US2098494A - Apparatus for cleaning wells - Google Patents

Description

Nov. 9, 1937. J. GRANT APPARATUS FOR CLEANING WELLS 3 sheets-sheet 1 Filed July 20, 1935 m C f N VII Nov. 9, 1937. J. GRANT 2,098,494

APPARATUS FOR CLEANING WELLS Filed July 20, 1955 5 Sheets-Sheet 2 f \\\||I.Cf Il T, m m, @$0 n Nov. 9, 1937. J. GRANT 2,098,494

APPARATUS FOR CLEANING WELLS Filed July 20, 1935 3 Sheets-Sheet 3 Patented Nov. 9, 1937 UNITED STATES PATENT OFFICE 20 Claim!- This invention deals generally with apparatus which operates by the sudden release of-well pressureinto a low pressure or charge receiving chamber lowered into the well, to induce into said chamber a flow of well fluid carrying with it solid particles or bodies which it is desired to remove from the well or from the well pipe perforations. Apparatus oi this general type, and to all of which the invention is broadly applicable, includes suction-type fishing tools. bailers, and well cleaners for removing from the well screen perforations clogging particles, sand or other obstructing bodies.

The type of apparatus referred to abovevmay l5 lbe described generally as comprising a normally closed low pressure chamber contained within a tubular body portion of the apparatus or within the pipe on which the apparatus is suspended, and which is lowered, while closed, to the depth at which the operation is to be carried out. The low pressure chamber closure usually consists of a valve or member, such as a frangible disk. adapted to be opened or broken, as the case may be, to admit a charge of well fluid to the chamber.

The present invention relates particularly to apparatus of this type utilizing a frangible member as the charge receiving chamber closure.

Heretoiore, in such apparatus using a frangible member or disk as the closure, the closure opening means has consisted of a breaking member projected against the disk, or against which the disk is impacted. In spite of provisions made for bringing the disk and breaking member forcibly into engagement, it is frequently found that due to various conditions existing in the well, it is diillcult to break the disk. In fact, where the apparatus is not adapted to deliver repeated blows against the disk, it becomes necessary where the disk remains unbroken after one operation of the breaking member, to withdrawn the apparatus from the well, reset the disk breaking mechanism, and repeat the operation.

One of the primary objects of the invention is to provide a breaking means` for the frangible closure that will insure complete shattering of the latter in a single operation. The invention is characterized from past practice in that it utilizes an explosive for breaking the closure to place the charge receiving chamber into communication with the well. As will hereinafter appear, the invention is adaptable to various structural iorrns with respect to the particular way in which the explosive is used to rupture the disk. Preferably, the explosive is applied directly to the disk, and red by suitable means such as an electric current or by a firing pin projected against the explosive On the other hand if desired, the explosive may be located extraneous to the disk and utilized indirectly to supply the disk breaking force, by iiring a projectile against the disk.

'I'he above mentioned and various additional features and objects of the invention, as well as the details o! certain typical and illustrative' forms, will be more fully understood from the description to follow. Throughout the descrip- 1G tion reference is made to the accompanying drawings, in which:

Fig. 1-is a longitudinal section showing theupper portion of the well cleaning apparatus below the charge receiving chamber;

Fig. 2 is a downward continuation of Fig. r1 illustrating the lower portion of the apparatus;

Fig. 3 is a sectional view showing the body portion containing the charge receiving chamber;

Figs. 4 and 5 are sectional views similar to Figs. 2( 1 and 2, respectively, but showing the parts in changed position aiter the charge receiving chamber has been opened; A

Fig. 6 is an enlarged fragmentary section on line 6-6 of Fig. 1, showing the switch mechanism;

Figs. l and 8 are sections taken on lines 1--1 and 8-8 of Figs. 1 and 2, respectively;

Fig. 9 is a fragmentary section showing a variational form of disk breaking mechanism; and

Fig. 10 is a view similar to Fig. 9 showing a furv ther variant form of the invention.

As has been previously mentioned, the invention is particularly well adapted, but not limited, -3, to cleaning devices for dislodging foreign matter from the perforations of well casing. Accordingly, for the purpose of illustrating a typical embodiment oi the invention, I have shown in the accompanying drawings a perforation cleaner .4 positioned within a perforated casing or screen C having any suitable type of perforations, as here conventionally illustrated at P.

'I'he cleaner construction may be regarded generally as comprising relatively longitudinally 4 movable body and sleeve portions B and S, the lower portion of the body being in the form of a mandrel M extending through the sleeve S, as will hereinafter more fully appear. Threadably connected body or casing sections are indicated 5 at l0, Il and I2 (see Fig. 3), section Il serving as a head or top closure for the charge receiving or low pressure chamber lla. Coupling I3 is threadably connected to section I0 and serves as a means whereby the body may be attached 5 to a suspension element, for example cable I4. Section II, here shown as longitudinally contracted, may be or any desired length; and may be sectional. A 40 it. length gives the charge receiving chamber IIa a capacity ample for most operations.

Section III has a reduced axial bore I5 from which extends a transverse passage I6 controlled by a spring-closed, outwardly opening valve generally indicated at I1. The function of this valve is merely to 'relieve high pressure in the charge receiving chamber as the tool is raised into zones of lower pressure. To facilitate'unloading chamber Ila, after the latter has, received a charge and the cleaner is removed from the well, there is provided an inwardly opening, springclosed dump relief valve I3. This valve is fully described in the copending application of W. C. Erwin, et al., on Well bailers, Ser. No. 667,439, filed April 22, 1933, which has matured into Patent No. 2,059,629, granted Nov. 3, 1936. It will sulce here to state that screw plug I3 normally closes passageway 23. When chamber IIa is to be unloaded, plug I3 is removed and passageway 26 is then adapted to put the chamber into communication with the atmosphere when the lower pressure in the chamber (as created by dumping the uid) is of a value allowing springclosed valve I3 to open under atmospheric pressure.

Body section I2 has a reduced diameter bore 2I which may be considered as the inlet opening of chamber IIa, shoulder 22 at the upper end of bore 2I presenting an upwardly facing seat to take a foot valve 23. Section I2 is also provided with a removable dump door 24, the construction and mounting thereof being fully described in the copending application, Ser. No. 667,439. The door is opened by loosening screws 25 (which normally press the door inwardly to compress gasket 26 and provide a fluid-tight seal), rotating the door to clear lugs 21 from overhanging lips 23, and then sliding it transversely to clear it from way 23. It will be understood that the structure thus far described comprises no part of the present invention other than as it may be regarded as a typical and convenient type of low pressure chamber construction to which the present chamber opening mechanism may be applied. It is also to be understood that the expression normally closed low pressure chamber appearing in the claims,. is not intended to limit the invention to the use of a chamber that is closed at both its upper and lower ends, but rather to dene broadly a chamber that is at least closed at one end to normally exclude the well fluid.

Low pressure chamber II a normally is 4closed by a disk 33 clamped between the lower end of body section I2 and shoulder 3l within body section 32 threadedly connected at 33 with section I2. Disk 36 may be made of any suitable frangible material, such as glass or other ceramic composition, and may conveniently have a downwardly concave shape, as illustrated. It

will sumce to note at this point that disk 30 normally provides a fluid-tight bottom closure for the charge receiving chamber IIa, and that the cleaner is lowered in the well with chamber IIa empty. After the cleaner has been lowered to the depth of the well zone to be cleaned, the cleaning operation is then performed by breaking disk 36 to allow a sudden rush of well liquid through the casing perforations P and openings in sleeve S into the low pressure-chamber IIa,

as will later be more fully explained.

The lower end of section 32 is threadably connected at 35 with the reduced diameter lower tubular section 36 of the body, previously referred to as the mandrel portion M. The lower end of this mandrel section 36 is closed by a shoe 31, the bottom of which is tapered at 3l to facilitate passing any obstructions that might be encountered when the cleaner is being lowered. The sleeve structure S comprises a pair of longitudinally spaced packers, generally indicated at 39 and 40, which by engagement with the casing C, confine between them an annular space 4I through which suction is applied tothe casing perforations P opposite the space when the charge receiving chamber is opened, as hereinafter described. As typical, the packers 33 and 40 are shown each to comprise a cup leather or rubber 42 conned within a supporting annulus 43 clamped against shoulder 44 on the sleeve tube 45 by spacer sleeves 46, the latter in turn being held in place by nuts 41. The packers engage the casing with sumcient tightness to hold the sleeve assembly against substantial vertical movement in the casing during operation of the cleaner, as will later appear. Nuts 43 having rounded end surfaces 46a, are threaded on the upper and lower ends of tube 45.

As best illustrated in the cross section view of Fig. 8. opposite sides of the mandrel portion 36 of the body are flattened at 56 to form with sleeve 45, longitudinal by-pass passages 5I extending the full length of the sleeve. Between passages 5 I, the mandrel 36 has a fairly snug and substantially fluid-tight sliding ilt with sleeve 45. As best illustrated in Fig. '1. a pin 52 terminating in sleeve 45 extends through vertical slots 53 in the mandrel 36. Relative longitudinal movement between the body and sleeve assembly occurs within the limits of engagement of nut 43 on the upper end of sleeve 45 with the lower end of body portion 32, see Fig. 1. and the engagement of nut 48 on the bottom of the sleeve with the mandrel shoe 31. as shown in Fig. 5. During such relative longitudinal movement between the mandrel and sleeve, pin 52 travels vertically within slots 53.

The mandrel 36 is chamfered at 55 and 56 at both the upper and lower extremities of beveled surfaces 50 so that in the uppermost and lowermost positions of the, mandrel relative to the sleeve 48, the by-pass passages 5I will remain in open communication with the interior of the casing through the openings at 51 and 53, see Figs. l

and 5, formed by the chamfers 55 and 56. Op-

posite sides of the intermediate portion of sleeve 45 between packers 33 and 40 have longitudinal slots 60, see Fig. 2, the edges of which are beveled as indicated at 6I. Through these slots, suction is communicated to the surrounding space 4I between the packers by way of the mandrel bore 62 and a series of mandrel ports 63 registering with the sleeve slots 63. Some of the uppermost ports 63 may be in registration with slots 66 when the mandrel is in its uppermost position relative to the sleeve, see Figs. 1 and 2, but when the mandrel has been raised to its uppermost position, as shown in Figs. 4 and 5, all the ports 63 are brought into register with the slots 60. The

- illustrated construction embodied in the mandrel and sleeve assembly is more particularly and somewhat more extensively dealt with in a copending application, Ser. No. 22,297 filed May 20, 1935, by James J. Santiago on Well cleaning yievice (G), and reference may be had to this application for further details of this general type of well cleaner construction.

In the form of the invention illustrated in Fig. 1, the low pressure chamber closure 36 is opened to admit a well fluid charge by an explosive element ilred electrically under control of a suitable switch mechanism, the latter being operated by vertical movement of the suspension means |4. Here the disk 3 8 carries an explosive cap 66 which may be embedded in or otherwise carried directly by the disk itself. The cap is placed in an electric circuit comprising a conductor 61 grounded by contact with shoulder 3|, and an insulated wire 68 connecting with a switch device generally indicated at 69. Any suitable form of switch may be used, hence the type illustrated is to be regarded merely as typical. As shown in detail in Fig. 6, the switch 68 comprises an hermetically sealed body threaded at 1| into and supported by a spider 12 integral with the cleaner body section 32. The tubular switch body 10 contains one or more batteries 13 placed Within a liner 14 of suitable insulating material. The insulated conductor wire 68 connects with a terminal 15 against the lower end 15a of which the batteries are maintained in engagement by coil spring 16 supported on a metallic switch disk 11 placed on the upper insulated end 18 of rod 19. The latter is movable vertically within the body 10 and extends through a packing gland, conventionally illustrated at 80, which prevents the entry of well liquid to the interior of the switch cylinder. If desired, the tubular body 16 may contain a suitable non-conductive fluid. The terminal 15 extends through a bushing 82 of insulating material, and the connection between Wire 68 and the terminal 15 is insulated by a non-conductive material 84 contained within the upper interior of the body 10 above bushing 82.

A switch actuating mechanism, 'generally indicated at 86, operates to close the switch and thereby fire the explosive cap 66, by upward movement of the suspension means |4 and body B, and as a result of relative longitudinal movement between the body and theA sleeve S. The switch operating mechanism 86 comprises a rod 81 carrying on its lower end a looped stirrup 88 through which pin 52 extends. I'he rod and stirrup are supported on spider 89 by a coil spring 90 which normally holds the rod 81 in the elevated position of Fig. 1, in which position the rod engages and holds the switch rod 19 in raised position with the head 19a engaging the packing gland bushing 86a. Spring 96 thus is sufllciently strong to compress spring 16 and keep the switch open until rod 81 is pulled down to release rod 19 and allow the contact disk 11 to be moved down, under the influence of spring 16, into engagement with shoulder 10a to close the circuit. Although spring 16 is weaker than spring 96, the former will be sufficiently strong to` overcome the frictional resistance to downward movement of rod 19 offered by the packing gland 80.

In operation, the body B and sleeve S assembly is inserted within the casing C with the upper portion of the body above section 32, removed. When inserted in the casing, the mandrel M and sleeve S will have the relative position shown in Figs. l and 2, with rod 81 engaging the head 19a I taining the low pressure chamber and comprising sections I6, and I2, is next threaded into the upper end of section 32 and the joint at 33 taken up to clamp the disk 30 in place. The apparatus is then lowered in the well to the depth of the zone to be cleaned, the packers 39 and 40 offering suflicient resistance to downward movement of the sleeve S to maintain the partsin the relative positions of Figs. 1 and 2.

Pin 52 and the stirrup 88 provide a lost motion connection between the sleeve S and rod 81 in order that if i'or any reason the sleeve should tend to drop relative to the mandrel M while the apparatus is being lowered, the cap 66 will not become prematurely fired to open the low pressure chamber, before the tool is in proper position for the cleaning operation. Thus, by virtue of this lost motion connection, sleeve S is capable of downward movement from the position of Figs. 1 and 2 a distance corresponding to the distance between pin 52 and the lower end oi.' stirrup'88, before rod 81 is pulled down.

When the apparatus has been lowered to'the proper depth, cap 66 is fired to break the disk 30 and open the low pressure chamber by upward movement of the suspension means I A and elevation oi' the body B. As the body moves upward relative to the sleeve, the lower end of stirrup 88 is brought into engagement with pin 52, whereupon rod 81 is held against further upward movement. Since rod 19 is maintained in engagement with the upper end of rod 81 by the action of spring 16, continued elevation of the body causes shoulder 10a to be raised into contact with disk 11. This contact completes the electric circuit, exploding the cap 66 and breaking disk 36, with the result that the low pressure chamber ||a is suddenly placed in communication with the body passage 92 and mandrel bore 62. Further upward movement of the body brings the lower Iend of the mandrel into engagement with the bottom of sleeve S and the parts into the relative positions of Figs. 4 and 5.

The mandrel ports 63 have thus been brought into registration with slots 60 in the sleeve, and byreason of the pressure differential between the formation pressure at the outside of the casing, and the pressure in the charge receiving chamber l'la, there is induced a sudden ilow of well fluid through the casing perforationsI P into space 4| between the packers, and thence through ports 63 into the mandrel bore 62. The well liquid charge flows upwardly through passage 82, bore 2|, past foot valve 23 into chamber a, and continues to flow into the low pressure chamber until a substantial pressure balance exists. whereupon valve4 23 seats to trap the charge in the chamber. The apparatus then is removed from the well, and the door 24 removed to dump the charge.

In addition to providing a means for insuring sudden and complete opening of the charge receiving chamber, the explosion of element 66 has a further advantage in that the combination of the explosive force, followed by the sudden suction effect upon opening the low pressure chamber, is of particular effectiveness in dislodging clogging particles from the casing perforations. When the cap explodes, the expansive force produces a sudden downward surge of fluid within the body, out through ports 63 into space 4|, and through the casing perforations, the eect of which is to loosen and displace the clogging particles outwardly in the direction of the fluid surge. However, this surge is immediately followed by an equally sudden surge in the opposite direction due to the effect of the low pressure chamber being put into communication with space 4|. with the result that the clogging particles, immediately after they are loosened by the outward fluid surge, are drawn into the perforations by the oppositely acting impulse.

Fig. 9 shows a variational i'orm of the invention similar in all respects to the previously described form except as to the means for ilring the explosive cap. Here the disk 30a carries an explosive cap 95 which is exploded by a spring loaded iiring mechanism, generally indicated at Il, actuated as a result of upward movement of the body B relative to the previously described sleeve assembly. Stirrup carrying rod 01', corresponding to rod 01 in the first described form, normally is supported in a position corresponding to that of Fig. l, by coil spring 91 seating on spider 90 and bearing against a tubular latch 99 attached to the upper end of the rod. Latch I operates to releasably engage and cock the ilring pin |00 which is supported by spring |0| on spider |02.

Upon upward movement of the body B, the parts remain in the positions shown in Fig. 9 until the lower end of stirrup 08 (referred to in Fig. 1) engages pin 02, whereupon continued upward movement of the body brings the `spring iinger detents 99a of latch 99 into engagement with the end enlargement |03 of the ring pin, holding the latter against upward movement and compressing spring 0|. After spring |0| is compressed and the iiring pin cocked, further upward movement of the body releases the enlargement |00 from the latch, causing the firing pin to be projected against the cap 95 to explode the disk and open the low pressure chamber through inlet 2| into communication with the casing perforations, all in the manner previously explained.

Fig. l0 shows a second variational form of the invention in which the disk is broken by a projectile nred by an explosive extraneous to the disk, as distinguished from the previously described forms in which the explosive is carried directly by the disk. Here the projectile |05 inserted within barrel |00 threaded into the upper end of spider I 01, is fired by an explosive cap |08 which is exploded by a iiring mechanism |09 generally similar to the ilring mechanism of Fig. 9. Upon upward movement of the body B, latch 99 engages the enlargement |03 on the ring pin |00', causing spring ||0 to be compressed to cock the ilring pin. When released by the latch 99', the ilring pin is projected against the cap |09 and the projectile |05 ired against the disk to break it and open the low pressure chamber.

I claim:

1. In oil well apparatus of the character described, means iorming a normally closed low pressure chamber, said means including a wall containing a well fluid inlet opening, an inlet closure applied directly to said wall and across said opening, and explosive means adapted to be tired to open said closure for the entry of a well iluid charge to the chamber.

2. In oil well apparatus of the character described, means !orming a low pressure chamber, said means including a wall containing a normally closed inlet passage extending therethrough, explosive means adapted to be ilred to open said passage for the entry of a well iluid charge to the chamber, and means for firing said explosive means. s

3. In oil well apparatus of the character described, walls forming a normally closed low pressure chamber, explosive means adapted to be red to open said chamber for the entry of a well fluid charge, and means normally contained in the apparatus and operating automatically to trap said charge in the low pressure chamber.

4. In oil well apparatus of the character described, means forming a normally closed low pressure chamber, said means including a wall at the lower end of said chamber and containing a normally closed, vertically extending inlet passage extending therethrough, explosive means adapted to be fired to open said passage for the entry of a well iluid charge to the chamber, and passage means for ilring said explosive means.

5. In oil well apparatus of the character described, means forming a normally closed low pressure chamber, explosive means adapted to be ilred to open said chamber for entry of a well fluid charge, and spring actuated means for iiring said explosive means.

6. In oil well apparatus of the character described, a body including means forming a normally closed low pressure chamber, a cable suspending said body in the well, a closure adapted to be opened to admit a well fluid charge to said chamber, and explosive means adapted to be red to open said closure.

v'1. In oil well apparatus of the character described, walls forming a normally closed low pressure chamber and containing a well fluid inlet, a frangible closure inserted in said inlet and adapted to be opened to admit a well fluid charge to said chamber, and explosive means adapted to be fired to break said closure.

8. In oil well apparatus of the character described, means forming a normally closed low pressure chamber, a closure adapted to be opened to admit a well fluid charge to said chamber, and explosive means adapted to be red to open said closure, the last mentioned means comprising an explosive carried by said closure.

9. In oil well apparatus of the character described, means forming a normally closed low pressure chamber, a closure adapted to be opened to admit a well fluid charge to said chamber, an explosive carried by said closure, and electrically operated means for tiring said explosive to open the closure.

10. In oil well apparatus of the character described, means iorming a normally closed low pressure chamber, a closure adapted to be opened to admit a well iluid charge to said chamber, an explosive carried by said closure, and means adapted to be projected against said explosive to cause it to ilre and open said closure.

11. In oil well apparatus oi the character described, means forming a normally closed. low pressure chamber, a suspension means on which the apparatus is lowered in the well, explosive means adapted to be ilred to open said chamber for the entry of a well iluid charge, and means operable by movement of said suspension means to tire said explosive means.

12. In oil well apparatus oi' the character described, means forming a normally closed low pressure chamber, a. suspension means on which the apparatus is lowered in the well, explosive means adapted to be .red to open said chamber forthe entry of a well uid charge, and means operable by upward movement of said suspension means to re said explosive means.

13. In well cleaning apparatus adapted to be lowered within a perforated section of well tubing, an apertured tubular member adapted to be lowered within said perforated well tubing, a pair of spaced tubing engaging packers carried by said member beyond its apertured portion, ex-

plosive means within the apparatus and adapted to be nred to dislodge clogging particles from the tubing perforations by creating a sudden outward ow of iiuid through the aperture of said member and through said perforations, and means for ring said explosive means.

14. In well cleaning apparatus of the character described, a body forming a normally closed low pressure chamber, an apertured tubular member extending below the body and adapted to be lowered within a perforated section of well tubing, the interior of said tubular member being communicable with said chamber, a tubing engaging packer carried by said member, and explosive means within the apparatus adapted to be fired to open said low pressure chamber for the entry of well fluid through said perforations and apertured member into the chamber.

15. In well cleaning apparatus of the character described, a body forming a normally closed low pressure chamber, an apertured tubular member extending below the body and adapted to be lowered within a perforated section of well tubing, the interior of said tubular member being communicable with said chamber, a tubing engaging packer carried by said member, a frangible closure for said chamber at the lower end of said body, and explosive means within the apparatus for breaking said closure.

16. In well cleaning apparatus of the character described, a body forming a normally closed low pressure chamber, a relatively vertically movable apertured tubular member extending below the body and adapted to be lowered within a perforated section of well tubing, the interior of said tubular member being communicable with said chamber, a tubing engaging packer carried by said member, and explosive means within the apparatus adapted to be fired by virtue of relative vertical movement between said body and tubular member to open said low pressure chamber for the entry of well fluid through said perforations and apertured member into the chamber.

17. In well cleaning apparatus of the character described, a body forming a normally closed low pressure chamber, a relatively vertically movable apertured tubular member extending below the body and adapted to be lowered Within a perforated section of well tubing, the interior of said tubular member being communicable with said chamber, a tubing engaging packer carried by said member, a frangible closure for said chamber, explosive means within the apparatus for breaking said closure, and means operable by relative movement between said body and tubular member to ilre said explosive means.

18. In well cleaning apparatus adapted to be lowered within a perforated section of well tubing, a body containing means operable to dislodge clogging particles from the tubing perforations by creating a sudden outward ilow of fluid therethrough, a cable suspending said body in the well, and means for communicating to the inside of said pe'rforated section of tubing an abnormally low pressure to induce a sudden inward flow of fluid through said perforations immediately after the operation of the rst mentioned means, the last mentioned means being controllable by movement of said cable.

19. In well cleaning apparatus adapted to be lowered within a perforated section of well tubing, a suspension means on which the apparatus slowered in the well, means operable by movement of the suspension means to dislodge clogging particles from the tubing perforations by creating a sudden outward flow of uid therethrough, means for communicating to the inside of said perforated section of tubing an abnormally. low pressure to induce a sudden inward flow of fluid through said perforations immediately after the operation of the first mentioned means, and means confining the communication of said abnormally low pressure to a portion only of the tubing perforations.

20. In well cleaning apparatus adapted to be lowered within a perforated section of well tubing, a tubular member having normally open apertures adapted to be exposed directly to the casing perforations, means operable to dislodge clogging particles from the tubing perforations by creating a sudden outward now -of uid through said apertures and perforations, means for communicating to the inside of said perforated section of tubing an abnormally low pressure to induce a sudden inward flow of fluid through said perforations immediately after the operation of the ilrst mentioned means, means confining the communication of said abnormally low pressure to a portion only of the tubing perforations, and means for trapping the uid drawn inwardly through said perforations, for removal to the ground surface.

JOHN GRANT.

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