US2942669A - Inflating pump for oil well packers - Google Patents

Description

June 28; 1960 W. D. MOUNCE ETA]- INFLATING PUMP FOR OIL WELL PACKERS Filed Nov. 29, 1957 INIENTORS. WHITMAN n. MOUNCE, ADELBERT BARRY,

ATTORNEY United States Patent INFLATING PUMP FOR OIL WELL PACKERS Whitman D. Mounce and Adelbert Barry, Houston, Tex., assignors, by mesne assignments, to Jersey Production Research Company, Tulsa, Okla, a corporation of Delaware Filed Nov. 29, 1957, 'Ser. No. 699,649

1 'Claim. (Cl. 166-187) This invention concerns a pump for expanding inflatable packers in a well bore. More particularly, the invention relates to a pump for inflating packers used in conducting drill stem tests or temporary well completions.

As drilling of a borehole proceeds, there are indications (such as loss of returns, etc.) which suggest the desirability of testing certain formations for oil. So-called drill stem tests are made for that purpose. Appropriate testing equipment is attached to a drill stem and lowered to the formation to be tested. A packer in the equipment is inflated to effect a seal against the wall of the borehole. Such a seal eliminates communication of the drilling fluid from the annulus above the packer surrounding the drill stem to the isolated section below. Valves in the testing apparatus are then opened by appropriate mechanisms to permit formation fluid from the isolated section to enter the empty drill stem above the packer. After a suflicient time, the valve is closed, the packer deflated, the stem removed, and the formation fluid recovered for examination and testing on the surface.

When employing an inflatable type packer, it is desirable to know the safe inflate capacity of the packer. Because of unknown washouts, etc., the diameter of the borehole may be larger than the diameter to which the packer is capable of expanding. In such instances, the packer may be damaged or may burst from over-inflation. In present systems in which are used mud pumps employing well drilling muds as the packer expanding fluids, over inflation, with resulting damage to the packer, may occur.

Also, the caliper of the well bore at the packer seal location is desired. For example, in a drill stem test the diameter of the borehole at the packer location gives an indication of l) the type formation being tested and (2) how good a seal the packer is capable of effecting at that location.

Therefore, an object of this invention is to provide a pump for well packers wherein the pump is limited to a safe packer inflate capacity. Additionally, as object of the present invention is to provide a pump for well packers wherein the diameter of the well bore at the packer set location may be measured quickly and easily.

Briefly, the invention comprises a pump for inflating a packer comprising a cylinder connected to said packer, said packer including first and second passageways and said cylinder fluidly communicating with said first passageway, a movable hollow plunger provided with a piston arranged in said cylinder and adapted to connect to a tubing string exterior of said cylinder, guide means arranged on said cylinder adapted to guide said plunger, and a pipe arranged in said cylinder and extending through said piston adapted to fluidly communicate the interior of said plunger and said second passageway.

The above objects of the invention and other objects will be apparent from a description of the invention taken in conjunction with the drawings wherein:

Fig. 1 is an elevational view of the apparatus of the invention connected to a packer arranged in a borehole and showing the equipment in packer inflated position;

Fig. 2 is a view similar to Fig. 1 showing the equipment in packer deflated position;

Fig. 3 is a elevational view, partly in section, of the pump of the present invention; and

Fig. 4 is an enlarged view of the valving arrangement of Fig. 1.

In Figs. 1 and 2 is shown a borehole 10 in which is arranged a perforated tail pipe 11 positioned on the bottom of borehole 10 and connected to a packer section 12 provided with an inflatable packer element 9 and which, in turn, is connected to a pump section 13. Atubing string 14 is connected to the upper end of pump section '13.

Pump section 13 (Fig. 3) includes a cylinder 20 to which is connected at its lower end a cylinder sub or closure member 21. Closure member 21 is formed to provide fluid passageways 22, 23, and 24. A mandrel 25 which forms part of a packer assembly, generally designated 26, is connected to closure member 21. Mandrel 25 is formed to provide a fluid passageway 28 which fluidly communicates passageway 22 and the interior of packer 9 (not shown) and a fluid passageway 27 which extends through packer section 12. Suitable sealing means 29 and 30 are arranged on mandrel 25 and closure member 21, respectively, for sealing off the annulus between mandrel 25 and closure member 21 above and below the connection between passageway 22 and passageway 28.

A guide head 31 is connectedrto the upper end of cylinder 20. A piston 32 to which is connected a hollow plunger 33 is slidably arranged in cylinder 20. Plunger 33 extends through guide head 31 and connects to tubing string 14. A stop ring 34 is secured to plunger 33 by means of screw 35. The interior surface of plunger 33 is circular and the exterior surface thereof is square, as shown in Figs. 1 and 2 more clearly. The interior of guide head 31 is also formed square thereby providing a keyway in guide head 31, which prevents rotation of plunger 33 with relation to cylinder 20. This structure is desirable for operation of certain standard test tools which require rotary motion for operation. When using such a tool, torque is applied to the drill stem at the well surface in order to close valves in the tool after entry of formation fluids into the drill stem above. An anchor shoe at the very end of the drill stern holds the lower end of the stem anchored as the torque is applied. If the pump described herein is used above the packer, the keyway arrangement mentioned above is necessary to prevent rotation of plunger 33 during application of the torque.

A pipe or stringer 36 fluidly communicating with passageway 27 is secured to closure member 21 and extends through piston 32 into the interior of plunger 33. Packer inflating fluid 37 is contained in cylinder 20. Passageway 23, provided at one end with a plug 8, is employed for filling cylinder 20 with fluid 37. Sealing means 38 is arranged in closure member 21 adapted to seal off the annulus between pipe 36 and closure member 21. Also, sealing means 39 are arranged on piston 32 adapted to seal off the annulus between piston 32 and the interior wall of cylinder 20 and sealing means 40 is arranged on piston 32 adapted to seal off the annulus between piston 32 and the exterior wall of pipe 36.

A valve assembly 41, shown more clearly in Fig. 4, is arranged in passageway 22. Passageway 24 fluidly communicates with two oppositely disposed check valves 42 and 43, which, in turn, fluidly communicate with fluid passageway 22 via conduits or branch passageways 44 and 45, respectively. A plug 46 is arranged in closure member 21 for facilitating positioning and removal of valve elements 42 and 43. Sealing means 47 are provided for sealing off the various flow passages. Check valves 42 and 43 include spring members 48 and 49, respectively, and ball members 50 and 51, respectively. Spring member' 43 is of suflicient strength to prevent movement 'off'fluid""from cylinder 37 through fluid passageway 24 to fluid passageways 45 and 22 when the piston is in the upper position as shown in Figs. 2 and3. The various sealingmeans 29,30, 38, 39, 40and 47 maybe suitably O-ring seals. i

' Operation The apparatus is lowered .in borehol'e 10 with packer 9 in deflated position until tail pipe 11 engages the bottom of borehole 10. Then the'usual setting down of weight .upon drill stringn14 against the bottom of the borehole causes plunger 33 to move-downwardly within cylinder 20. 1 Packer inflating fluid'37 is thereby forced by piston '32 downwardly through-fluid passageway '24, valve 43, passageway 45,, passageway 22, andpassageway-28 to the :interior of' packer 9 and the-packer is expandedoutwafily against'lthe walls of :the borehole, as shown in Fig. 1. rTheinflating pressure inside the packeris controlled di-. :rectly in proportionto the weight put on the drill string.

When the 'zpacker has expanded into sealing I engage- ;ment with the-borehole wall the formation fluids move :through the perforations in tail pipe 11 through passage- "way 27, through the interior of pipe '36 and through the interior ofplunger '33 into drill pipe 14 and thence to the'surfaceof the earth.

ILifting-of weight from the drill :string permits the packer to deflate as plunger 33, is withdrawn upwardly .torecover the inflate fluid back into cylinder 20. Thus, when weightis. released from drill string 14, piston 32 moves upwardly until stop member 34 engages the lower *side'of'guide head 31. Fluid withinpacker 9 moves upwardly through passageway 28, passageway 22, passageway 44, valve member 42,- and passageway '24 into the interior of cylinder 20. V

' As readily ,seen'the present invention has two distinct advantages over present packerpumps. First, the stroke :ofthe inflatingpumpand therefore the available fluid is 'limited to a safe inflate capacity of the packers. Second, the stroke of the inflating pump is directlyproportional .to the .inflate diameter of the packer.- Therefore,.by measuring thedownward travelof 'drill string 14 at the surface of the earth after tail pipe 11 has touched the bottom of the borehole, and making a correction for known stretch in the drill pipe 14, the stroke of the inflating pump in the hole is determined. Knowing the cylinder and provided with a first passageway; a packer assembly connected to said closure member and'provided with an inflatable element and second and third passageways, said third passageway fluidly communicating said first passageway and the interior of said inflatable element, said second passageway extending through said packer assembly; a movable hollow plunger adapted to be connected to aitubing string exterior 10f saidcylinder at one end and provided with apiston atthe other end thereof movable 'from'anupper, to a lower'position and "vice versawithin said cylinder; aguide member arranged including two branch passageways, said valve means bek ing adapted to retain packer inflate fluid in said cylinder when said cylinder is in said upper position, said valve means fluidly communicating said cylinder and the interior of said inflatable element via said first and third passageways and one of said branch passageways'and being adapted to close'off fluid communication thru said other branch'passageway when'said piston-moves downwardlyfrom said upper to said, lower position, said valve means being adapted toIpermit release of packer inflate fluid, from the interior of said inflatable element to said cylinder via said first and third passageways and the other of said branchpassageways and being adapted to close off fluid communication thru said one branch passageway when said piston movesupwardly from said lower to said upper position; the predetermined amount of fluid adapted to be contained in said cylinder providingta'safe inflate capacity for said infiatablej element and the length of travel of said plunger being measurably related to the inflate diameter of said inflatabletelement.

References Cited in the file of this patent UNITED STATES PATENTS -Lynes Jan. 22, 1957

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