US2290441A - Well cleaning device - Google Patents

Description

3 sheets-smeet 1 July 21, A1942. E. 'w. McGAFFY WELL CLEANING DEVICE Filed June 23, 1959 5226A@ WMGAF/rev,

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July 21, 1 942. E. w. MGGAFFEY WELL CLEANING DEVICE Filed June 25, 1959 3 Sheets-Sheet 2 @www July 21, 1942. E. W. MCGFFEY WELL CLEANING DEVICE Filed June 25, 1939 3 Sheets-Shea*l 3 Patented July 2i, 1942 WELL cLEANmG DEVICE Edgar W. McGaffey, Long Beach, Calif., assigner to McGafley-Taylor Corporation, Bakersiield, Calif., a corporation of California Application June 23, 1939, Serial No. 280,735

(c1. 16s-2o) 25 Claims.

y This invention relates to the production of petroleum from wells, more particularly to the cleaning of those wells, and the perforatlons in the casing or strainer, to enhance the ilow of oil into the casing.

As is well known to those engaged in the art of production of oil wells, a well consists of an imperforate casing extending to the oil sands, at which point the casing is perforated. The oil iiows into the casing through these perforations, whence it is lifted to the surface.

In the course of time, the perforations in the casing become clogged with mud, sand, tar, parafne, shale, and other more or less solid debris, which inhibits the iiow of oil into the casing.

Not only the perforations, but valso the formation adjacent to the perforations, collects this debris, retarding ow into the casing.

It is the general purpose of this invention to clean the periorations and the formations of this accumulated debris.

Apparatuses of various kinds are employed in the well cleaning art. Some of these include spaced packers which, upon being lowered into a well, form with the casing a confined chamber in the zone of the perforations desired to be cleaned, in which chamber iluid is placed under pressure, either by moving one packer toward the other, or by other well known means.

In these previous devices the working stroke between the packers is necessarily short, permitting operation upon a small area only of the perforated casing upon each setting of the tools. Inasmuch as a producing zone is often several hundred feet in length, it can be readily seen that such devices must be set in a large number of positions to clean the entire well. As production ceases during the cleaning process, it can be readily appreciated that the time consumed in cleaning should be as short as possible.

In United States Patent No. 2,159,023, granted May 23, 1939, entitled Well cleaning device, there is described an apparatus for cleaning wells, which has as its distinguishing feature a pair of packers, movable with respect to the casing, but with a constant spacing with each other, forming a chamber with the casing, in which chamber pressure is built up or lowered, as the packers travel unitarily up and down the` casing. Such construction oiers the advantage of making possible the washing of a greater section of casing for each setting of the tool, and also other advantages outlined in the patent, and it is a purpose of this invention to attain those advantagesand several others.

It is a further object of this invention to provide a wellcleaning device which is capable of cleaning the perforations of a well to the very bottom of the well.

It is a further object of this invention to provide a means for use in treatment of wells, which will permit the discharge of a predetermined charge of treating material vuniformly through the perforations (so many gallons per linear foot of casing). t

It is a further object of this invention to provide an improved structure which sets up a suction in one part of the casing, and a pressure in another, which causes circulation through the perforations and the formation outside of the casing.

It is a further object of this invention to provide a well washing device which will permit the traverse of a pair of packers during the working stroke of the cleaning with no large diameter parts moving with the packers in communication with the casing.

It is a further object of this invention to provide a structure which will permit pressure or suction or both, to be applied to a given zone of the casing during movement of the device without the necessity of alternating suction with pressure.

It is a further object of this invention to provide a structure in which flow in any given chamber formed by a pair of packers is always in one direction, i. e., from or to the formation.

n is a further object of this invention to provide means whereby uid and debris removed from the well perforations can be discharged at the bottom of the well for removal with a bailer or the like, to prevent sanding up of the apparatus used to remove the paraine from becoming clogged during the cleaning process.

This invention possesses many other advantages and has other objects which may be made more easily apparent from a consideration of several embodiments of the invention. For this purpose there are shown a number of forms in the drawings accompanying and forming part of the present specification. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of theiminvention ls best ldelned by the appended c a s.

Referring now to the drawings:

vention, partly in section.

Figures 2 and invention; and,

Figures 3 and 3a represent a third form of my invention. t

In general, the different forms may be assigned these different functions: Figures 1 and 1a represent a form which generates a pressure in one zone, and a suction in another, while Figures 2 and 2a represent a form which generates a pressure in the working zone adjacent the perforatlons being cleaned, and Figures 3 and'3a represent a form which generates a suction at the zone being acted upon. h

Referring to Figures 1 and 1a, the casing of the well undergoing treatment is; illustrated by I9, and h'as perforations or openings II for com. munication with the production. The tool embodying the present invention is shown supported within said casing by means of a tubing string or drill pipe I2, to which an upper tubular section I4 of the tool is secured by a coupling I3. The coupling is provided with a port I3' and the sec- 4 2a represent another form of my tion I4 with a check valve I5 permitting the passage of fluid from the exterior of the tube I4 to the interioronly.

Slidingly attached to th'e tube I4 is a working cylinder I6, the upper end of which is provided with a conventional cylinder head and stumng box I1, permitting relative movement between the cylinder and the tube I4 but preventing leakage of fluid between the tube and the cylinder. The lower end of the cylinder head-stuiiing box assembly I1 is provided with a clutch face I9 adapted to cooperate with a mating clutch face I9' of a coupling I8 attached to the tubing I4, to provide for rotation of the cylinder I6 and tube I4 as a unit for a purpose which will hereinafter be described.

The coupling I8 supports a nipple 20v, containing a check valve 2I which permits flow of fluid in a downward direction only. Connected to the nipple is a tube 22, upon whichis mounted a piston 23, held in place between a flange 24 and a coupling 25 secured to the tube 22 above and below the piston, respectively. The lower end of the tube 22 is blanked off at 26, and communication between the interior of the tube 22 and the space in the cylinder below the piston is established through the port 21. A small tube 28 is secured within the tube 22 and extends from the space in the cylinder above the piston through the blanked off portion of the tube 22.

Connected to the coupling 25 is a tube 29, extending to the Ivery bottom of the apparatus, and equipped at its lower end (Figure 1a) with a valve 30, which permits passage of fluid from the tube interior to the casing only. This tube 29 is blanked on at its upper end, as at 3I, and a tube 32 secured within the tube 29 extends through the plug or partition 3I, providing in effect a continuation of the tube 28. Tube 29 is provided with a port 33communicating with the space in the cylinder I6 below the piston 23. The lower end of the cylinder carries a, cylinder head and stuiling box 34 by which' it is slidably attached to the tube 29, and which prevents leakage of fluid between the tube and cylinder.

A down drive spear or anchoring mechanism, generally designated A, includes a slip expander 35 connected to cylinder head` 34 and by which the mechanism A is supported from the cylinder head 34. The slip expander is provided with downwardly and inwardly tapered portions 35 mounting slips 36 having casing engaging teeth so arranged that upon downward movement of 75 r to stationarily support the expander and attached cylinder I6 therewithin'.

In order to permit setting of the slips at any selected position in the casing, a tube 31A is attached to the slip expander 35 and slidably mounts, a sleeve 39 having a bayonet slot 49 engageable by a pin 33 secured in tube 31 and extending thereinto from the tube 31. When the pin is in the horizontal leg of th'e bayonet slot, the slips are positioned inietracted position on the expander 35 and away from the casing. However, when it is desired to set the slips the tubing I2 may be rotated, causing the cylinder I6 to rotate through the engaging clutch faces I9, I9', whereby to rotate the tube 31 and move the pin 38 into alignment with the vertical leg of the bayonet slot. Frictional engagement between the springs42 and the casing is sufficient to support the slips when the pin is so aligned, and it will be seen how downward movement ofjthe tubing I2 will effect a corresponding movement of the cylinder I6, and movement of the expander relative to the slips to eflect `their wedging between said expander and casing. Such wedging action insures a stationary mounting for the cylinder I6 during the washing operation hereinafter fully described.

Referring again to the tube 29, said tube carries on its lower portion three packers 43, 44, and 45, in fixed spaced relation (Figure 1), saidpackers being of any suitable type. The packers 43 and 44 define a chamber P with the well casing I I and the packers 44 and 45 define a chamber S with said casing, packer 44 being the common one toboth chambers. During operating conditions which will hereinafter be described, a fluid pressure is developed in the vspace P, forcing fluid outwardly therefrom through the vcasing perforations, while a suction is simultaneously established in the space S, causing th'e flow of fluid into said space through the perforations, such simultaneous action taking place during the unitary movement .of all three packers Within the casing. 'I'he particular packers shown are so constructed and arranged that fluid is prevented from escaping from the high pressure chamber P past the packers 43 and 44, while fluid is also prevented from entrance into th'e suction chamber S past the packers defining it. Packer 44 being common to both chambers, need only have its high pressure side directed upwardly, and performs its function as desired.

The means for mounting the packers in fixed spaced relation on the tube 29 may be conveniently done by providing spacer sleeves on the tube between the packers, and holding said packer and sleeve assembly between the flange or collar 4B fixed to the tube 29 and the valve body 3U' secured to the lower end of the tube.

Communication is had between the space P and th'e space in the cylinder I6 below the piston 23, through a port 41 between the packers 43, 44, tube 29, and port 33. A valve control port 48 is provided between the packers 44 and 45, permitting passage of fluid from the space S to the interior of the tube 29 only. The tube 29 is blanked on above the valve controlled port 48, as indicated at 49, and the lower end of the tube 32 extends through said partition or plug 49 in communication with the tube interior therebelow. Thus, a passage -is established from the space S and th'e interior of the cylinder I6 abovethe piston 23, through the valve control port 49, tube 32, and

tube 28. Inorder to permit movement of the entire device through a fluid filled well, a by-pass 50 is provided within the tube 29 which extends from a point in the tube 29 above the packer 43 to a point below the packer 45.

In detail, the operation of the apparatus is as follows:

The apparatus is lowered into the well with the pin 38 in the horizontal leg of the bayonet slot 40 and the slips in retracted position, until the portion of the perforated casing desired to be cleaned is reached. At this point, the tubing string I2 is rotated, which, because of the engagement of the clutch elements I9, I9', rotates the cylinder I6. This rotates the tube 31, and because the springs 42 frictionally engage the casing walls, holding the sleeve 39, the pin 38 can travel tothe vertical leg of the slot 40. Further lowering of the tubing string I2 will engage the slips 36 with the casing through the action of the slipv expander 35, thus holding the cylinder immovable. The tube I2 is then worked up and down within the stroke of the device, and piston 23 and tube 29, with the three packers, move with it. During the down stroke of the piston, the uid between the two lower packers, or space S, travels through the valve controlled port 48, up tube 32 and tube 28 to the space in the cylinder above the piston. At the same time, fiuid from below the piston travels through the port 33, down the tube 29, and out ports 41, creating. a iiuid pressure in space P. Upon the upstroke, uid from the cylinder above the piston travels down tubes 28, 32, and out through the valve 30, driving such debris-laden fluid as may have collected in the lower part of tube 29 with it. At the same time, fluid from the casing I flows through the port I3' or the valve I5, into tubing I4, downwardly past the valve 2|, into the short tube 22, and out of port 21 into the space in the cylinder below the piston.

It should be noted that the port I3 is omitted when washing with chemicals introduced down the tubing string I2. In such a case, the washing uid is introduced into tubing I2 and upon the upstroke flows downwardly past valve 2l into the tube 22, out port 21 into the cylinder below the piston, and thence, upon a downstroke, through port 33, down tube 29, out ports 41 into the space P. When the fluid introduced is exhausted, uid will flow into the tubing I4 from the casing space through valve I5. It is seen therefore that valve I5 is used and port I3 omitted, only when it is desired to wash with chemicals introduced from the surface, but, if washing with the well fluid is desired, the valve I5 does no harm, but port I3 is provided to permit iiuid to ow readily from or to the tube I4.

In connection with this form of device, it should be noted that as the packers are moved, the action on any perforation is a violent reversal of flow as the middle packer passes that perforation or more exactly, a horizontal row of them. This reversal, if the pressure is high enough, is, so far as the perforations are concerned, almost a blow, and is most efficacious in loosening the obstructions in the perforations and their surrounding formation. Yet, to obtain this blow, as it acts on only a small number of perforations at any one time, no destructive forces are built up, endangering the equipment and the well.

As heretofore explained, Figures 2 and 2a show a form of the device utilized when pressure washing only is desired. The construction oi' this device is similar in many respects to that shown in Figures 1 and la, with many parts corresponding to those in these figures.

The tool is shown supported within the perforated casing I0 on the end of the tubing string I2, as in Figures 1 and 1a. Coupled to the tubing string by coupling 5I, containing port 52, is a tube 53 having a valve controlled port 53' permitting entry of i'luid into the interior of the tube only. A cylinder 54 is provided with a cylinder head and stuiiing-box 55 and slidably receives tube 53, the lower end of which is provided with a coupling 56, said coupling and cylinder head having cooperative mating portions, as explained in connection with Figure 1.

The coupling 56 is ported at 51, establishing communication between the tube 53 and the upper portion of the cylinder 54. Above and below this port are two valves, 58and 59, allowing downward passage of fluid only' The lower valve body provides a connection' between the coupling 4 56 and the tube 60, upon which the piston 6I is mounted between the flange 62 and coupling 63.

Said coupling is ported at 64, and supports tube 65 extending to the bottom of the apparatus.

The lower end of the cylinder 54 is provided with a cylinder head stuffing box 34 slidably receiving the-tube 65; and a spear or anchoring mechanism is connected with said cylinder head for stationarily supporting the cylinder within the casing when desired as explained in connection with Figure 2.

Two packers 66 and 61 are mounted in fixed spaced relation on the lower end of the tube 65 in the manner explained in Figure 1, and ar'e arranged so that they may allow pressure to be built up in the chamber P they form' with the casing. Said chamber is communicative with the interior of the ltube 65 through the port 68 between the packers. In order to permit movement of the tool in a fluid lled well, a by-pass 69 is provided around the packers. In this form, the bottom of the tube 65 is closed as by the cap 10.

Operation of the device, so far as manipulation is concerned, is identical with that described in connection with Figure l. However, reciprocation of the tubing string I2 produces pressure only in the space P', as will become apparent from the following explanation.

The cylinder 54 is set in position through actuation of the anchoring mechanism, and upon downstroke, fluid flows through the port 52 or valve 53 into tube 53, downwardly past valve 58 and through port 51 into the space in the cylinder above the piston. At the same time, iluid ows from the space in the cylinder below the piston through port 64 into tube 65, down tube 65, and out through ports 68 into the space P', between the packers. Upon the upstroke, fluid flows from the upper part of the cylinder through port 51, through valve 59, down tube 60, and out port 64 into the lower part of the cylinder.

This particular form of device can very accurately spot chemical on the walls of the well through the perforations if the valve 53' and port 52 are omitted. The device is set dry, and the desired amount of chemical poured in, care being valve 63 isv used, and when the fluid from the surface is exhausted, the well uid enters the valve 53' for continued washing.

A third variation of operation is to utilize the well fluid alone, in which case prts l2 allow the fluid to enter lthe tube I3 for driving down through the cylinder into the space between the packers.

Figures 3 and 3a show a third variation of Astructure which is utilized to create a suction washing only at the zone in the weil being treated.

In this form of device, the structure is suspended in the well casingv I8 by the string I2, as before. Attached to the end of the tubing string by the coupling. 10 is a tube 1I, passing into a cylinder 12 through its upper head and stuffing box assembly 1I which permits sliding movement of said tube. The lower side of the cylinder head 13 is provided with a mating surface adapted to cooperatively engage a complementary surface on the coupling 14 secured to the lower end of the tube 1l for effectingunitary rotation of the tube and cylinder. Tube 1l has a valve 15 therein permitting upward flow only.

Attached to the coupling 14 is another tube 16, which supports the piston 11 as described in connection with Figure 1. Tube -16 is blanked oif at its lower end, and a small tube 18 passes through the wall of tube 16 and said blank end. A valve 16 permits iiow of fluid from the cylinder 12 to the interior of the tube 16 only, is provided in the wall of 16.

Below the piston, tube 16 is coupled with another tube 19 by coupling 80, which coupling has a port 8| -above the blanked oi end of tube 16, establishing communication between the space inthe cylinder below the piston and the interior of the tube 16. Tube 19 extends through the lower cylinder head stuillngbox assembly 82 to the bottom of the apparatus. Said cylinder head supports an anchoring mechanism whose construction, arrangement of parts, and function are similar to those described in connection with the corresponding mechanisms heretofore described.

piston ows through the "port Il' into tube 16, up Dastvalve 16, and thence to the surface, or

else-out into the well at some point in the tubing string, although it is an advantage to keep it out of the -well as it may contain debris of various sorts. ,At the same time, the fluid in the space S between the packers flows through the port 85 to the interior of the tube '19, up said tube, and through small tube 18 into the space within the cylinder above the piston, creating a suction between the packers.

Upon the upstroke, the iluid in the upper part of the cylinder flows through valve 16' into the interior of the tube 16, and down 16, through port 8| into inder..

I wishhvto point out in -connection with all three forms that in the event a blank place in the pipe is encountered, the device can be un- 20 locked from the pipe orcasing on an upstroke,

. packers.

At its lower end,tube 19 mounts a pair of packers of relatively fixed spaced packers 83 and 84 which are arranged so thaty their low pressure sides are adjacent to each other, thus forming a chamber S' with the vcasing within which a suction can be maintained. Communication between the space S and the interior of the tube 19 is provided by port 85, to permit passage of fluid from said space to the interior of tube 19. Ihe packers 83 and 84 are mounted on tube 19 as in Figures l and 2, mechanically speaking, be-

i tween the flange 86 and the cap 81 on the end of the tube 19.

A by-pass 88 is provided for passage of well uid past the packers during movement of the device to prevent swabbing and tearing of the packers.

The manipulation of the device is similar to those o! Figures 1 and 2. However, the eiect on the perforations is diierent, as will hereinafter appear. Once the cylinder is set, upon for the downstroke is the only workingstroke building up or decreasing pressure betweenthe Without an arrangement permitting this, it would be difficult if not impossible to move the device if a blank length of casing or one tightly plugged were attempted tobe washed. Application of force would build up suilicient pressure to blow the packers, or else part the string, either f which, particularly the latter, is an expensive matter to remedy, because of time lost on the round trip and. for fishing.

I wish to further point'out that the spacing between the packers may be reduced by setting them closer together, so that a given displacement of the piston will produce as great a velocity as desired through the perforations. Inasmuch as the speed of reciprocation of the piston is limited by the mass of the suspending tubing string, its elasticity, and the capabilities of the surface equipment, as inordinary deep well pumps, it may well happen that the pressures and suctions produced by the maximum speed of reciprocation obtainable is insufficient to produce the cleaning eiIect desired.' In such an event, setting the packers closer will reduce the number of perforations acted upon at any one ins tant, which, of course, means a greater velocity through the perforations being acted upon, but, at the same time, there will be little reduction in the number of perforations washed at one setting of the slips, as the travel of the piston and packers determines the footage washed. This is in contradistinction to prior devices with stationary packers, in which a reduction in packer spacing reduces the footage washed per setting proportionately to the reduction in spacing, and is in contradistinction to devices which depend upon packers moving with respect to each other for creation of pressure, in which, of course, a reduction of spacing means a reduction of both the stroke and footage washed per setting.

Iclaim:

1. In a device for cleaning the perforations in a pipe or the like, means creating a zone of high pressure against the perforations, means creating a zone of low pressure against the perforations of the pipe, separating means between the zones of high and low pressure, and means moving said separating'means with respect to the pipe while maintaining said zones of high and low pressure substantially constant in extent, whereby the passage of the separating a down stroke the uid in the cylinder below the f2. In a device for cleaning the perforations -the lower part f the cylin la pipe or the like, means forming a pair of confined chambers of fixed column within the pipe, means mounting said packing means for movement with respect to the pipe, and means operated by movement of the packing means with respect to the pipe, for increasing the pressure Ain one confined chamber and decreasing the pressure in the other confined chamber formed by the packing means.

3. In a device for cleaning perforations in a pipe or the like, packing means cooperative with the pipe to create two confined chambers of fixed volume, means mounting said packing means for movement with respect to the pipe, a cooperative plunger and cylinder, the opposite ends of said cylinder being in communication with the confined chambers, and means moving said plunger relative to said cylinder whereby the increase in pressure at one end of the cylinder is communicated to one confined chamber and the decrease in pressure at the other `end of said cylinder communicated to the other confined chamber.

4. In a device for cleaning perforations in a pipe or the like, packing means cooperating with the pipe to form a coniined chamber of fixed volume, means mounting said packing means for movement relative to the pipe, a cooperating cylinder and plunger, communication between the cylinder and the confined chamber, means mounting the cylinder xed relative to the pipe, and means mounting the plunger for movement relative to the cylinder upon movement of the packing means with respect to the pipe.

5. In a device for cleaning the perforations in a well, packing means cooperating with the pipe to form a coniined chamber therein, a. cooperative plunger and cylinder, means iixing said cylinder with respect to the pipe, a tube, means connecting said tube to said plunger. and the packing means, and an opening in the Wall of the tube within the space dened by the cylinder, another opening in the wall of the tube within the confined chamber formed by the packing means, and means for moving the tube, whereby to move the packing means relative to the pipe and the plunger relative to the cylinder, and whereby the change in pressure in the cylinder engendered by the movement of the plunger with respect thereto is transmitted to the conned chamber formed by the packing means.

6. In a device for cleaning perforations in a pipe or the like, packing means, forming a confined chamber of xed volume in the pipe, means mounting said packing means for movement with respect to the pipe, a cooperating plunger yand cylinder, forming a pressure changing means, means mounting one element of the pressure changing means for movement with the packing means, means removably mounting the other element in xed relation to the pipe, wherebythe movement'of said packing means moves one of said elements with respect to the other,` means transmitting the-change in pressure engendered by movement between said elements to the chamber formedby the packing means, said means operating upon movement of the packing means in one direction only, and means releasing the xed element of the pressure changing -means upon continued movement of the packing means in the other direction.v

'7. In a device for cleaning perforations in a pipe or the like, means mounting packing means movable with respect to the pipe, said packing means forming a confined chamber of fixed volume therewith, a cooperating cylinder and plunger forming a pressure changing means, means mounting said cylinder against movement in one direction in the pipe, and means mounting said plunger in iixed relation to said packing means, a passage from one end oi' s'aid cylinder to the confined chamber formed by said packing means, said passage being operative to transfer a change of pressure engendered by movement of the plunger with respect to the cylinder to the conned chamber formed by the packing means, and another passage communicating with said end of the cylinder open upon movement of the plunger in the direction in which the cylinder is free to move, whereby upon movement of the plunger and packing means in that direction the cylinder may be moved upon engagement of the plungerpacking means assembly with the cylinder without change of pressure in the conned space formed by the packing means.

8. In Ia device for cleaning the perforations in a pipe or the like, packing means forming a confined chamber of iixed volume in the pipe, means moving said packing means with respect to the pipe, a cooperative cylinder and plunger, means moving said plunger with respect to the cylinder upon movement of the packing means with respect to the pipe, a passage from one end of the cylinder to the confined chamber, a passage between the ends of the cylinder, Iand a passage from the cylinder not in communication with the confined chamber to a source of uid to be injected through the perforations of the well, and means closing said second-mentioned passage upon movement of the plunger with respect to the cylinder in a direction to force fluid into the confined chamber, and means closing said thirdmentioned passage upon movement of the plunger in an opposite direction, whereby to cause fluid to be forced into the conned chamber only after it has been drawn into the cylinder.

9. In a device for cleaning the perforations of a pipe or the like, packing means forming a conned chamber of fixed volume in the pipe, means mounting said packing means movably with respect to the pipe, a cooperative cylinder and plunger, means connecting said plunger to the packing means for movement with respect to the cylinder upon movement .of the packing means with respect to the pipe, a passage connecting one end of the cylinder with the conned chamber, a passage from said confined chamber, means closing said first-mentioned passage upon movement of the plunger relative to the cylinder to decrease the volume at said end of the cylinder, and means closing the other passage upon movement of the plunger in the opposite direction. f

10. In a device for cleaning the perforations in a pipe in a well or the like, packing means forming a conned chamber in the pipe, means mounting said packing means, a cooperative cylinder and plunger, means moving said plunger with respect to the cylinder, a passage from one end of the cylinder to the conned chamber, the volume of said passage being large in comparison to the displacement of the plunger inthe cylinder, a passage from the first-mentioned passagfto a space below the packing means, means closing said rst-mentioned' passage upon motion of the plunger to decrease the volume at the mentioned end of the cylinder, and means closing said second-mentioned passage upon movement of the plunger in an opposite direction, whereby fluid from the space within the conned chamber does not pass into the cylinder upon operation of the device. i

' side oi' the plunger, means forming a discharge outlet from the portion of the cylinder on the opposite side of the plunger, means forming communication between thetwo portions of the cylinder, Ameans closing said discharge outlet upon relative movement of the plunger away from the end of the cylinder in which said discharge outlet is connected, and means 'closing said communication between the two portions of the cylinder upon movement in the opposite direction.

12. In a device for cleaning the perforations in a pipe or the like, packing means, means mounting said packing means for movement with respect to the pipe, said packing means cooperating with the pipe to form two conilned chambers of ilxed volume therein, a cooperating cylinder and plunger, said plunger being connected to the packing means for motion relative -to the cylinder upon motion of the packing means relative to the pipe, means forming communication between each of the conilned chambers and a portion of the cylinder on opposite sides of the plunger respectively, means forming an inlet passage to one portion of the cylinder, means forming an outlet passage from the communication between the other portion of the cylinder and the confined space, means closing said inlet and said outlet'I passages upon motion of the plunger in one direction, and means closing the last mentioned communication means on motion of the plunger in the other direction.

13. In a device for cleaning the perforations in a pipe in a well or the like, packing means, means mounting said packing means, said packing means cooperating with the pipe to form a conilned chamber therein, a tube leading to the surface, a cooperative cylinder and plunger, means eiecting relative movement between the plunger and cylinder, means forming communication from the tube to the cylinder, means forming communication from the cylinder to the confined chamber, valves in said communications so arranged that operation of the cylinder and plunger assembly forces iiuid from the tube into the confined chamber, and a one way valve in the wall of the tube permitting ow of uid from the interior of` the pipe to the interior of the tube only, whereby said tube can be utilized to introduce `iluid to the conned chamber, and, when that iluid is gone, uid contained in the Well may enter the tube and be introduced into the coniined chamber.

14. In a device for dosing casing perforations and formation oi a well, packing means forming ac onilned chamber of xed volume, means mounting said packing means, and means moving said packing means relative to the casing, said packing means thus defining a coni-lned chamber with the casing which can be moved with respect 'to the casing, and a positive displacement pump, means connecting it to the packing means and the casing, and a passage from a source of dosing iluid to the pump, whereby upon moving the packing means with respect to the casing the pump forces a charge of dosing fluid into the conned chamber, said charge being of a definite volume for a given motion of the packing means.

15. In a device for cleaning perforations in la I pipe in a well or the like, packing means. cooperating with the pipe to form a conillned chamber of ilxed volume therein, a cooperative cylinder and plunger above the packing means, means lixing the cylinder to the walls of the pipe, and

Vmeans connecting the plunger to the packing means, means moving the packing means and plunger with respect to the pipe and cylinder, and a passage from the cylinder to the coniined chamber to transmit the change in pressure induced by movement of the plunger to the coniined chamber.

16. In a device for cleaning perforations in a pipe in a well or the like, a pair of packing members, a cooperative cylinder and plunger thereabove, a tube mounting said plunger and said packing members, means fixing` said cylinder to the walls of the pipe, and passages through the tube from the interior of the cylinder to between the packing members, whereby the movement of the plunger, tube, and packing assembly causes -a change in pressure in the cylinder to be trans- 'mitted to the space between the packing members to act upon the perforations of the pipe.

17. In a device for cleaning perforations in a pipe or the like, packing means forming a pair of conned chambers ofk fixed volume within the pipe, means mounting said packing means for movement with respect to the pipe, and means for increasing the pressure in one confined chamber and decreasing the pressure in the other conllned chamber during movement of said space deilning means with respect to the pipe.

18. In a device for cleaning perforations in a pipe or the like, packing means forming a confined chamber of ilxed volume. within the pipe,

` means mounting said packing means for movement with respect to the pipe, a pump exteriorly of the confined chamber for generating a pressure within the pipe, means supporting said pump above the packing means, and means-providing communication between the pump and the conned chamber, whereby the pressure generated by the pump may be transmitted to the perforations in the pipe opposite the conilned chamber- 19. In a device for clearing perforations in a well casing, a pump positioned in a well, packing means forming a confined chamber within the casing of constant volume but movable therein, said packing means being disposed below the pump, said pump being operatively connected with the chamber for effecting movement of fluid between said chamber and pump during movement of said packing means with respect to the casing.

20. In a device for creating a ilow in a pipe or the like, a cylinder and cooperative plunger, means forming a passage through the cylinder and plunger, a pair o! valves in said passage permitting ilow of iluid in one direction only, and means forming a second passage communicating with the first passage intermediate the valves and with the interior oi' the cylinder.

21. In a device for creating a pressure in a pipe or the like, a cylinder and cooperative plunger,

valves communicating with the other end o! the cylinder.

22. In a pipe perforation cleaning device, a

pair of packers in fixed spaced relation, a third packer therebetween, means causing said third packer to traverse the pipe being cleaned, means maintaining a high pressure between one of said pair of packers and the third packer, and means maintaining a 'low pressure. between lthe other of said packersand the third packer during the traverse of saidA thir'dpacler. Y ,y

23. A device .foriorcixig tluid againstl a perforated casing in a well confini'ising;;'a kcooperative plunger and cylinder withintliefwell, operatively connected to saidplungerzandextending to the surface of the mndreclip- 24. A device for forcing fluid against a perforated casing in a well comprising a cooperative plunger and cylinder within the well, a tubing comprising a source of fiuid and extending through one end of the cylinder and through the plunger into the other end of the cylinder, said tubing being operatively connected with said plungery and reciprocable for causing relative movement between the cylinder and the tubing, a pair of valves in raid tubing the upper one of which permits ow from said tubing into thecylinder only and the lower one of which permits flow from said cylinder into said tubing gonly', and a passage intermediate said valves com- -xfnunica'ting between said tubing and the iirst mentioned end oi the cylinder,

25.1n. a .device of the kind described, a pump adapted to be lowered into a well on a tubing string, means for positioning the pump in the wall, said pump being operably connected with said tubing string and operable by reciprocation of said tubing string, after being positioned in the well, a discharge tube leading from said pump and extending below said pump, and means connecting said tubing string to said discharge tube to reciprocate said discharge tube during operation of said pump, whereby the discharge from said pump is distributed over the walls of the well upon such l:peratiom EDGAR W. McGAFFEY.

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