US2842211A - Oil well tool - Google Patents

Description

July 8, 1958 E. w. MCGAFFEY OIL. WELL TooL Filed Nov /l 1 g m I F m RM." {Vfwu P l Vwr. In. h f mM o w S 4 V .t 8 N e 3 l 8 2 I 2 l In M i oo 2 rv m 2 .WJ x

July 8, 1958 OIL WELL TOOL 2 Sheets-Shee'. 2

Filed NOV. 15, 1952 v. E F .m n.6 ww mw o l( VR l. 2 o mm w i 3 3 5 D lrmd5 a 3 Inn.' 4| ...3 a. a B. 3 a 4 lima? 2 2 i 9J 3 w 4 i 2 3 w 5 o 3 l @u O f o n. M

United States Patent() 6 Claims. (Cl. 166-101) This invention relates to oil well tools and more particularly to an oil well cleaning device for washing perforations in oil well casings.

In the production of oil wells, the bore hole is generally lined with casing pipe extending downwardly in the well to oil sands at which point the pipe is perforated. The oil flows into the casingpipe through these perforations, whence it is lifted to the surface. During this producing operation the perforations oftentimes become. clogged with mud, sand, tar, or debrisof one sort or another, which tend to retard the flow of oil intorthe casing pipe.

In the past, various types of well cleaning devices have beenfproposed for removing such debris, one such form of device comprising spaced packing means adapted' toy be lowered into the well adjacent the perforations to` be cleaned, and dening with the perforated casing pipe a confined space into which uid mayv be pumped under pressure by suitable cylinder; and piston arrangements in the tool, and forced through the perforations. Another cleaning device of the above typeV uses spaced packing means, whose positions with respect to one another may be varied, whereby the conned space between the packers is varied, and thus the pressure changed to-force iiuid into or out of the adjacent perforations.

The present invention contemplates an improved oil v well cleaning device incorporating the above principles and has as its primary object to provide greatly increasedr pressures in a confined packed-off space for forcing lluids through the perforations toY be cleaned.

Another object is to provide such a device in which suction pressure greater than` has heretofore been attainable may be applied to perforations.

Still another object ofthe invention is to provide a device in which a chemically treated fluid may be introduced into a confined space opposite the perforations, and forced through said perforationsunder great pressure.

These and further objects and advantages of the invention are attained by means of a cleaning toolprovided with spaced packing means, one packing means being movable with respect tothe other. The tool also includes ing uids through the perforations. In thisinstance thev piston and cylinder arrangement provide an initial suction and then one packing means is moved away from theV other to increase the volumeof conlinedzfspace, therebyV causing an additional suction.

-A better understanding o they inventionand' itsy varif. l CC ous features and advantages `will be had by referringl to the following detailed description in conjunction with the accompanying drawings, in which:

Figure 1 illustrates partly in section a preferred form of the well cleaning device in one extreme` position;

Figure 2 illustrates the device of Fig. 1 in a second extreme position; v

Figure 3 illustrates a modification ofthe device ofrFig. l inone position; and Figure 4`shows the device of Fig. 3 in a second position. Referring to the drawing, there is shown in- Figures l and 2 a casing pipe 10 including a plurality of perforations or openings 11 through which oil may be recovered fronrsurrounding oil. sands' in the earthforrnations.y The cleaning device of thepresent invention is supported on the end of the usuali drill pipe 12 or any other type of suitable tubingv providing a fluid passage. This connec-4 tion is effected by means of a coupling 13havinga1owei annular shoulder 13. and including a one-way` check valve 14. Threadedly secured to the coupling` 13 is an elongated hollow piston rod. 15y terminating in aV piston head 16, the hollow tubular piston rod 15 being reciprocably'operable in a main cylinder -1-7; As shown, the upper end Wall 18 of the cylinder17 includes a clutch mechanism 18 adapted'to engage a-r cooperating clutch mechanism in the piston head 16 when the piston rodv and piston head are at the upper end of their stroke; A breather port 17 is provided in the upper end of cylinder 17.

The cylinder 17 ispreferably divided into two chamf bers 21l and' 22 by acoupling 19 i`ncluding a second check valve 20, the two sections .defining these chambers being conveniently threaded to the coupling 19.

Within the-lower chamber 22 of the cylinderV 17 there is provided a plunger 23 mounted on' atubular member 24 reciprocably operable in the lower chamber 22 through bushing 2 5. The tubular memberr 24n extends beyond the llower endv of the cylinder 17 through a support 26 mounting stationary packing means 2,7. Plunger 23"and bushing 25 include respectively clutch members23 yand 25 adapted to engage each otherto prevent relativero.- tation of the tubular member 24 and cylinder 17 when the plunger and tubular member are in their lowermo'st posi-` tionf Mounted exteriorly of thelower end of thev cylinder 17, on bushing 25, is a movable packing means 28. This packing means* 28 is rigidly secured to the, cylinder andbushing and thus will move with the cylinder as will be described in connection with the operation of the tool. TheA support 26 may take the' formv of a cylindricalsleeve surrounding and threadedly locked tothe tubular, member24. This support includes at its lower end conically inwardly sloping surfaces 26 deiining slip expandf' ingA means. A lowery sleeve member 29 mounting, belly surface 26 of the slip expander.,` A bayonet slot33 isv provided in the sleeve 294 and a cooperating pin 34 on the; l

tubular member 24.

'Ilhe'extrerne lower end of the tube 24 includesports'risr having'fluid communication' up through thetube V24'y with.

a port 36 in the, upper end of tube 24am-da .port 36v in tlie'lower end of cylinder 17. This communication serves` tobypas's well fluids-about the packing,meanswhenutheinstrument is moved in the bore hole. The upperporimand 2s. j p Y Y Y ,f

lIn operation' of the device shown in' Figures l and 2,`

lowered into the well casing by the drill pipe 12 to a position opposite perforations 11 to be cleaned. When the device is being lowered, the piston 16 and clutch 16 arelin 'engagement with the end wall 18 andv clutch 18", and the plunger 23 and clutch 23 are in engagement 'with the bushing 25 andrnating clutch 25 as shown. fl his iirst`engagement of clutch 16' and 18results from the weight of the cylinder 17,V which weight is supported by the piston 16. YThe second engagement ofpclutch 23 and 25` results from the weight of the tube 24, support 2,6, and the'slip apparatus, which weight is supported by the top of bushing 25 and lower portion of cylinder 17. xAs' soon as the tool is properly positioned in the bore hole, the drill' pipe 12 is turned which rotates the hollow piston rod 15, cylinder 17, plunger 23, and hollow tubular member 24 thereby rotating the pin 34 to move it along the horizontal portion of the bayonet slot 33. The sleeve 29, links 31,:and slips 32 will not rotate `because of the friction of the belly springs 30 against the bore hole casing.V When ,the pin 34 has reached the end of the horizontal portion of the bayonet slot 33 the drill tubing 12 is then lowered and the pin enters the vertical leg of the 'bayonet slot. fFurther lowering of the drill pipe 12 causes the pin 34 and tube 24 to travel downwardly, and this action pushes the slips 32 along the sloping walls 26 of ,thel slip expander, the slip including teeth which engage the casing and throughly lock the lower portion of the tool in place. This action in turn insures that the packing means 2.7,is stationarily secured with respect to the casing in the position as shown in Figure l. e IFluidis n ow pumped down through the drill pipe 12, hollow'piston rod 15 and into the upper chamber 21 of the cylinder 17. This fluid will also pass through the check valve 20 down into the lower` chamber 22 and through passage 37 in the tubular member 24 out into the coniined volume V.

, Reciprocation of the drill pipe 12 will initially operate the piston 16 to force uid in chamber 21 through the check valve 20 into chamber 22 and down the passage 37 into the confined volume V as indicated bythe arrows, increasing the pressure `between the spaced pacldng means 27 and 28. As soon as the piston 16 reaches its lowermost position the shoulder 13 of the coupling 13 will engage the outer end of wall 18 of the cylinder 17, therebyforcing the whole cylinder downwardly.

` Referring to Fig. 2, this action has the effect of moving the packing means 28 closer to the packing means 27 thereby decreasing the volume V of the confined space. Furthermore, this action will decrease the volume of the chamber 22 by virtue of the plunger 23 being secured to the tubular member 24 which is in turn locked by the spear slips 32 to the casing. Thus the fluid in chamber 22 will be forced down the passage 37 into the conned volume V further increasing the pressure of fluid in this space. Fluid from chamber 22 cannot pass back up into chamber 21 because of the one-way action of the check valve 20. With this greatly increased fluid pressure in the conned space V, the liquid therein will be forced out through the perforations 11 with great force and this fluid dow will serve to clean these perforations. Figure 2 illustrates the relative positions of the piston 16, cylinder 17, and packing means 27 and 28 at the end of the down stroke.

On the upstroke of the drill pipe 12, the piston 16 and hollow piston rod move upwardly in the chamber 21 and during this action any duid above the piston 16 is passed out into the surrounding casing through the port 17.- More liquid from a source disposed at the surface of the well passes down through the pipe 12 and hollow piston rod 15 into the chamber 21 as the piston is raised.` When the piston 16 reaches the top of its stroke, it will engage the end wall 18 of the cylinder 17 and move the cylinder 17 upwardly. This action has the effect of eX- panding the' conned volume V and the volume of the 4 lower chamber 22 which expansion will cause fluid from chamber 21 to enter chamber 22 as the plunger 23 approaches the bottom of the cylinder due to the upward movement of the cylinder. On the next down stroke of the drill pipe 12. the process is repeated and pressure is again built up in the confined space V.

Figures 3 and 4 show a modification of the tool of Figures 1 and 2 useful for providing an extremely large suction to the perforations 11. This cleaning tool, however, may also be used as a simple pump. In Figures 3 and 4 the same reference numerals used in Figure l are employed to designate corresponding elements and detailed description of these components is therefore not necessary. As shown, `the structure vis identical to the structure of Figures 1 and 2 except for the reversal of the two one- way valves 14 and 20 these valves being designated 40 and 41 in Figures 3 and 4 and shown operable in the opposite direction.

In the operation of the device of VFigures 3 and 4, the tool is set opposite the perforations to be cleaned as in the case of the tool of Figure 1. During the sucking operation, however, no fluid is introduced down through the 'drill pipe 12, but rather the drill pipe is simply reciprocated and serves as a conduit for conducting uid sucked olf the chamber 22 from the chamber 21. When piston inventionV will occur to those 16 reaches the end of its downward stroke, as shown in Fig. 4, the shoulder 13 on the coupling 13 will engage the end of wall 18 of the cylinder 17 forcing the cylinder downwardly and causing the confined volume V to be decreased due to the movement of the movable packing means 28 towards the stationary packing means 27. This action forces iluid in the confined space V up through the passage 37 in the tubular member 24 into the chamber 22, past the check valve 41, into the chamber 21, and thence through hollow piston rod 15 and drill pipe l2 to the surface.

On the upstroke of the piston 16 and piston rod 15, a partial vacuum will be created in the chamber 21 thereby sucking fluid fromchamber 22 up past the check valve 41 and also sucking fluid from the confined space V up through passage 37y in the tubular member 24. When the piston 16 engages the upper end of wall 18 of cylinder 17, the cylinder will then be moved upward thereby increasing the volume of the confined space V and thus creating a further suction therein. Oil or other lluids which lie behind the perforations in the formations will thus be sucked through the perforations 11, passed up through the passage 37, and subsequently through the drill pipe 12 tothe surface.

It is to benoted that'in each of the described embodiments a two-fold action takes place. First, a pressure or suction is built up by means of the piston 16 operating in the upper chamber of the cylinder 17. Secondly, a further pressure or suction is created by movement of the movable packing means 28 with respect to the stationary packing means 27. A further pressure or suction associated with these two is built up in the chamber 22 by the action of plunger 24. `It is because of this compound effect of'building upvpressure or suctionY that a greatly improved cleaning operation is realizable with this too It is to be noted that by virtuek of the fact that the cylinder 17 in Fig. 1 is made in two sections connected by the coupling 19,1`check valve 20 may be easily reversed. lSimilarly the coupling 13may `be removed, and the check valve 1'4 reversed. Thus the same tool may be used for a sucking or pumping operation.

Various modications within the spirit of the present sk illed in the art.

Iclaim: 31. In.' an apparatus'for cleaning perforations in oil wells, means for creating a uid pressure across said perforations Ibetween a conned space and the exterior of the casing, comprising in combination: a stationary packing means adapted to 'be secured -W-ithin and held stationary 4with respect to said casing; a movable packing means spaced from said stationary packing means to dene, with said perforated casing and said stationary packing means, said confined space; a cylinder secured to and movable with said movable packing means; a plunger means slid'ably receiving said cylinder and including a tubular member secured to said stationary packing means; a oneeway check valve ydividing lsaid cylinder into two chambers, said plunger means being operable in one of said chambers; a piston means reciprocably receivable in lthe other of said chambers and including means engaging said cylinder at ythe extremes of the stroke of said pis-ton means whereby yfurther movement of said piston means moves said cylinder; a one-way check valve in said piston means; fluid communicating means between said conned space and said one chamber; means for reciprocating ysaid piston means; and means providing a source o'f fluid communicating `with the said other chamber through said piston means.

2. The ysubject matter of `claim 1 wherein `said firstmentioned check valve comprises a Valve member which is seated by lilu-id pressure in said one chamber and the other check valve comprises a valve member lwhich is seated 'by iiuid pressure in the other chamber.

3. The subject matter of claim l ywherein said vfirstmentioned check valve comprises a valve member lwhich is unseated by fluid pressure in said one chamber and the other check valve comprises a valve member which is unseat/ed `by iluid pressure in the other chamber.

4. Apparatus for cleaning perforations in well casings, comprising in combination: movable and stationary packing means positionable within and in sealing contact with a perforated Well casing at opposite sides of perforations therein, -a cylinder extending axially of and vsecured to the movable packing means, means for securing the stationary packing means in fixed position lwithin the casing, means movably connecting said stationary packing means and cylinder for movement ofthe latter and said movable packing means toward and limited movement away yfrom said 'stationary packing means, plunger means axially movable in said cylinder, means for limiting movement of the plunger means in the cylinder, said plunger means including a tubular member having means Ifor attachling the member to a tubing string for reciprocating Ithe plunger means from the surface, movement of the tubular member in an axial direction with -said stationary packing means held stationary initially moving said plunger means to one limit of its movement in the cylinder and thereafter moving the movable packing means toward the stationary packing means, movement of said tubular member in the opposite direction initially moving the plunger means to the other limit of its movement in the cylinder and thereafter moving t-he movable packing means away from the stationary packing means, said cylinder having a transverse wall -dening with said plunger means a chamber which is decreased in volume by movement of the plunger means toward said one limit and increased in volume =by movement of the plunger means toward said other limit, said tubular member having first fluid passage means communicating at one end to said chamber and open at the other end `for communication to the interior of a tubing string `secured thereto, -there vbeing second iiuid passage means communicating said chamber to the space between said packing means, and one way check valve means in said tirst passage means.

5. The subject matter of claim 2 wherein `said check valve means comprises a valve member which is seated by iiuid pressure in said chamber.

6. The ysubject matter of claim 2 whereinsaid check valve means comprises `a valve member which is unseated by `fluid pressure in said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,919,350 Wickersham July 25, 1933 2,052,006 Taylor Aug. 25, 1936 2,077,022 Spencer et al. Apr. 13, 1937 2,159,023 Hayward May 23, 1939 2,290,441 McGaey July 21, 1942

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