular body ill, which is prevented from rotating by the anchoring of the slips I5, I! in the casing C. Accordingly, as indicated above, the lower left hand threaded connection 25, 26 is substantially free from the imposition of torque, upon the initial rotation of the tubing string D and retainer sub 32 to elevate the latter and release the bridging ball 3! for dropping onto the upper valve seat 3!.

After the bridging ball has engaged its seat, the tubing string D may be rotated to the right to a further extent, correspondingly rotating the retainer sub 32 and elevating it with respect to the housing 24 until its external flange 43 abuts the inturned flange or shoulder 44 on the stop ring 45. Such abutting prevents further relative rotation between the sub 32 and housing 2c in a right hand direction. Thereafter, an increase in the torque imposed upon the tubing string D causes the retainer sub 32 and bridging ball housing 24, including the lower sub 21 on the latter, to rotate as a unit, this torque being transmitted through the inner and outer eccentric members fill, 36 to the shear pin 35. Since the tubular body It and its abutment ring l9 are prevented from rotating by the slips I5, ll, an increase in the torque on the tubing string D to a sufficient extent shears the pin 35 and allows the tubing string, retainer sub 32 and bridging ball housing 24 to be rotated in a right hand direction to unscrew the lower sub 2] completely from the well packer body l0, permitting withdrawal of the entire apparatus, with the exception of the well packer A, to the top of the well bore (see Fig. 3). The bridging ball 3d, of course, remains on its seat 3| to prevent passage of fluid in both directions through the well packer A in conjunction with the buoyant back pressure valve ball 22 at the lower end of the well packer.

It is, accordingly, apparent, that a lock device has been provided which precludes disconnection between the upper and lower portions of the apparatus until desired, assuring the proper movement of the upper portion of the apparatus, as in releasing the bridging ball 30 from the chamber, prior to shearing of the pin 35. Although described in connection with the bridging ball releasing arrangement, it is to be understood that the lock device has a general application in-preventing inadvertent disconnection or relative movement between members in general.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In apparatus of the character described, in cluding a pair of relatively rotatable members threadedly connected together, separate annular means rotatable with one of said members and removably mounted on said one member, and frangible means connecting said means with said. other member.

2. In apparatus of the character described, including a pair of relatively rotatable members connected together, separate annular means movable with one of said member and removably mounted on said one member, and frangible means connecting said means with said other member.

3. In apparatus of the character described, including a pair of relatively movable members threadedly connected together, an inner eccentric on one of said members, an outer eccentric on said inner eccentric, and frangible means connecting said outer eccentric with said other member.

4. In apparatus of the character described, including a pair of relatively movable members threadedly connected together, a first eccentric member rotatable with one of said members, a second eccentric member companion to said first eccentric member and engageable therewith, and frangible means connecting said second eccentric member with said other relatively movable memher.

5. In apparatus of the character described, including a pair of relatively movable tubular members threadedly connected together, a first eccentric member rotatable with one of said members, a second eccentric member companion to and engageable with said first eccentric member, and frangible means connecting said second eccentric member :with said other tubular member.

6. In apparatus of the character described, including a pair of relatively movable tubular members threadedly connected together, a first eccentric member rotatable with one of said members, a second eccentric member companion to and engageable with said first eccentric member, and releasable means connecting said second eccentric member with said other tubular member.

7. Well apparatus, including a well packer having a tubular body, a tubular member threadedly connected to said body, a first eccentric rotatable with said member, a second eccentric companion to and engageable with said first eccentric, and frangible means connecting said second eccentric with said tubular body.

8. Well apparatus, including a well packer having a tubular body, a tubular member threadedly connected to said body, an inner eccentric frictionally engageable with said member, a companion outer eccentric encompassing said inner eccentric, and frangible means connecting said outer eccentric with said body.

r 9. Well apparatus, including a well packer having a tubular body, a tubular member threadedly connected to said body, an inner eccentric frictionally engageable with said member, a set screw threaded in said inner eccentric and engaging said tubular member, a companion outer eccentric encompassing said inner eccentric, and frangible means connecting said outer eccentric with said body.

10. In apparatus of the character described, an 10 Number outer tubular member, an inner tubular member threadedly and detachably connected to said outer member, a first eccentric member rotatable with said inner member, a second eccentric member companion to and engageable with said first eccentric member, and releasable means connecting said second eccentric member with said outer tubular member.

AARON A. BAKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 1,243,364 Walker Oct. 16, 1917 FOREIGN PATENTS Number Country Date 28,929 Great Britain Dec. 16, 1912

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