US2885968A

US2885968A - Special bottom hole pump anchor

Info

Publication number: US2885968A
Application number: US439370A
Authority: US
Inventors: Harold H Wagner
Original assignee: Pan American Petroleum Corp
Current assignee: Pan American Petroleum Corp
Priority date: 1954-06-25
Filing date: 1954-06-25
Publication date: 1959-05-12
Anticipated expiration: 1976-05-12

Description

May 12, 1959 H. H. WAGNER SPECIAL BOTTOM HOLE PUMP ANCHOR Filed June 25, 1954 fr/9 2 INVENToR.

Harota H. Wagner ATTORNEY O United States Patent O n SPECIAL BOTTOM HOLE PUMP ANCHOR Application llune 25, 1954, Serial No. 439,370 7 Claims. (Cl. 10S-219) This invention relates to an oil well pumping apparatus. More specifically, this invention relates to an insert pump which can be operated at any desired depth within a tubing by employing a special insert pump anchor.

In the completion of deep oil wells which operate under high pressure and particularly in those wells which flow, it is often desirable to insert the tubing in the well while the well is under pressure control as by being filled with a weighted drilling fluid and then to complete the well by removing the weighted drilling iluid and perforating the casing. The casing is perforated using a small diameter gun perforator which is lowered into the well through the tubing. This well completion practice is often referred to as permanent type well completion. In such completion operations and in many other cases as, for example, where it is not known at what depth a pump will eventually be placed in a well, it is `generally considered desirable to leave the tubing completely open, i.e., to provide no restrictions in the tubing so that well completion tools such as gun perforators, bailers, bottom hole pressure instruments, para'in Scrapers, tubing calipers and the like of the largest possible diameter can be lowered through the tubing. Thus, whereas an insert pump anchor or landing nipple is often placed in a tubing string when a well is completed, in this permanent type Well completion practice any constriction such as a landing nipple is undesirable and should be left out if possible. Additionally, after a well is placed on the pump, it is often desirable due to a change in the working fluid level of the well and the like to be able to change the elevation of a pump in a well without moving the` tubing. n

Various means have been proposed for anchoring an insert type pump in a well flow conduit. Generally a pump is anchored by placing a shoe, abottom pump collar, a landing nipple, or the like7 at a xed position in the tubing as a permanent part of the tubing string.

Temporary or movable anchors which will permit the pump to be operated at diterent depths in a xed conduit are considered more desirable. Temporary anchors previously proposed consist generally of slips and a packer connected to and supporting the insert pump and sealing the ow channels around the pump in the tubing. Inasmuch as the pump and `associated apparatus in` an insert pump installation are relatively light weight, it has been found that the anchor means often becomesunseated. Furthermore, in the movable anchors previously proposed, J-slot means must be provided for holding the slip means out of operative position so that the anchor can be placed in the conduit. Also, since J-slot means require rotation of the pump and packer mechanism relative tothe slips to seat the pump and since this relative rotation between the pump and the slips is` often difficultparticularly in small `size pumps, pumps cannot be set even after they are `lowered into position.. n

It is, therefore, a principal object of this invention to provide an insert pump and anchor in which the stop or support part of the anchor means as a separate unit coacts with the pump but is set in a conduit as a step separate and distinct from the setting of the pump and packer or hold-down means. It is a more specic object ot this invention to provide a deep well insert pumpl in which the pump and hold-down are connected as a unit and are located in the well by a stop that is set in the Well tubing at a desired elevation before the pump and hold-down unit is lowered into the well and that is not directly connected or iixed to the pump and hold-down unit. It is still a more specific object of this invention to provide a movable insert pump anchorl with means for draining the fluid head on the pump when the pump is to`be pulled so that the tubing is not swabbed when the pump is` pulled. These and other objects of this invention will become apparent from the following description. In this description, reference will be made to the accompanying drawings in which:

Figure lis an elevational view partially in cross section of a removable stop for anchoring a pump at a desired elevation in a well;

Figure 2 is an elevational view partially in cross section of an insert pump hold down including packer elel `valve means to drain the flow conduit above the pump so that the pump can be Withdrawn from the ilow conduit vwithout withdrawing the pump stop :and without lifting or swabbing all of the well fluids in the ow conduit. n i

Referring now to the drawings and more specically n to Figure l which shows a removable stop A, this removable stop is first lowered into the well and positioned at the desired elevation within the tubing Z9 by means of wire line tools (not shown) including jars and a disconnectable setting tool as is well known in the art. The

removable stop includes an elongated tubular mandrel 30 having an axial bore 31. The lower portion 32 of the mandrel is substantially cylindrical and an external annular flange 33 is provided at the upper end of this` cylindrical section. Immediately above the ange 33, `the mandrel is ared outwardly and upwardly to form a slip expanding section` 34, and an` upwardly facing annular shoulder 35 is formed at the upper end of the flared section.-` A retrieving connectioniorlshing head including an undercut `annular ange 36 at the upper end of the mandrel is spaced above the shoulder 35 and is adapted to `be engaged by a suitable retrieving tool (not shown) whereby the stop maybe placed in and removed from the well tubing.` j n j Gripping elements or slips 37 having gripping teeth on their louter surfaces are slidable on the flared slip expanding` section 34 of the mandrel. Slip supports 38 extend downwardly through slots (not shown) in the ilange 33. The lower ends of the slip supports are loosely connected-to a` slip carrier or sleeve 39 by means of slots 40 which` engage the projections 41 provided in the upper `portion of the zslip carrier. strained against outward displacement from between the projections on the slip carrier by a band 42 which surrounds said carrier and is secured in an annular groove formed `in its outer surface. A similar band 43 prevents outward displacement of the slip supports from the slots inthe annular ange 33". The slip carrier is slidableon the `lower cylindrical portion 32 of the mandrel and up-` The slips are `reward movement of the slips on the mandrel is limited by the engagement of the carrier with the flange 33.

As will readily be seen, the weight of the slips will urge them to their lowermost positionr on the mandrel where they engage the flange 33.A However, downward movement of the mandrel relative to the slips will'move the flared slip expanding section 34 downwardly between the slips and force them outwardly into gripping engagement with the inner wall of the tubing. Such relative movement may be obtained by suddenly lowering the mandrel at a rate greater than the acceleration of gravity. Also, the slips may be raised rapidly ywith'the mandrel, and if the mandrel is then reversed sharply, the slips will remain substantially stationary, due to their inertia, and the flared portion of the mandrel will move between them to yimmediately expand them into gripping engagement with the tubing.

After this removable stop has been placed in the tubingV at the desired elevation and the running tool has been removed,'the pump and hold down are `made up as a unit at the surface and lowered into the tubing on the rod string as it `is made up. The hold down as shown in Figure 2 consists of a lower shoe 44 having a bottom bore 45 which may pass over the annular ilange 36 and seat on annular shoulder 35 on the removable stop A as shown inFigure l. Alternatively, and in the preferred embodiment, the shoe 44 may be seated on the annular flange 36 to avoid any possibility of the pump and anchor becoming .locked together by sand or the like settling in the shoe. This shoe is connected to the lower end of a mandrel 46. This mandrel has a number of perforations 47 at about its mid point. One or more packers 48.preferably' of the swab type and sometimes referred toas packer rubbers are placed on the upper end of the mandrel above the perforations 47. These packer rubbers are resilient and preferably fabric-reinforced rubber of the type available cornmercially as swab cups. The packers are supported 'at the lower end on the mandrel by a packer head49which' is connected by one or more shear pins 51 to mandrel' 46. In some cases, it may be desirable to provide a seal, typically an O-ring seal 52, between the packer head and the mandrel to prevent high pressure well iluids from leaking back into the well around the mandrel. Spacer sleeves 53 may be provided in some cases as desired to hold the packers in position, particularlyas the pump and hold down are being lowered into the tubing. A pump adapter 54 connected to the upper end of the mandrel holds the sisting vof cups 62 on pump piston 63,"ball 64', and seat logging devices, and the like having an'external diameter substantially equivalent to the inside diameter `of the tub# ing may then be lowered through the tubing tothe bottom of the kwell during completion or 'subsequent 'production Eventually when `it isf'desired'toplacefthe' of'the well. well on'artflcial lift, removable'stop `Aris loweredy into the tubing to the desired location,preferably below the working liquid level, on a setting tool and there by 'jar-ring the removable stop, the .slips` 37 are expanded by the in- Cline expanding section 34 so that the outside diameter of the slips isas great as the inside Vdiameter offthetubing. The removable stop is thus fixed at the desired elevation in the tubing. The pump and hold down are then lowered panded .against the Itubing, preventing l the welli iluids from l flowing around-'the pump back'intof the well' and intothe pump suction. The shear pins 5l have sutlicient'crosssectional areatosupport the'weight ofthe expected iluid head total.' That is, the shear pins 51 are designed for each pump setting so that they vwill support the total load including the weight of the Well lluids above the pump and the back pressure maintained on the well at the tubing outlet at the surface. Typically, the shear pins are designed'to withstand a minor additional load before shearingso as to prevent the pins from being shearedaccidentally.

When it is desiredto pull the pump,- as for example to repair a broken rod or to repair the pump, the welllluidsl in the tubing above the packers are drained back into the well through the perforations- 47. These perforations are uncovered to provide a passage for the iluid between the outside'of the pump and the inside of the mandrel by shearing pins 51 and moving the packers down to the lower end of mandrel 46. The pins are sheared vby rst raising the'rods 67 untilupper` valve housing strikes stop 68 on the upper end of pump barrel 58. The pump and hold`down are thenraised a short distance, typically octween about 2 and about 10 feet or more, and dropped. Movement of the top of the rod string is stopped suddenly causing rapid deceleration of the mandrel andattached pump, or the shoe 44 may be allowed to strike the'removable stop. The inertia of the well lluids then exerts a downward force on the packers which is substantially the packers will be washed out of the packer with the well fluids.

After the well iluids have been permitted to drain back into the Well, the4 pump and attached hold down can be pulled out of the well for repair or the like. Obviously,

with the pump and hold down combination removed from f the well, the removable stop A can be removed from the well or movedto a new location if desired so that wheny the pumpand hold down combination is reinserted, the pump will operateat a different elevation. The particular advantage of this invention, however, as will be Aapparent from the above, is first, that the pump" can be removedl and reinstalled at exactly the same positionin the tubing `as many times as desired and secondfthat since the pumpcand hold down unitis not connected di'- rectly to the removable stop, there is very little, if any, tendency for the stopto become unseated in the tubing as the Well is pumped. That is, there is no force tending to lift the removable stop when the rods and traveling valve are lifted. Consequently, the pump does not tend to vbecome unseated or to walk upthe tubing 'as the wellis pumped. Furthermore, and `this is particularly desirable, the pump can be removed without swabbing the tubing or destroying the packers. Thus it can be seen that this invention providesa substantial-'improvement over insert pump anchors previously used and thatthe invention yis lsusceptible' of a wide variety of modifications which'willbe apparent from the above description which` annabee is given by way of example. The invention should, therefore, be construed to be limited only by the scope of the appended claims.

I claim:

1. A well pump for pumping at any desired elevation in a Well conduit comprising a removable stop set in said conduit at said desired elevation, a pump and pump hold down unit supported by but capable of being separated from said removable stop within said conduit, said hold down unit including a tubular mandrel connected to the intake of said pump, and packer means connected to said mandrel to seal the space between said mandrel and well conduit, means forming at least one perforation extending from the interior to the exterior of said mandrel at a midpoint in said mandrel, and frangible means connecting said packer means to said mandrel above said perforation.

2. A well pump according to claim 1 in which said packer means consists of at least one swab cup having the open end up.

3. A well pump according to claim 2 in which said frangible means is a shear pin having an area sufficient to support only slightly more load than the weight of the full liquid column in said well conduit above said packer means plus the load due to operating well head pressure.

4. A Well pump comprising a removable stop positioned `in a well conduit, a tubular mandrel capable of being separated from but supported on said removable stop within said conduit, means forming a perforation extending from the interior to the exterior of said mandrel at a midpoint in said mandrel, packer means on said mandrel adapted to seal the space between said mandrel and said conduit and prevent well fluids from passing downward between said mandrel and said conduit, frangible means connecting said packer means to said mandrel above said perforation, and pump means including a pump barrel connected to the upper end of said mandrel to `lift wel-l fluids through said conduit, whereby said pump means may be positioned in said well conduit and supported on said removable stop at any elevation desired and said pump means may be removed from said conduit without removing said removable stop.

5. A well pump according to claim 4 in which said packer means consists of at least one swab cup having the open end up.

6. An apparatus for use with a separate removable stop to anchor in a well conduit a pump having a barrel, a traveling valve in said barrel and a standing valve at the lower end of said barrel, said apparatus comprising a tubular mandrel adapted to be connected at the upper end to one end of said barrel, a perforation extending from the interior to the exterior of said mandrel at a mid-point in said mandrel, a packer on said mandrel mounted to slide axially on said mandrel and adapted to seal the space between said mandrel and said conduit, and frangible means to support said paclcer on said mandrel above said perforation, the space between said perforation and the bottom of said mandrel being longer than said packer, whereby said packer when initially in a pumping position is supported above said perforation to prevent well fluids from bypassing said pump and, when said pump is to be pulled, said packer may be moved down on said mandrel to uncover said perforation so that well fluids may bypass said pump.

7. A pump anchor for holding a well pump down on a stop which is separately removable from a well conduit, said pump including a pump barrel, a traveling valve in said barrel, a standing valve attached -to said barrel, and means to reciprocate said traveling valve in said barrel, said pump anchor comprising a tubular mandrel adapted to be connected at the upper end to said barrel, a packer on said mandrel mounted to slide axially on said mandrel, a perforation extending from the interior to the exterior of said mandrel, said perforation being spaced from the lower end of said mandrel a distance as great as the axial length of said packer, and frangible means connecting said packer to said mandrel above said perforation, whereby said packer initially prevents well iluids from bypassing said pump through said perforation and finally when said frangible means is broken said packer uncovers said perforation and permits well fluids to bypass said pump through said perforation so that said pump can be pulled dry without pulling said stop.

References Cited in the le of this patent UNITED STATES PATENTS 456,128 Darling July 14, 1891 1,151,765 Drader et al Aug. 31, 1915 1,332,672 Ligon Mar. 2, 1920 2,027,783 Martin Jan. 14, 1936 2,125,231 Hurst a-.- July 26, 1938 2,244,051 Collins .Tune 3, 1941 2,253,776 Gaunt Aug. 26, 1941 2,274,093 Ragland Feb. 24, 1942 2,274,740 Reynolds Mar. 3, 1942 2,327,503 Coberly Apr. 24, 1943 2,393,404 Otis Ian. 22, 1946 2,604,945 Page July 29, 1952