US2332749A

US2332749A - Tubing anchor

Info

Publication number: US2332749A
Application number: US450516A
Authority: US
Inventors: John S Page
Original assignee: BETTY LEE MCLAUGHLIN
Current assignee: BETTY LEE MCLAUGHLIN
Priority date: 1942-07-11
Filing date: 1942-07-11
Publication date: 1943-10-26
Anticipated expiration: 1960-10-26

Description

PAGE

TUBING ANCHOR Filed July 11, 1942 H/JA To may Inventor dorm 5. PAGE Patented Oct. 26, 1943 2,332,749 TUBING ANCHOR John S. Page, Long Beach, Calif., assignor of onetenth to Betty Lee McLaughlin, Los Angeles,

Calif.

Application duly ll, 19d2,$erial No. M0516 V M (Claims.

This invention has to do with well equipment and has more particular reference to tubing anchors. A general object of this invention is to provide a simple, practical and very efiective tubing anchor.

When an oil well or the like is equipped with a pump it is customary to install a string of tubing in the well to carry the pumped fluid to the ground surface and to arrange the pump at the lower end of this tubing. The long string of tubing has substantial flexibility and elasticity and during operation of the pump the tubing works up and down. This working of the tubing is caused by movement of the fluid column within the tubing, by the friction between the relatively reciprocable pump plunger and pump barrel and by the alternate imposition and relieving of the weight of the fluid column on the pump, which accompanies the pump-operating movements of the pump rod. The movement or working of the tubing produces wear between the tubing and the well casing and often causes holes to be worn in the casing and also wears the couplings of the tubing string so that they leak and sometimes fail.

Another object of this invention is to provide a tubing anchor that efiectively prevents working of the tubing.

Another object of this invention is to provide a tubing anchor that serves to maintain the tubing under tension or in a stretched condition so that it cannot stretch further and cannot contract during the pumping operations. When a conventional tubing anchor is used the tubing is relieved of a portion of its weight there by causing slack in the tubing and allowing the above described working of the tubing. Where the tubing anchor of the present invention is employed the tubing is held under tension so that there is no slack and no possibility for the tubing to work.

Another object of this invention is to provide a tubing anchor that is actuated and held actuated by the head or hydrostatic pressure of the column of fluid in the tubing and that is released or conditioned for ready release when the fluid column is drained from the tubing. No manipulation of the tubing string is required for either the operation or the release of the anchor of this invention. The operation of the anchor is entirely automatic and the tubing need not be disturbed to control or operate the anchor.

Another object of this invention is to provide a tubing anchor that is positive in operation and that remains positive and effective so long as the fluid column occupies the tubing string.

Another object of this invention is to provide a tubing anchor of the character referred to that is extremely simple in construction and that is not subject to becoming "sanded up or made inoperative by accumulations of sand.

A further object of this invention is to provide a tubing anchor of the character mentioned that does not restrict or in any way interfere with the movement of fluid through the tubing and that may be interposed in the tubing string at any selected point or points without necessitating alteration of the tubing string assembly.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of my invention, throughout which description reference is made to the accompanying drawing, in which:

Fig. 1 is a side elevation of the improved anchor of this invention in position in the well tubing prior to actuation. Fig. 2 is an enlarged longitudinal detailed sectional View taken substantially as indicated byline 22 on Fig. 1, showing the anchor in the actuated condition and Figs. 3, 4 and 5 are transverse detailed sectional views taken as indicated by the line 3--3, 4-4 and 5--5, respectively, on Fig. '2.

In the drawing, C designates the well casing and T designates a portion of the well tubing extending through the casing. It will be assumed that the tubing T extends from the well pump, not shown, to the top of the well where it may be secured to the usual tubing head. The anchor of the invention may be connected in the string of well tubing T at any selected or desired point and, if desired, two or more of the anchors may be incorporated in the tubing string at vertically spaced points.

The tubing anchor of this invention may be said to comprise, generally, a tubular body In to be connected in the tubing string T, means II on the body for gripping the casing C and means l2 for operating the gripping means II.

The body l0 serves to carry or mount the various other parts of the tool and, in accordance with the invention, is a simple unit that may be readily interposed in the string of tubing T. The body I0 is an elongate tubular structure or member. In the particular case illustrated the body l0 comprises two sections [3 and I4, it being understood that the body I0 may be an integral element if desired or found practical. The upper and lower sections l3 and H are connected by a suitable threaded collar or coupling II. The longitudinal opening l8, extending through the tubular body sections i3 and I4, is preferably of the same diameter or fluid capacity as the opening in the tubing string T so that the body oflers no resistance or obstruction to the fluid flow and does not interfere with pump rod movement. In the case illustrated the opening It in the upper body section I! is enlarged at its upper end and is screw-threaded so that the body section l3 may be directly screwed onto the tubing T. The lower portion of the lower body section I4 is enlarged to have, what I will term. a chamber l1. An adaptor or sub l8 may be screwthreaded into the lowerend of this chamber i1 and may be screwed into a'boiiiSllng'N'Bf the tubing T to secure the lower end of the body In in the tubing string. The enlarged lower portion of the body section l4 just referred to has a flange or wall 20 of substantial vertical extent or thickness. This wall 20 occurs at the upper end of the chamber i1 and its function will be later described. The exterior of the enlarged lower portion of the body l may be provided with circumferentially spaced grooves or channels 9 to provide for the free passage of fluid. It will be observed that the body Ill just described is a simple inexpensive structure.

The means II is provided to grip the casing C to hold the tubing T against movement and more particularly is operable to maintain the tubing T under tension so that it cannot work up and down during operation of the well pump. The means II is in the nature of a wedge means or slip means and comprises two or more spaced wedge abutments or wedge faces 2| on the body II). In the preferred arrangement the means H is carried on the upper body section l3 and there is a. plurality of spaced wedge faces 2|. The body section it is provided with circumferentially spaced vertical or longitudinally extending ribs 22 whose outer surfaces are pitched or sloped to constitute the slip actuating faces 2|. As best illustrated in Fig. 3 of the drawing, the ribs 22 are spaced apart to leave ample fluid passages between them. It is preferred to provide the slip faces 2| with dove-tailed splines or ribs 23.

The casing gripping means ll further includes slips 24 which cooperate with the inclined faces 2!. The slips 24 are wedge parts having sloping inner surfaces which cooperate with the inclined faces 2| and having roughened or toothed outer sides curved to conform to the internal surface of the casing C. The pitched or inclined inner sides of the slips 24 are provided with dovetailed or undercut grooves 25 which slidably receive the tongues 23 to retain the slips in sliding cooperation with the faces 2|. The outer or active faces of the slips 24 preferably have teeth 26 for gripping with the internal surface of the casing C. In accordance with the invention the teeth 26 face upwardly and outwardly so that they are particularly effective in gripping the casing C to prevent upward movement of the tubing T. In this connection it is to be observed that the slips 24 have teeth of a different pattern or disposition than conventional slips. Conventional slips have teeth which are pitched in the opposite direction to their sloping inner sides. In the present invention the teeth 26 are pitched in the same general direction as the inclined inner sides of the slips 24 to hold the tubing T against upward movement.

The gripping means H preferably includes means for operatively connecting the several slips 24 for simultaneous operation. This means may include a tube or sleeve 21 shiftably or slid- I ceived by the pairs of spaced lugs 22 d 22 and pivot pins II and 22 carried by the lugs pass through openings in the links to pivotally connect the links with the slips and sleeve. It will be seen how the links 20 connect the several 814p! 24 with the sleeve 21 for simultaneous vertical movement therewith, while allowing free radial projection and retraction of the slips.

It is preferred to provide the tool with means for yieldingiy holding the slips 24 in the retracted positions so that the anchor may be run down through the casing on the tubing '1' without interfering with the casing, which means also aids in retracting the slips when the tubing '1 is to be withdrawn from the well. This means is preferably associated with the sleeve 21 to hold the sleeve in a position where the plurality of slips is retracted. The means for yieldingly holding the slips 24 retracted includes a spring 23 surrounding the body section l4 and housed within the sleeve 21. The internal diameter of the sleeve 21 is reduced adjacent the lower end of the sleeve providing an upwardly facing internal shoulder 24. The major portion of the sleeve 21 surrounds the body section I 4 with considerable clearance and engages over the collar II with suitable working clearance. The spring a is housed or received within the sleeve 21 and is arranged under compression between the shoulder 34 and the lower end of the coupling or collar ii. The spring 32 acting downwardly against the shoulder 24 yieldingly urges the sleeve 21 to the position where the slips 24 are retracted as shown in Fig. 1 of the drawing. It will be observed that the spring 22 is effectively housed and protected in the sleeve 21. The sleeve 21 engages about the body section l4 and collar II with suflicient clearance so that there is no dashpot action accompanying movement of the sleeve which might retard retraction or expansion of the slips 21, as the case may be.

The means [2 is a fluid pressure actuated means being operable by the hydrostatic pressure of the column of fluid within the tubing string '1". The means l2. when actuated, is operable to hold the tubing '1 against movement and. as will be later described, serves to hold the tubing string under tension, that is. it operates to prevent upward movement of the tensioned tubing. In accordance with the invention the means l2 includes one or more cylinders 22 and pistons 28 operable therein. In the construction illustrated one or more cylinder openings 2! are formed in the wall 20. With the particular construction disclosed there are three circumferentially spaced vertical cylinder openings 28 axially aligned with the ribs 22 and slips 24, it being understood that there may be any selected or required number of cylinder openings spaced and arranged as found most desirable. The cylinder openings 25 may be plain cylindrical openings of uniform diameter extending upwardly from the chamber ll to the upper end of the wall 20. A piston 36 operates in each cylinder opening 35. The pistons 36 may be solid cylindrical members of sufficient length to extend completely through the cylinder openings 35 and project from the end of the openings when in the unactuated positions. It is preferred to provide the pistons 36 with sealing rings 31 formed to efiectively seal with the Walls of the cylinder openings 35.

The upper ends of the pistons 36 are operatively associated or engaged with the sleeve 21. In the simple construction illustrated the upper ends of the pistons 36 have heads 38 presenting fiat faces which engage upwardly against the lower end of the sleeve 27. The sleeve 21 may have bosses or enlargements 39 adjacent its lower end to have complete engagement with the piston heads 38. The pistons 36 are formed and proportioned so that the sealing rings 37 never leave the cylinder openings 35 and the heads 38 are engageable with the wall to limit downward movement of the pistons. In accordancewvith the invention the pistons 36 are of sufficient length to either project into the chamber IT or to have their lower ends flush with the upper wall of the chamber ll when the pistons and slips M are in the fully actuated positions. With the pistons 36 engaged in the cylinder openings 35, as just described, the lower ends of the pistons are exposed to the hydrostatic pressure existing in the tubing T under normal pumping conditions and this pressure acts upwardly on the pistons to maintain them in the positions illustrated in Fig. 2 of the drawing where the slips 2 are fully actuated.

In the use or operation of the tubing anchor provided by this invention the anchor is interposed in the string of tubing T at the selected point when the tubing is assembled and run into the Well. The tubing T may be completely assembled and run into the well and its upper end may be bolted or otherwise secured to the usual tubing head at the ground surface. The well pump, not shown, is then run in on the sucker rod or pump operating rod. In the preferred mode of employing the invention the full weight of the pump and the string of pump rods is imposed on the tubing. The combined weight of the pump and the pump rod applied to the tubing '1 adjacent its lower end elongates or stretches the tubing, putting the tubing under tension. It will be assumed that the pumping assembly includes the usual foot valve which prevents the discharge of fluid from the lower end of the tubing. When the pump has been seated as above described the string of tubing T is filled with fluid. The weight of the long column of fluid thus provided in the tubing T subjects the tubing to further elongation and tensioning. It is to be observed that when the string of tubing T is subjected to the combined weight of the pump, the string of pump rod and the complete fluid column that it is subjected to a greater tensioning force than at any time during subsequent pumping operations. Filling of the tubing T with liquid as just described, is accompanied by automatic operation of the slips 24.

As the column of liquid builds up in the tubing T the pistons 36 are subjected to increasing hydrostatic pressure. When the tubing is completely filled the pistons 36 are subjected to the maximum hydrostatic pressure and will have been actuated upwardly to expand the slips 24 into tight gripping engagement with the casing C. It will be seen how the hydrostatic pressure acting upwardly against the pistons 36 moves the pistons, the sleeve 21 and the slips 24 upwardly. Upward movement of the slips 24 along the inclined faces 2| produces outward movement or expansion of the slips and causes the slips to tightly grip the internal surface of the casing C. Thus, the slips 24 are fully and efiectively operated into tight gripping engagement with the casing C when the string of tubing '1 is stretched and elongated to the maximum extent.

Following the actuation of the slips 24, as just described, the pump operating rod may be pulled upwardly to "space the pump and the usual or regular Dumping operations may be carried on. The raising of the pump rod removes a substantial part of the load or weight from the tubing T and the tubing tends to contract. However, the slips 25 being held in tight gripping engagement with the interior of the casing C prevent this contraction of the tubing T and maintain the tubing under tension. During the pumping operations the movement of the fluid column in the tubing T, the friction at the pump and the pump rod movement will tend to cause moving or "working of the tubing T. However, the slips 2t being in tight gripping engagement with the casing C and engaged between the casing and the ribs 22 dependably hold th tubing T against such movement or working. So long as the tubing T is maintained under tension through the gripping action of the slips 24 there can be little or no movement or working of the tubing. Accordingly, the tubing and the casing C are not subjected to the wear which usually accompanies the Working of the tubing.

When it becomes necessary or desirable to withdraw the tubing T from the well the column of liquid is drained from the tubing. This results in the automatic release of the slips 2B. When the liquid is drained from the tubing T the hydrostatic pressure is removed from the pistons 36 and the pistons are free to return to their unactuated positions. The weight of the sleeve 21, links 30 and slips 2% assisted by the spring 33 automatically retracts the slips 24. The dove-tailed splines 23 and grooves 25 assure positive retraction of the slips. Because the slip 24 are freed or released automatically upon draining of the tubing '1 the tubing may be pulled from the well immediately following the draining operation and no manipulation of the tubing is required to release the anchor. In this connection it is to be observed that the operation of the anchor is entirely automatic, that is, it is unnecessary to manipulate or operate the tubing T in order to actuate the anchor or to release the anchor.

The invention contemplates that the anchor may be employed either in the position illustrated in the drawing or in an inverted position. With the anchor employed in the position illustrated in the drawing there is absolutely no danger of the slips 24 interfering with the free withdrawal or pulling of the tubing T subsequent to draining of the tubing. With the anchor inverted from the position illustrated in the drawing it is necessary that the tool be constructed so that the slips 24 will be positively retracted from the casing C when the tubing T is drained. Such positive retraction of the slips 24 may be effected by the spring 33 or the equivalent.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims.

Having described my invention, I claim:

1. In combination. a well tubing, and an anchor for the tubing comprising a tubular body adapted to be interposed in a well tubing, slip means carried by the body for gripping the wall of the well to hold the body and tubing against upward movement, and means adapted to be actuated by the hydrostatic pressure of a column of fluid in the tubing for operating the slip means.

2. A tubing anchor for anchoring a string of well tubing in a well comprising a tubular body, connecting means for connecting the body in the string of well tubing, wedge slip means carried by the body for gripping the well casing to hold the tubing string against upward movement, and cylinder and piston means on the body actuated by the hydrostatic pressure of the column of fluid in the tubing for operating the slip means.

3. A tubing anchor for anchoring a string of well tubing in a well comprising a tubular body, connecting means for connecting the body in the string of well tubing, a part on the body having an inclined surface, a gripping slip operable into engagement with the well casing through movewent along said surface, and means operable by the hydrostatic pressure in the tubing for holding the sli in the position on said surface where it grips the well casing to hold the tubing against upward movement.

4. A tubing anchor for anchoring a string of well tubing in a well comprising a tubular body, means for connecting the body in the string of well tubing so that the opening of the tubular body forms a part of the passage through the tubing string, a part on the body having an inclined surface, a gripping slip operable into engagement with the well casing through movement along said surface. and means adapted to be operated by the hydrostatic pressure in the tubing for holding the slip in the position on said surface where it grips the well casing to hold the tubing against upward movement, said means comprising a cylinder in the body having communication with the interior thereof, and a piston in the cylinder operatively associated with the slip.

5. A tubing anchor for anchoring a string of well tubing in a well comprising a tubular body, means for connecting the body in the string of well tubing, the body having a chamber in communication with the interior of the tubing and a cylinder opening in communication with the chamber, a part on the body having an inclined surface, a slip operable outwardly into gripping engagement with the casing when moved along said surface, and a piston operable in said opening by the hydrostatic pressure in the tubing for moving the slip along said surface to actuate .a part on the body having an inclined surface,

a gripping slip operable into engagement with the well casing through movement along said surface, cylinder and piston means on the body operable by the hydrostatic pressure in the tubing passage for moving said slip along said surface, and spring means for retracting said slip when the hydrostatic pressure is reduced.

7. A device for anchoring a string of well tubing in a well casing comprisinga tubular body, means for connecting the body in the tubing string to form a part thereof, the body having inclined surfaces, slips operable along said surfaces to grip the casing, a sleeve shiftable on the body and operatively connected with the slips, the body having a plurality of cylinder openings in communication with the interior of the tubing, and pistons in said openings operable by the hydrostatic pressure in the tubing to move the sleeve and thus actuate the slips to grip the casing and hold the tubing against upward movement.

8. A device for anchoring a well tubing in a well casing comprising a tubular body adapted to be interposed in the tubing, the body having inclined surfaces, slips operable along said surfaces to p the casing, a sleeve shiftable on the body and operatively connected with the slips, the body having one or more cylinder openings in communication with the interior of the tubing, and pistons in said openings operable by the hydrostatic pressure in the tubing to move the sleeve and thus actuate the slips to grip the casing, the weight of the slips and sleeve tending to move the slips to retracted positions when the hydrostatic pressure drops.

9. A device for anchoring a well tubing in a well casing comprising a tubular body adapted to be interposed in the tubing, the body having inclinedv surfaces, slips operable. along said surfaces to grip the casing, a sleeve shiftable on the body and operatively connected with the slips, the body having one or more cylinder openings in communication with the interior of the tubing, pistons in said openings operable by the hydrostatic pressure in the tubing to move the sleeve and thus actuate the slips to grip the casing, and spring means for retracting the slips when said hydrostatic pressure drops.

10. A device for anchoring a well tubing in a well casing comprising a tubular body adapted to be interposed in the tubing, the body having inclined surfaces, slips operable along said surfaces to grip the casing, a sleeve shiftable on the body and operatively connected with the slips, the body having one or more axial cylinder openings in communication with the interior of the tubing, and pistons in said opening operable by the hydrostatic pressure in the tubing to push said sleeve axially of the body and thus move the slips along said surfaces.

11. A device for anchoring a well tubing in a casing comprising a tubular body to be interposed in the tubing, the body having a chamber communicating with the interior of the tubin and axial cylinder openings leading from the chamber, spaced sloping parts on the exterior of the body, slips operable along said parts to be moved into gripping engagement with the casing, a sleeve shiftable on the body, operative connections between the sleeve and slips, and pistons operable in said openings to move the sleeve and thus operate the slips along said parts.

12. A device for anchoring a well tubing in a casing comprising a tubular body to be interposed in the tubing, the body having a chamber communicating with the interior of the tubing and axial cylinder openings leading from the chamber, spaced sloping parts on the exterior oi the body, slips operable along said parts to be moved into gripping engagement with the casing, a sleeve shittable on the body, operative connections between the sleeve and slips, a spring in said sleeve reacting between the body and sleeve to yieldingly hold the sleeve in a position where the slips are free of the casing, and pistons operable in said openings to move the sleeve and thus operate the slips along said parts.

13. A device for anchoring a well tubing in a casing comprising a tubular body to be interposed in the tubing, the body having a chamber communicating with the interior of the tubing and axial cylinder opening leading from the chamber, spaced sloping parts on the exterior of the body, slips operable along said parts to be moved into gripping engagement with the casing, a sleeve shiitable on the body, operative connections between the sleeve and slips, and pistons operable in said openings to move the sleeve and thus operate the slip along said parts, the pistons projecting into said chamber at all time to prevent sanding up of the cylinder openings.

14. A device for anchoring a well tubing in a casing comprising a tubular body to be interposed in the tubing, the body having a chamber communicating with the interior of the tubing and axial cylinder openings leading from the chamber, spaced downwardly and inwardly sloping parts on the exterior of the body, slips operable along aid parts to be moved into gripping engagement with the casing, upwardly and outwardly facing teeth on the slips for gripping the casing, a sleeve shiftable on the body, operative connections between the sleeve and slips, and pistons operable in said openings to move the sleeve and thus operate the slips along said parts.

. JOHN 5. PAGE.