US1510669A

US1510669A - Perforation cleaner for oil-well casings

Info

Publication number: US1510669A
Application number: US629621A
Authority: US
Inventors: Halliday Alonzo Lewis
Original assignee: Individual
Current assignee: Individual
Priority date: 1923-04-03
Filing date: 1923-04-03
Publication date: 1924-10-07
Anticipated expiration: 1941-10-07

Description

ch 7, 1924. I 1516669 A. HALLIDQY PERFORATION CLEANER FOR .n-z i. wsm, CASINGS Filed Ap fil '5; 1923 a Sheets-Sheet 2 F1 11;: 1% E 15 Patented Oct. 7, 1924.

UNITED STATES ALONZO LEWIS HALLIDAY, OF OIL CENTER, CALIFORNIA.

PERFORATION CLEANER FOR OIL-WELL CASINGS.

Application filed April 3, 1923. Serial No. 629,621. I

To all whom it may concern:

Be it known thatI, ALoNzo LEWIS HALLI- DAY a citizen of the United States, residing at Cil Center, in the county of Kern and State of California, have invented certain new and useful Improvements in Perforation Cleaners for Oil-Well Casings, of which the following is a specification.

My invention relates generally to devices for cleaning oil-well casings in the region of their perforated sections and dislodging and disintegrating caked formation which lies around and in close proximity to the exterior surface of the casing.

My invention relates particularly to and consists in certain novel improvements in the perforation cleaner disclosed in my United States Letters Patent No. 1,474,630, issued Nov. 20, 1923, upon my application Serial No. 546,587, filed March 25, 1922, which said disclosure will necessarily be re peated herein to. an extent required for a full understanding of said improvements.

These improvements concern the arrangement and selective control of the ports through which the cleaning fluid is discharged, the stop feature by which the several positions of the selective control valve member are defined, a means for better holding the tool against possible rotation in the casing While operating said valve member, and changes in the construction of the several parts of the device which make for greater strength and ease of operation and longer life, all of which will be more fully described hereinafter with the understanding that changes may be made in the form and construction of the device as herein de scribed and illustrated, without departing from the spirit of the invention as expressed in the claims hereto appended.

The object of my present invention is to provide a simple and effective well cleaner, which is most universally practical owing to its capability of, coping with the different conditions encountered in different wells and in different localities, and which moreover can be readily understood by and is safe to entrust to the average well worker, and may be used in connection with the customary oil field equipment. More specifically, the object of my invention is to provide a well cleaner which may be used not only for cleaning the perforations in the well casing and for loosening the caked formation immediately exterior thereto, in the manner described in' my said pending application Ser. No. 546,587 but also for loosenmg and removing caked formation within and around the bottom of the casing, such for example as the caked mud which collects in the bottom and interferes with the production of a newly drilled well in which mud has been used in connection with the drilling operation, and for dislod ing and removing any accumulated ormation which may have settled above the device,

and which would tend to prevent its re moval. This latter function of my device may also be used to introduce fluid into the well above the cleaner, to counter-act, by its weight, the efl ect of fluid pressure below the cleaner, which might tend to elevate said cleaner and the tubing string to which it is secured. Further objects of my present invention are to provide means incorporated within the device itself to enable the operator at the surface of the ground accurately to determine the several positions of the selective control valve; to provide means for effectively enclosin the mechanism to pre vent the ingress o sand thereinto; to provide a simple construction. for relievin the control valve member of the weight 0 the entire device; and to provide means for enabling the device to be pulled out with the usual fishing tool in case it should become detached from the tubing string.

My well cleaner may be allowed to remain connected with the lower end of the tubing string in a flowing well, or with the bottom of the pump in a pumping well, the fluid passing through the device and into the pump or tubing string, thus saving the time and expense involved in pulling the tubing string whenever it becomes necessary to clean the perforated section of the casing.

My invention will now be fully described with reference to the accompanying drawings, wherein: v

Fig. 1 is an elevation of my device suspended within the perforated section of a well casing, the casing being shown in section.

Fig. 2 is a partial central longitudina section of my device.

Fig. 3 is an elevation of the upper portion of the valve tube, the stop rings being shown in section.

Fig. 4 is a horizontal section taken on the line 4-4 of Fig. 3.

Fig. 5 is anelevation of the central portion of the mandrel,'the packers and retaining dog mechanism bei. shown in section, and certain portions 7" omitted for the sake of clearness.

Fig. 6 is a horizontal section taken in the' Y direction of the arrow on the line 66 of 10-10 of Fig. 12.

Figs. 11 and 12 are vertical sections of the same, taken respectively on the lines 11-11 and 1212 of Fig. 10.

Fig. 13 is a horizontal sectional depall, enlarged, of the stop for limiting the outward movement of one of the retaining do s.

ig.. 14: is a perspective view of one of the retaining dogs.

Fig. 15 is a part sectional plan, enlarged, of the stop pin holder rin shown in the upper WIMOII of Figs. 2 an 3.

Fig. 16 is a" perspective view of the stop Fig. 17 is a. diagrammatic projection of the stop ring cam and the mandrel, showing the relative positions of the stop ring notches and the, mandrel discharge orts. The ports of the valve tube are also s own, projected, in dotted lines. 1

Figs. 18 to 23, inclusive of both, are dia-, grams showing the arrangement of the open and closed ports in each operative position of the valve tube, the stop pin and a pro-- jection of the stop ring cam being shown in the upper portion, and a diagrammatic section of the mandrel and valve tube inthe lower portion, of each figure.

In the drawings, and referring for the moment to Figs. 1 and 2 thereof, the reference numeral 1 designates the perforated section of a well casing, the perforations being designated by 2. 3 is the tubing string, to the lower end of which my improved perforation cleaner is secured, and by means of which it is supplied with the cleaning fluid, and its valve member operated. The cleaner itself comprises 1 tubular mandrel 4:, which carries upper and lower spaced

packers

5 and 6 respectively, formedv of any suitable resilient material adapted to fit closely within the casing 1 to close the space between said casing and the mandrel 4. The lower packer 6 is retained between a nut 7 screwed upon the mandrel 4:, and a rin bears against a shoulder 9 forms upon said the latter being 8 which,

for convenience in assembling, and to pre vent mutilation of the parts. through the enforced use of pip wrenches. By holding the keyed ring 8 with a spanner wrench, the entire mandrel ma be held stationary while assembling or isantling its associated threaded parts.

.The upper, packer 5 is similarly mounted between a notched nut 12, threaded upon the upper end portion of the mandrel, and a retaining dog mechanism indicated collectivel in Figs. 1, 2, and 5' by 13, and which hears against a shoulder 14; formed upon said mandrel. The retaining dog mechanism 13 is provided for the purpose of engaging the perforations 2 of the casing 1, and thereby to prevent the rotation of a the mandrel 4 when the cleaner is in functional position; and is therefore prevented from rotating upon the mandrel t by a key 15, Fig. 5. Said retainin ,dog mechanism is illustrated in detail in igs. 9to ML, and comprises three

adjacent rings

16, 17 and 18, encircling the mandrel t and keyed thereto as above stated, and held together by screws 19, as shown in Fig. 12. An annular channel 20 is formed between the lower ring 16 and the middle ring 17 and in this channel are mounted horizontally swinging dogs 21. There are four such dogs shown in Fig. 9, arranged in pairs, the members of each air being disposed oppositely to each ot er.

However, the number "and arrangement of the said dogs 21 may be changed if practical considerations render it expedient, the essential point being that at least one such dog must face in each direction.

The dogs 21 are provided with oppositely extendin hubs 22, Figs. 11 and 14, which extend through and are journaled in holes in the spaced portions'of the

rings

16 and 17 The upper hub 22 of each dog extends into a channel 23 formed betweenthe mid-- dle ring 17 and the upper ring 18, and is provided with a transverse slot 24:, into which is fitted the end portion of a spring 25. There are two such springs for the four do arranged as shown in Fig. 10, each spring engaging two dogs. The springs 25 are retained inv position endwise by being bent part way around the screws 19 at their center portions, and by having their ends bent over outside 'the hubs 22, as shown at 26 in Fig. 10. The upper ring 18 retains said springs within the slots 24, as shown in F ig. 10 and 11. The outer half of the upper hub 22 of each dog 21 extends farther than the inner half, and is adapted to engage a shoulder 27 formed upon the under surface of the upper ring 18, to limit the outward movement of the dog, as shown in Figs. '11 and 13. Said shoulder 27 is flattened, as at 28, to permit the dog to have suflicient swinging movement. An annular guard 29,'F1gs. 10 and 12, encloses the space 23 between the

rings

17 and 18 to prevent foreign matter from entering. Y Y

The dogs 21 are normally held in such position by the springs 25 that their outer ends project slightly beyond the

rings

16 and 17, and bear against the inside of the casing 1, and in this position they are ready to engage the rforations 2, as shown at 30 in Fig. 9. uch an engagement as that shown at 30 would prevent the mandrel 4 from being moved within the casing in a clock-wise direction and a slight movement thereof in the opposite direction would cause one of the oppositely disposed dogs to similarly engage a perforation. Thus the mandrel 4 is effectively locked against all but a slight rotative movement in either direction. The ends of the dogs 21 are rounded in a vertical plane as shown, so that any vertical movement of the device causes the engaged dogs to be moved inwardly and freed from the casing perforations. This rounded form of the dogs 21 also prevents them from catching upon obstructions or joints in the casing when the device is being raised or lowered. The dogs 21 are also rounded in a horizontal plane, on an arc whose center coincides with the center of the hubs 22, so that there is no danger of said dogs becoming jammed in case two or more happen to engage perforations at the same time.

Returning now to Fig. 2, the mandrel 4 carries within it" a rotatable tubular valve member 31, which has a sleeve 32 permanently secured to its upper end, and said sleeve is provided with interior threads for engagement with the lower end of, the tubing string 3, as shown at 33. The nut 12 of the upper packer 5 carries an integrally formed sleeve 34, which extends upwardly, inclosing the parts within, and is provided with an interior shoulder 35 adapted to engage the upper end of the valve coupling sleeve 32. Thus the entire weight of the device is carried by said coupling sleeve 32, the outer sleeve nut 3412, and the mandrel 4, rather than by the valve tube 31. A set screw 36 is provided for retaining the sleeve nut 34--12 in position. The upper end portion of the outer sleeve 34 is provided on its exterior with flutes or beards 37 to enable the device to be engaged by a fishing tool in case the tubing string 3 should become detached. The lower end of the valve tube 31 is permanently closed by a plug 38, and the lower end of the mandrel 4 is closed by a removable plug 39, which forms a bearing for the bottom of the valve tube 31.

on different levels.

The mandrel 4 is provided with four distinct sets or groups of discharge apertures or ports, which'are selectively controlled by the partial rotation, or more properly the oscillation, of .the valve tube 31, said valve tube having similar groups of ports adapted tobe moved into and out of register, by said oscillation, with the ports of the mandrel. All the ports of each group are controlled simultaneously. The preferred arrangement of the mandrel ports is shown in full lines in the diagram of Fig. 17 which represents the entire mandrel cylinder projected, but it is to be un derstood that the number and arrangement of such ports may be varied to suit structural requirements.

The upper group of ports 40 are positioned above the upper packer 5, and register permanently with similar-ports in the sleeve 34. There are preferably two ports in this group, spaced-180 degrees apart, and One such port 40 is shown in Fig. 2 and the other in Fig. 1. The center group is positioned between the upper packer 5 and the lower packer 6, and preferably comprises eight ports 41, arranged degrees apart in two inclined planes, as shown in Fig. 17, the ports of the two planes being in vertical alignment. The third. group is positioned below the lower packer 6, and preferably comprises seven ports 42, disposed similarly to and in vertical alignment with the ports 41. The fourth group is positioned at the lower end of the mandrel, below the third group,

and preferably comprises two ports 43 spaced 180 degrees apart and in the same horizontal plane.

The preferred arrangement of the valve tube ports is shown in dotted lines in Fig. 17. The upper group preferably comprises four ports 40 disposed in two horizontal planes corresponding with the planes of the mandrel ports 40, the two ports 40 in each 1 plane beingspaced 60 degrees apart, and the ports in the two planes being spaced respectively 180 degrees apart. The second group comprises eight ports 41, arranged in a manner similar to the mandrel ports 41. The third group comprises seven ports 42', likewise arranged similarly to the mandrel ports 42. The fourth group comprises two ports 43", spaced by 180 degrees in the same horizontal plane. This relative arrangement of the mandrel and valve ports'is such that the several desired combinations of open and closed ports occur at regular intervals of 60 degrees in the rotation of the valve tube 31, as will be further explained hereinafter. There are, therefore, six effective positions of the valve tube, which positions are located and determined, bythe operator at the surface of the ground, by the following mechanism.

[it the upper end of the mandrel 4 is a sleeve or ring 44, Fig.2, freely surrounding the valve tube 31, and prevented from rotating by inter-engaging tongues formed it on itself and said mandrel. The upper e ge of this ring 44, hereinafter called the stop ring, is formed with six notches, spaced degrees apart to correspond with the six effective positions of the valve tube 31. These six notches, which are designated consecutively as 46, 46*, 46, 46", 46, and 46 and clearly shown in the projection of the stop ring 44 in the upper portionof Fig. 17

are adapted to be engaged by a stop pin 47 carried by a sleeve 48, Figs. 2, 3 and 4. Said sleeve 48 is free to slide vertically on the valve tube 31, but is prevented from turning thereupon by feathers 49 preferablg formed integrally with said valve tube.

spring 50, interposed between the coupling sleeve 32 and said sleeve 48, keeps the stop pin 47 in engagement with the upper notched edge of the stop ring 44. The stop pin 47 is preferably formed separately from its holder sleeve 48, to permit its ready renewal in case of wear, and to this end is formed upon an arcuate block 51, Figs. 2, 15 and 16, with rounded edges 52, and adapted to be driven into a suitably formed notch in the holder sleeve 48. The top of said block 51 may be provided with a notch 53 to enable the ready insertion of a punch or other tool for a removing said block from its holder 48.

The stop pin 47, backed by its spring 50, therefore travels over the irregular surface of the stop ring 44 during the oscillation of the valve tube 31, the several effective positions of said valve tube being indicated to the operator by the amount of resistance ofi'ered to the turning of the tubing string to which said valve tube is attached by the engagement of said stop pin 47 with the various not ches of said stop ring 44. Two of these positions, corresponding with the notches 46? and 46, are located by positive stops formed by the vertical sides of a tongue 54, Fig. 17, formed between said

notches

46 and 46, and which prevents the stop pin 47 from traversing this portion of the ring. Thus the movement of the valve tube31 is restricted to an oscillation through an arc of 300 degrees. .The remaining positions of said valve tube are located by impositive or indicative stops formed by the engagement of the pin 47 with the

notches

46, 46, 46 and 46 and these are difierentiated from each other by the varying de-/ grees of resistance offered to the turning of the tubing string by the various shapes and depths of said notches. Thus in turning the valve tube to carry the pin 47 from the notch position 46 to 46", a constant but comparatively slight resistance is encountered, due to the inclination of the stop ring between these two notches. In moving away from the position 46", an initial strong resistance is felt, due to the relatively steep sides of the notch 46", which resistance is greater when moving toward the position 46 than 46. The notch 46 produces the same efiect as 46", but the directions are reversed. The notch 46 produces a relatively slight resistance in both directions. The position 46 maybe easily determined by its relation to the positions 46 and 46', the latter being a positive step. v

The lower end of the mandrel 4 is provided with a fluid director, comprising a sleeve 55, Figs. 1, 2, 7 and 8, which is fitted over said mandrel end and retained thereon by any suitable means, as for example, a set screw 56. An interior shoulder 57 serves to lock the mandrel plug 39 in position. Said sleeve 55is provided with an annular interior groove 58 near its upper end, which registers with and covers the mandrel ports 43 of the lowermost or fourth group described above. From this oove 58 are led passages 59, Fig. 8,-exten 'ng downwardly through the wall of the sleeve 55, and adapted to discharge the fluid issuing from the ports 43 in a downward direction.

The operation of the valve tube 31 in the control of the several groups of

mandrel ports

40, 41, 42 and 43 can best be understood by reference to the diagrams of Figs. 18 to 23 inclusive, wherein are shown the six efiective control positions of said valve tube referred to above. In the upper portion of all of these diagrams are shown projectionsof the stop ring 44, with the stop pin 47 in its six positions, and below are represented 'the mandrel 4 and the valve tube 31, indicating the open and closed ports at each such position of the stop pin. It is to be understood that these views are merely diagrams for indicating the effect on said ports of the movement of the valve tube, no attempt having been made to show the actual positions of said ports except in so far as such positions may relate to their proper functions. 7

In Fig. 18 the stop pin 47 is at the position 46 and all ports are closed. In Fig. 19 the stop pin 47 is in'the position 46", and only the intermediate group of ports 41, between the packers'5 and 6, are open. In Fig. 20 the stop pin 47 is in the position 46,

and only the lowermost, or fourth group of ports 43 are open, said ports discharging the fluid downwardly through the fluid director, not shown in Fig. 20. In Fig. 21 the stop pin 47 is in the position 46, and all ports are again closed. In Fig. 22 the stop pin. is in the position 46, and only the'uppermost group of ports 40, above the'upper packer 5,'are open. In Fig. 23 the stop pin 47 is in the position 46 and all ports except those of the second group, 41, are open, that is, the ports 40 above the upper packer 5, and the

ports

42 and 43, below the lower packer 6. are open.

In the operation of my improved perforation cleaner, the device is secured to the bottom of the tubing string and lowered into the well in the usual manner, the valve tube 31 being in the position shown in Fig. 23, to permit the fluid in the well to pass freely through the ports43 and 42, the valve tube 31 and the ports '40, and thereby to prevent interference with the downward movement of the device. -VVhen the perforated section of the casing 1 (shown only in Fig. 1) is reached, the valve tube is turned by means of the tubing strin 3, to the position shown in Fig. 18, in whlch all ports are closed. At this position the positive stop 54 prevents clockwise movement of the valve tube, so that if necessary, the screw 'oints of the tubing string may be tightened y turning said tubing string in a clockwise direction. Fluid under pressure, from any suitable source not shown in the drawings, 25-

is now supplied to the tubing string and valve-tube, and when such pressure builds up to the desired point as evidenced, for example, by a pressure gauge (not shown) connected'with the tubing string or supply conduit, thetubing string is turned in a counter-clockwise direction, until the first impositive stop is reached, and the pressure drops. The valve tube is now in the position shown in Fig. 19, the fluid being forcibly discharged through the ports 41 between the

packers

5 and 6, and consequently being forced out through the perforations of the casing situated between said packers.

' This clears said perforations and dislodges and loosens any caked formation that may adhere to the outside of the casing, the fluid passing up outside said casing and returning into it through the.perforations above the upper packer 5. By shifting the position of the cleaner and repeating this process in each new position, the entire perforated section of the casing can be cleaned.

If it is desired to clean the bottom of the well, as for example to loosen and remove caked formation such as the mud left in a new well from rotary drilling, the valve tube is first turned to the position shown in Fig. 21, in which all ports are closed. This osition can be easily determined, not only by the equal and constant resistance encountered when turning the tubing-string in either direction, but also by the fact that the pressure of the fluid therein rapidly builds up, all discharge ports being closed. A movement of 60 degrees in a clockwise direction, or until the first indicative stop is reached, brings the valve tube to the position of Fig. 20, opening only the lowermost group of ports 43, and discharging the fluid downwardly through the fluid director -notch 46*, while the absence of any shown in Figs. 1 and '2, thereby washing out the bottom of the well. A similar movement in the opposite direction from the position of Fig. 21 opens only the uppermost group of ports 40, as in Fig. 22,-discharging the fluid intothe casing above the upper packer 5. This position is useful for loosening any caked formation that may have settled above the cleaner and which might interfere with the pulling of the device from the well. It is also useful for introducing a column of fluid into the casing above the cleaner, to counteract, by its, weight or pressure, any gas or other fluid pressure below the cleaner, which might tend to force said cleaner and the tubing the pump or tubing string through the ports- 42 and 43. The pressure is equalized between the casing and the tubing string by the open upper ports 40, but by sealing the casing at the surface in the usual manner, the entire flow can be directed through the tubing string, thus eliminating wear on the casing due to sand carried in suspension in the oil. The device may also be used'as a packer at any desired depth in the well, the desiredfluid being admitted to the tubing string through either the upper or lower ports as circumstances may demand.

The preferred form of the stop ring 44, as shown in the drawings and described above, enables the operator to determine the various positions of the valve tube 31 with the greatest possible ease and accuracy. The most frequent movement of said valve tube is between the positions of Figs. 18 and 19, and in moving from the former to the latter position, there is a constant and relatively slight resistance to the turning force. The position of Fig. 19 is readily recognized by a sudden increase in this resistance, due to the engagement of the pin 47 with the pronounced notch at 46 prevents the valve tube from jumping ahead due to the resilience of the tubing string, and possibly passing the notch 46". The position of Fig. 18, and also that of Fig. 23, are easily determined by the positive stop 54. The next most frequently employed movements of the valve tube 31 are from the position of Fig. 21 to either that of Fig. 20 or Fig. 22; and in these cases the effects are the same as described above for the movement from the position of Fig. 18 to that of Fig. 19. The inclination of the surface of the stop ring 44 is suficient to hold the valve tube 51 in the positions of Figs. 18, 21 and 23, although permitting its ready movement away from these ositions.

My improved devlce 1S readlly accessible foracleaning and repair. The valve tube 31 and the entire stop mechanism can be replaced without removing any other parts.

ll claim J i 31.6 A well cleaner comprising a, chambered member adapted to be suspended within the well casing and having two spaced fluid discharge ports communicating withits interior, a packer carried by said member between said ports and adapted for closing the space between said member and the casing; means for selectively opening and closingeither" or both ports; and means for supplying fluid to the interior of said member.

2, A well cleaner comprising a chambered member adapted to be suspended within the well casing and having two spaced fluid discharge ports; a packer carried by said member between.said ports and adapted for closing the space between said member and the casing; a movable valve member for selectively opening and closing either or both and diflerentiating between the several port control positions of said valve member; and means for supplying fluid to said chambered member.

3. A cleaner for well casings comprising a chambered member adapted to be suspended within the well casing and having a plurality of spaced fluid discharge ports; spaced packers carried by said member for closing the space between it and the casing,

said packers separating said discharge ports into a plurality of groups; means for selectively opening and closing any groulp of discharge orts; and means for supp ying fluid to sald chambered member.

A. A cleaner for well casings comprising a chambered member adapted to be suspended within the well casing and having a plurality of spaced fluid dischargeports; spaced packers carried by said member for closing the space between it and the casing, said packers separating said discharge ports into a plurality of groups; a movable valve member for selectively opening and closing any group of discharge ports; means for indicating and differentiating between the several port control positions of Said valve orts; means for indicating a chambered member adapted to be suspended within a well casing and having two fluid discharge ports; a packer carried by said member for closing the space between it and the casing; a valve member adapted to be moved to aplurality of positions to open and close either or both ports; cooperating devices carried by said chambered member and said valve member for indicating the several port control positions of said valve member; and means for supplying fluid to said chambered member.

7. A cleaner for well casings comprising a chambered member adapted to be suspended vwithin a well casing and provided with a plurality of independently controllable fluid discharge ports; means for directing the fluid discharged from one of said ports in a downward direction; a packer carried by said member for closing the space heill?) tween it and the casing above the last mentioned port; and means for supplying fluid to said chambered member.

8. A cleaner for well casings comprising a chambered member adapted to be suspended within a well casing and provided with a plurality of independently controllable fluid discharge ports; a fluid director rem'ovably associated with the lower end of said member for directing the fluid discharged from one of said ports in a downward direction; a packer carried by said member for'closing the space between it and the casing; and means for supplying fluid to said chambered member.

9. A cleaner for well casings comprising a chambered member adapted to be suspended within a well casing and provided with a fluid discharge 'port; a valve associated with said member and adapted for oscillation to control said port; a packer carried by said llll member for closing the space between it and the well casing; means for supplying fluid to said member; and a movable dog carried by said member for enga ing the well casing to prevent said mem er from turning within said casing. 10. A cleaner for well casings comprising a chambered member adapted to be suspended within a well casing and provided with a fluid discharge port; a valve associated with pended within a well casing and provided with a fluid discharge port; a valve associated with said member and adapted for oscillation to control said port; means for supplying fluid to said member; a dog carried by said member and adapted for outward movement to engage the well casing to prevent said member from turning with n said casing; and a spring for pressing said dog into engagement with said casing; and

. means for limiting the outward movement of said dog.

12. A cleaner for perforated well casings comprising a chambered member adapted to be suspended within the well casing and provided with a fluid discharge port; a valve associated with. said member and adapted for oscillation to control said port; m ans for supplying fluid to saidmember; a movable dog carried by said member and adapted to engage the perforations of the casing to prevent said member from turning therewithin, the effective end of said dog being rounded in a vertical plane to cause it to disengage the perforations upon vertical movement of the member; means for resiliently pressing said dog outwardly into engagement with the perforations of said casing; and means for limiting the outward movement of said dog.

13. A cleaner for well casings comprising a hollow mandrel adapted to be suspended within the well casing and provided with a plurality of fluid discharge ports; means for supplying fluid to said mandrel; a movable valve member for selectively controlling said ports; positive stops adapted to be engaged by said valve member at the opposite limits of its movement; and an impositive stop adapted to be engaged by said valve member for indicating a port control position thereof between said positive stops.

14. A cleaner for well casings comprising a hollow mandrel adapted to be suspended within the well casing and provided with a plurality of fluid discharge ports; means for supplying fluid to said mandrel; a movable valve member for selectively controlling said ports; positive stops carried by said mandrel for limiting the movement of said valve member; an impositive stop carried by said mandrel for indicating a port control position of said valve member between said positive stops; and means carried by said valve member for engaging said positive and impositive stops.

15. A cleaner for well casiiws comprising a hollow mandrel adapted to be suspended within the well casing and provided with a plurality of fluid discharge ports; means for supplying fluid to said mandrel; a movable valve member for selectively controlling said ports; a member carried by said mandrel and provided with positive and impositive stops; and means carried by said valve member for engaging the stops of said mandrel member to indicate the several port control positions of said valve member.

16. A cleaner for well casings comprising a hollow mandrel adapted to be suspended within the well casing and provided with. a plurality of fluid discharge ports; means for supplying fluid to said mandrel; a movable valve member for selectively controlling said ports; a member carriedby said mandreland provided with a notched surface; and means carried by said valve member for engaging the notches of said mandrel member to indicate the several port control positions of said valve member.

17. A cleaner for well casings comprising a hollow mandrel adapted to be suspended within the well casing and provided with a plurality of fluid discharge ports; means for supplying fluid to said mandrel; a movable valve member for selectively controlling said ports, a member carried by said mandrel and provided with spaced projections and a notch therebetween; and means carried by said valve member for engaging said projectlons to l1m1t its movement and for engagmg said notch to lndlcate a port control position of said valve member between such larities of said ring to indicate the several port control positions of said valve memher. i

19. A cleaner for well casings comprising a hollow mandrel adapted to be suspended within the well casing and provided with a plurality of fluid discharge ports; a hollow valve member adapted for oscillation within said mandrel to selectively control said ports; means for supplying fluid to said valve member; a stop ring carried by said mandrel and providedwith an irregular surface; a lug projecting from said surface;

and a stop pin carried by said valve member and adapted to engage said lug'to limit the oscillation of said valve member and to engage the irregularities of said ring to indicate the port control positions of said valve member between such limits.

20. A cleaner for well casings comprising a hollow mandrel adapted to be suspended within the well casing and pro vided with a plurality of fluid discharge ports a hollow valve member adapted for oscillation within said mandrel to selectively control said ports; means for supplying fluid to said valve member; a ring carried by said mandrel and provided with an irregular surface; a second ring slid-ably mounted on said valve member for movement toward and away from the first ring; a stop pin carried by the second ring and adapted to travel over and engage the irregularities of the first ring to indicate the several port control positions of said valve member; and means for resiliently holding said stop pin in engagement with the irregular surface of the first ring.

21. In a device for the described purpose, a hollow mandrel provided with fluid discharge ports; a tubular valve member mounted for oscillation within said mandrel to control said ports, said valve member being adapted for connection with the tubing string of the well and having an exterior shoulder; and a sleeve associated with the mandrel and provided with an interior shoulder adapted to engage the exterior shoulder of said valve member to support the mandrel therefrom.

22. In a device of the described purpose, a

hollow mandrel provided with fluid discharge ports; a tubular valve member mounted for oscillation within said mandrel drel therefrom.

I 23. In a device for the described purpose, .a hollow mandrel provided with fluid discharge ports; a packer carried exteriorly upon said mandrel and adapted to close the spacebetween said mandrel and the well casing; a tubular valve member mounted for oscillation within said mandrel to control said ports, said valve member being adapted for connection with the tubing string of the well and having an exterior shoulder; a nut for retainin said packer in position upon said mandre and a sleeve carried by said nut and provided with an interior shoulder adapted to engage the exterior shoulder of'said valve member to support the mandrel therefrom.

2a. In a device for the described purpose, a

hollow mandrel provided with fluid discharge ports; a packer carried exteriorly upon said mandrel and adapted to close the space between said mandrel and the well casingga tubular valve member mounted for oscillation within said mandrel to control said ports, said valve member being adapted for connection with the tubing string of the well an exterior substantially horizontal groove adapted for engagement by a fishing tobl.

2-5. A. cleaner for well casings comprising a hollow mandrel having four fluiddischarge ports disposed throughout its length; upper and lower spaced packers carried by said mandrel for closing the space between it and the casing, there bein one port above the upper packer, one port 'etwe'en the two lpackers, and two ports below the lower packer; a valve member carried by said mandrel for selectively controlling said ports; and means for directing the discharge from the lowermost port in a downward direction. v 1

In testimony whereof I have signed my name to this specification,

ALUNZO IS HALLIDAYl