US3614988A

US3614988A - Differential pressure tools for plugging holes in well pipe

Info

Publication number: US3614988A
Authority: US
Inventors: Lawrence K Moore
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-07-30
Filing date: 1969-07-30
Publication date: 1971-10-26
Anticipated expiration: 1988-10-26

Abstract

APPARATUS OR TOOLS FOR PLUGGING OR CLOSING HOLES, CRACKS, OR OTHER OPENINGS IN A CASING OR OTHER WELL PIPE, WHEREIN FLUID FLOW THROUGH THE HOLE CAUSED BY A DIFFERENTIAL FLUID PRESSURE BETWEEN THE INSIDE AND THE OUTSIDE OF THE PIPE IS UTILIZED FOR SEATING THE APPARATUS OVER THE OPENING, AND FOR INTRODUCING CLOSURE MATERIAL THROUGH THE OPENING FOR FORMING A PLUG OR CLOSURE THEREFOR.

Description

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Oct. 26, 1971 L.. K. MooRE 3,614,988

DIFFERENTIAL PRESSURE TOOLS FOR PLUGGING HOLES IN WELL PIPE Filed July'so, `1969 4 sheets-sheet 1 TTORNE YS oct. 26, `1971 K, MOORE 3,614,988

DIFFERENTIAL PRESSURE TOOLS FOR PLUGGING HOLES IN WFLL P'II'IEZ Filed July 50, 1969 4 Sl1eets-Shoot :r

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pmwef & Mafflw TTORNE YS L. K. MOORE Oct. 26, 1971 DIFFERENTIAL PRESSURE TooLsEoE PLUGGING HOLES IN WELL PIPE 4 Sheets-Sheet .'5

Filed July 50, 1969 n '..Illr.

Zan/fvr@ /f Mao/e ATTORNEYS Oct. 26, 1,971 L. K. MOORE 3,614,988

DIFFERENTIAL PRESSURE TOOLS FOR PLUGGING HOLES N WELL PIPE Filed July 30, 1969 4 SheetsSheot 4l OOQOO ,/5/25 OGOOO l00000 OOGOO b/-5/2 0OOO0 ogOOo 00000 0 O00 00000 O000 (0o O0 00 U 0W/@06e ff. Moa/e i INI/ENTOR nvm/ef f MaNLeu/A TTORNE YS United States Patent O 3,614,988 DIFFERENTIAL PRESSURE TOOLS FOR PLUGGING HOLES IN WELL PIPE Lawrence K. Moore, 3716 Ingold, Houston, Tex.

Filed July 30, 1969, Ser. No. 846,203 Int. Cl. E21b 33/13 U.S. Cl. 166-193 15 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION The eld of this invention is apparatus for sealing or patching holes or other openings in casing or well plpe.

There are many situations in which holes, cracks or other openings occur either intentionally or accidentally, in well casing or other well pipe. For example, the hole may occur because of an intentional perforation usmg conventional perforating apparatus, or the hole, crack or other opening may occur because of corrosion, a defect in the pipe or an unintentional puncturing of the pipe.

In the past, such openings in casing or well pipe have sometimes been patched with metal liners, such as lllustrated in U..S. Pats. Nos. 3,167,122 and 3,191,677, but so far as is known, none have employed a sealing material in liquid or semi-solid form which later solidiiies to effect a seal or closure. Apparatus has been developed which rst perforates and then injects fluids through the perforations such asshown in U.S. Pats. Nos. 2,457,277 and 2,526,695, but none of such patents disclose the sealing of a hole in a pipe wherein a uid pressure dierential is used for the seating of the apparatus in the hole.

SUMMARY OF THE INVENTION This invention relates to apparatus for sealing or closing a hole, crack or other opening in a well casing or pipe. With such apparatus, a fluid pressure dilerential between the inside and the outside of the pipe to be sealed is utilized for locating a part of the apparatus in contact with the well pipe adjacent to the opening, and closure material is introduced through the opening for forming a plug or closure therefor.

BRIEF DESCRIPTION OF THE DRAWING FIG. l is a vertical sectional View, partly in elevation, of one form of the apparatus of this invention, illustrated in position in a well pipe or casing in proximity to a hole to be plugged or sealed using the apparatus of this invention;

FIG. 2 is a View similar to FIG. 1, but illustrating the apparatus with the hole in well pipe or casing plugged or closed;

FIG. 3 is a bottom view of the apparatus illustrated -in FIG. 1;

FIG. 4 is an enlarged sectional view illustrating a portion of the apparatus of FIG. l in position in a hole in a well casing or pipe;

FIG. 5 is a vertical sectional view, partly in elevation, illustrating a modied form of the apparatus of this invention;

FIG. 6 is a sectional view of the apparatus of FIG. 5, taken on line 6 6 of FIG. 5;

FIG. 7 is a vertical sectional view, partly in elevation,

ACC

illustrating a further modification of the apparatus of this invention;

FIG. 8 is a vertical sectional view, partly in elevation, illustrating still another modification of the apparatus of this invention in the position it assumes during the lowering of same into a well pipe or casing;

FIG. 9 is a view similar to FIG. 8, but illustrating such apparatus in position -in a hole in a well pipe or casing;

FIG. 10 is a vertical sectional View of another form of the invention, illustrating the apparatus in a position during the lowering or dropping of same in a well pipe or casing;

FIG. 11 is a view of the apparatus of FIG. 10 after the apparatus has moved into sealing position in a hole in a well pipe or casing;

FIG. 12 is -a vertical sectional view, partly in elevation, illustrating another form of the invention in position adjacent an opening in a pipe or casing to be plugged or closed;

FIG. 13 is a side view of a portion of the apparatus of FIG. 12 illustrating the surface of the pipe engaging element adapted to be positioned adjacent the opening in the pipe which is to be plugged or closed;

FIG. 14 is a View similar to FIG. 13, but illustrating the pipe engaging element of FIG. 12 in a different shape from that of FIG. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, the letter A designates generally one form of the apparatus of this invention which is particularly illustrated Iin FIGS. 1-4. The apparatus A includes a receptacle 10 for holding a sealing material S. The receptacle 10 is in iluid communication with a mixing chamber 11 which forms a passageway through a pipe engaging element 12 having a sealing surface 12a for sealing engagement with the -inside of the well pipe P surrounding an opening H. A ilexible head 15 is mounted outwardly of the pipe engaging element 12 and such head 15 is adapted to be deformed or flexed enough to pass through a hole or other opening H in the well pipe or casing P. Briefly, the receptacle 10 is provided with means such as pistons 20 which are adapted to be actuated by fluid pressure or other suitable pressure to force the sealing material S from the receptacle 10 and outwardly therefrom through suitable outlets 15a in each flexible head 15 for depositing the sealing material S externally of the pipe P adjacent the hole H (FIG. 2) to thereby provide a closure or seal upon the hardening or solidifying of same to prevent further ow of uids through the hole H.

Considering the invention more in detail, the apparatus A may -be lowered into the casing or well pipe P on a conventional wire line 21 or cable or any other suitable support. As illustrated in FIG. 1, the wire line or other support 21 is connected to a cap 22 which is threaded at 22a or is otherwise connected to the upper end of the receptacle 10. One or more openings 22h are provided in the cap 22 for establishing communication between the exterior of the receptacle 10 and the area at the upper end of such receptacle 10.

The receptacle 10 is preferably divided into two compartments 10a and 10b by means of a central separator or partition 10c so that when the sealing material S is formed of two or more components, the components may be kept separated from each other until it is desired to mix same and inject them into the hole H. Each of the compartments 10a and 10b has a piston 20 disposed therein with an annular seal ring 20a formed of rubber or other suitable sealing material therewith.

'Each of the chambers 10a and 10b has an outlet or dis charge opening 10d which establishes communication from the compartments 10a and 10b to the mixing chamber 11 therebelow. The passages d are temporarily closed by disks 23 which are made of relatively thin aluminum, plastic, or any other material which is capable of being ruptured or punctured `by the application of pressure thereto when the piston 20 moves downwardly in the receptacle 10, as will be more evident hereafter. The disks 23 thus keep the two compartments 10a and 10b isolated from each other so as to maintain the components of sealing material S therein separated from each other until it is time to mix same together for injection into the holes H. By way of example, the sealing material S may be an epoxy resin and therefore each of the common components thereof are kept separated in the two compartments 10a and 10b so as to maintain same in a liquid form until it is desired to inject them into the hole H where they become solidified due to their mixing and chemical reaction.

In the form of the invention illustrated in FIGS. 1 4, there are a plurality of the flexible heads (FIG. 3), the number of which may vary. In some instances, only a single flexible head 15 is employed, but usually, a plurality of such flexible heads 15 are employed since it facilitates the movement of one of the heads 15 into the hole H to be plugged, as will be more evident hereafter.

Each of the flexible heads 15 is preferably constructed as illustrated in detail in FIG. 4. The flexible head 15 may be formed of rubber or a flexible plastic such as polyethylene or any other suitable material which is capable of being deformed sufficiently to pass through the hole H. It is to be noted that the flexible head 15 is substantially conical, but it has a rounded nose 15b and the diameter of the rounded nose 15 is smaller than the diameter of the hole H into which such head 15 is intended to be inserted. On the other hand, the base 15e of the head 15 is of a greater diameter than the diameter of the hole H so that the flexible head 15 must be compressed or squeezed down to a smaller diameter to enable the base 15e and the other parts of a larger diameter than the hole H to pass through the hole H in moving from the position shown in FIG. l to that shown in FIGS. 2 and 4. Therefore, when the head 15 reaches the position shown in FIGS. 2 and 4, the base 15e` re-extends itself due to the flexibility of the material of the head 15 so that the base 15e prevents or resists a return or withdrawal of the head 15 through the hole H. The space between the base 15e and the inner surface 12a of the pipe engaging element 12 is substantially equal to the thickness of the pipe P in the vicinity of the hole H so that when the head 15 has passed through the hole H, the apparatus is essentially locked in position adjacent the hole H as shown in FIGS. 2 and 4.

A one-way check valve 25 which is urged to a closed position by a spring 25a serves to permit the discharge of the sealing material S from the mixing chamber 11 through a port 11a into the interior 15d of the head 15, but it prevents the flow of fluid inwardly from the interior 15d of the head 15 into the mixing chamber 11. The sealing material is discharged for the interior 15d of the head 15 through an outlet opening or openings 15a in the base 15e of the head 15 so that such sealing material is deposited in the hole H and externally of the pipe P to form a mass around the element or head 15 and over the hole H so that upon the hardening or solidifying of the material S, a plug or seal is provided for the hole H.

To equalize the pressure acting upon the upper and lower ends of the compartments 10a and 10b and therefore, the sealing material S therein, a flexible equalizing bag 26 is secured below the mixing chamber 11 and is in communication therewith through a port 11b. Thus, when the apparatus A is lowered into a well pipe P having a fluid therein, the pressure acting on the pistons will increase at the increasing depth of the liquid in the pipe P. Essentially the same pressure will also be acting upon the flexible bag 26, whereby there is an equalization of pressure on the sealing material S during the lowering 4 and/or raising of the apparatus A in the fluid within the well pipe P.

In the operation or use of the apparatus A of this invention, the apparatus A is lowered in the well pipe P on the wire line 21 or other suitable support. The approximate depth of the hole H is known in advance so that the apparatus A is first lowered to a point in proximity to such elevation and is preferably lowered below the hole H. During the lowering of the apparatus or tool A, fluid, such as Water or drilling fluid, is pumped from a conventional pump downwardly through the well pipe P and outwardly through the hole H to the area externally of the pipe P. A fluid pressure differential thus exists or is created between the interior of the pipe P and the area externally thereof, the extent of which depends upon the pumping pressure and well fluid conditions. It is also possible to use a gas instead of a liquid for creating such differential pressure, and as used herein, the term fluid includes either a liquid or a gas for such operation. The operator notes the reading on the fluid pressure gauge at the surface during the lowering of the apparatus A so that he can compare it with subsequent readings, as will be explained.

The apparatus or tool A is moved downwardly to a point below the hole H and then is moved slowly upwardly to a point above the hole H until one of the flexible heads 15 comes close enough to the hole H to be forced therethrough by the fluid being pumped through the hole H. Since the pressure internally of the pipe P is greater than the pressure externally thereof, the fluid is flowing outwardly through the hole H at a relatively high velocity, so that the fluid velocity acts to force the element 12 towards the hole H to cause the surface 12a to seat around the hole H and close off all or substantially all fluid flow through the hole H. It is to be noted that the sealing surface 12a preferably conforms to the curvature of the inside wall of the pipe P (FIG. 3). The closest head 15 to the hole H is also caused to move towards same and once the head 15 is in engagement with the hole H, the differential in pressure then acts against the pipe engaging element 12 and the other substantially vertically extending surfaces to force the head 15 through the hole H.

If only one of the heads 15 is employed on the apparatus A, the apparatus A may have to be turned or rotated as it is being raised and lowered to position the head 15 close enough to the hole H to enable the flowing liquid to force same through the hole H. However, where there are a plurality of such heads 15 as shown in FIGS. 1, 2 and 4, the chances of one of such heads 15 entering the hole H are increased sufficiently so that very little movement in a rotational direction, if any, is required from the surface.

When the member 15 has been forced through the hole H to the position shown in FIGS. 2 and 4, the operator at the surface will know that this has occurred in two ways. First, the weight indicator on the wire line 21 will show a change in the weight reading, the extent of which will depend upon whether the tool was being raised or lowered when a head 15 was forced through the hole H. Also, the pressure gauge for the fluid being circulated inside of the pipe P will show an immediate increase in pressure since the flow of the fluid through the hole H has been cut off or substantially cut off by the contact of the pipe engaging element 12 with the inside surface of the pipe P. In any event, when one or both of the above indicators are noted by the operator, the movement of the wire line 21 by the operator is stopped and the pressure is allowed to reach a predetermined amount as indicated by the pressure gauge.

In the form of the invention illustrated in FIG. 1, the fluid Within the pipe P then serves to force the sealing material S outwardly from the receptacle 10 through the single head 15 which has been inserted into the hole H. The sealing material S is forced downwardly by the pistons 20 which are forced downwardly by the fluid pressure acting thereon so as to initially rupture the disks 23. The sealing material S then flows through the passages d into the mixing chamber 11 where it is mixed together. It should be noted that the mixing chamber 11 is preferably initially lled with a liquid such as a cleaning fluid or acid, and the bag 26 is preferably filled with the same liquid. The bag 26 collapses (FIG. 2) when the head 15 enters the hole H since the pressure internally of the pipe P is greater than that externally of the pipe P. The cleaning liquid or acid is forced out through the ports or outlets 15a of the single head 15 which is positioned through the hole H as the sealing material S is forced downwardly into the mixing chamber 11. The cleaning agent or acid tends to clean the area around the head 15 in the hole H in advance of the distribution of the sealing material S around such head 15 to thereby provide a clean area for the epoxy resin or other sealing material to accumulate for subsequent hardening, It should be noted that the heads 15 which do not go through the hole H remain closed as the sealing material S is forced outwardly through the head 15 which is in the hole H because those heads 15 which are still in the pipe P are subjected to the same pressure externally thereof as the pressure being exerted on the sealing material S. Since the pressure internally and externally of such heads 15 in the pipe P is thus substantially the same, the spring 25a in conjunction with each of the ball valves 25 for such heads 15 keeps the ball valves 25 closed. However, as to the head 15 which has been inserted into the hole H, the spring 25a is not sufllciently strong to prevent the sealing material S from forcing the ball 25 against the spring 25a and then forcing the sealing material S outwardly through the outlets 15a.

The tool A is left in position a sufficient time to permit the sealing material S to harden or solidify into a mass forming a seal or plug such as illustrated in FIG. 2. The particular length of the time required will depend upon the type of resin or other material employed.

After the sealing material S has solidified, the apparatus A may be released from the head 15 and its pipe engaging element 12 which are disposed in the hole or adjacent to the hole H. To effect such release, the wire line 21 is manipulated, using conventional jars, weights, or other means in any known manner for applying a severing force to the tube 11C of the mixing chamber 11. The external surface of the tube 11e` may be scored or otherwise provided with a break point to facilitate the breaking of same at a particular spot inwardly of the element 12. During the manipulation of the wire line 21, or the other action thereon for effecting a shearing of the tool A from the part which is in the hole H, it is preferable to leave or maintain the pressure of the fluid within the pipe P to facilitate the holding of the element 12 and the parts outwardly therefrom in the hole H, or adjacent to such hole H. After the tool A has been retrieved, it may be repaired or the parts replaced by any suitable means for a subsequent operation using the same tool A.

The operator will know at the surface of the well that the sealing material S has properly and completely plugged the hole H because the pressure of the fluid within the pipe P will remain the same. If the hole H has not been properly plugged, the pressure of the fluid in the pipe P will gradually drop off. The pressure of the fluid within the pipe P may either be released or maintained while the tool is being retrieved to the surface.

The effectiveness of the closure or seal S may also be tested from externally of the pipe P by developing a pressure externally of the pipe P which is greater than the hydrostatic pressure within the pipe P, and such testing can be effected in any known manner.

In FIG. 5, a modified apparatus A-1 is illustrated wherein the parts which are similar to those of FIG. l have the same letters and/or numerals. The receptacle 110 of the apparatus A-1 is formed with a flexible wall or cylinder of rubber, plastic or other similar material.

The cap 122 is preferably the same as the cap 22 Of FIG. 1 except that it does not have the openings 22b. The cap 122 is preferably connected to a closure plate 112a which is threaded thereto and which has the upper end of the receptacle secured thereto by a wire 30 or other suitable attaching means. A partition 110C extends downwardly from and is preferably integral with the closure 122e so as to divide the receptacle 110 into compartments l10n and 110b. Also, a perforated cylinder Or tube 31 having openings 31a spaced longitudinally throughout its length is disposed near the center of the receptacle 110 (FIG. 6), and such tube or cylinder 31 is preferably also secured or is formed integrally with plate 122a.

The lower end of the receptacle 110 is preferably formed with a lower section 110e which has a single port 110d in communication with the area inside of the tube 31, on both sides of the separator plate 110C. The section 110e is preferably formed integrally with the tubes 11C forming the walls for the mixing chamber 11 and leading to each of the pipe engaging elements 12 and the flexible heads 15. The flexible bag 26 is disposed below the mixing chamber 11 in the same manner as described heretofore in connection with 21.

Semi-circular sealing disks 123 are disposed on each side of the separator plate 110e near the bottom of the tube 31 for maintaining the sealing material S separated from cleaning fluid or acid within the mixing chamber 11, passage 110d, and the flexible bag 26, until such disks 123 are ruptured.

The operation or use of the form of the invention A-1 illustrated in FIGS. 5 and 6 is substantially the same as that illustrated in FIG. 1 4 except that the sealing material S is forced outwardly from the receptacle 110 by the collapsing of the wall of the receptacle 110 to force the contents thereof through the opening 31a and then downwardly into the mixing chamber 11 and outwardly through the flexible head 15 which has been forced into a hole such as a hole H illustrated in FIG. 2. The ports 31a permit the sealing material S which is in liquid form to move therethrough, but since the tube 31 is spaced from the separator plate 110e as thus seen in FIG. 6, the collapsing of the wall of the receptacle 110` cannot result in cutting off the discharge of substantially all of the contents of the receptacle 110 through the discharge opening 110b. When the sealing material S is an epoxy resin which has its two components separated, each of the components will be in one of the

compartments

110a or 110b, but it will be appreciated that if the material S is a liquid or a semi-liquid material which is a single component and which sets by dehydration or other means after being discharged from the apparatus A-1, it is not necessary to include the separator 110e or the disks 123. The tube 31 might also be eliminated in such instance.

In FIG. 7, another form A-2 of the apparatus is illustrated wherein the receptacle 210 has a single compartment with the sealing material S being a single component material. For example, the sealing material S may be an expandable cement slurry, a silicone rubber, or any other material which is in a liquid or a substantially liquid form in the receptacle 210 and which solidifies after being discharged through the flexible head 15 by dehydration, drying, or curing externally of the pipe P. It will be appreciated that the single component sealing material S may be used in the other forms of apparatus illustrated in this invention, and of course, it should also be understood that the multi-component sealing material of FIGS. 1 and 5 may be used in the apparatus of FIG. 7 by providing a separator therein in essentially the same manner as illustrated in FIG. l. The piston 220 is a single piston in the form shown in FIG. 7, and a single disk 223 is preferably provided. Only a single sealing head 15 may be employed with the apparatus of FIG. 7, although a plurality of such heads 15 such as illustrated in FIGS. 3 and 6 maybe employed in the FIG. 7 form of the invention if so desired. The ball valve 25 is preferably omitted from the form of the invention shown in FIG. 7, in which case the flexible bag 26 is also omitted. The discharge or forcing of the sealing material S outwardly through the flexible head 15 after it has been positioned in a hole H in a pipe P in the same manner as illustrated in FIG. 2, is accompanied by firing an explosive 35 above the piston 220. The explosive is a shotgun shell or other powder which is detonated by an electrical spark from electrical wires 36 which extend to the surface of the well and are connected with a suitable source of electrical voltage for creating the spark to ignite the explosive. The cap 222 is closed so that the fluid does not enter the area above the piston 220, whereby the explosive 35, is kept dry at all times.

The operation of the apparatus of FIG. 7 is essentially the same as that illustrated and described in connection with FIGS. 1-4, except that the force of the explosion from the explosive 35 is utilized for causing the piston 220 to force the sealing material S downwardly and out through the openings in the flexible head 15 instead of using the fluid pressure differential within the well pipe. Thus, the apparatus A-2 is especially useful when the differential pressure in a well pipe is insufficient to force the sealing material S outwardly into the area externally of the pipe P. This might occur when the well formation pressure externally of the pipe P is high and therefore difficulties are encountered in developing a suflicient differential fluid pressure to drive the sealing material S outwardly. It should be noted that since the apparatus A-2 preferably has only a single flexible head 15, the support 221 preferably is a wire line which has a rotating tool of known construction thereabove (not shown) for rotating the apparatus A-2 during the raising and lowering of same to thereby facilitate the insertion of the head 15 into the hole H.

The form of the invention illustrated in FIGS. 8 and 9 is designated A-3 in the drawings. Such apparatus A-3 has a receptacle 310 having a flowable material S therein which may together with the fluid in the head 312 form a compound that hardens. A piston 320 is disposed in one end of the cylinder or receptacle 310, and such piston 320 is exposed to the fluid pressure in the well pipe P through an opening 322. The piston 320 has an O-ring 32011 and a resilient snap ring 320b therewith. The resilient snap ring 320b slides along the inside surface of the cylinder or receptacle 310 until the snap ring 320b is opposite an annular groove 310f in the inside wall of the receptacle 310. At that point, the snap ring 32017 is adapted to expand by the resiliency of the material of the snap ring 320b and it enters the groove 3101 so as to thereafter lock the piston 320 in the innermost position within the cylinder or receptacle 310 (FIG. 9). The pipe engaging element 312 corresponds with the pipe engaging element 12 of FIG. l, and it preferably includes a resilient layer 31211 of rubber, plastic or other material which forms the surface for contacting the inner surface of the pipe P (FIG. 9). The layer of material 31211 may be formed integrally with the flexible head 315 which has a hollow interior 31511 and which is in fluid communication with the receptacle 310 through an opening 31511. A ball 325 together with a spring 32511 are disposed in the flexible head 316 so that if a part of the material S is to be' separated from the other part, the ball 325 serves as a separator, whereby one component may be in the receptacle 310 and the other component may be in the interior 31511' of the flexible head 315 (to the right of the ball 325 as viewed in FIG. 8).

The apparatus A-3 is lowered on a wire line or cable 321 which preferably is connected with a rotating tool of conventional construction or any other suitable construc tion (not shown) so that the flexible head 315l may be moved to different positions to facilitate the insertion thereof in a hole H such as shown in FIG. 9 of the drawings. The lower end of the cable 321 is secured to the receptacle 310 by a ring 32111 which is welded, or otherwise secured to the housing or cylinder 310.

In the operation or use of the form of the invention illustrated in FIGS. 8 and 9, the apparatus is manipulated in the well in the same manner as explained heretofore in connection with FIGS. 1-4 so that the apparatus A-3 is lowered below the hole H to be plugged and is raised upwardly above such hole until such time as the differential fluid pressure in the well moves the flexible head 315 into the hole H. After the resilient material 31211 on the pipe engaging element 312 has seated itself against the inside surface of the pipe P so as to initially close the hole H the iluid pressure differential between the inside of the pipe P and the outside thereof is sufficient to force the piston 320 from its original position (FIG. 8) to the right and thus to its discharged position (FIG. 9). The iluid in the cylinder or receptacle 310 is discharged through the opening 31511 and it mixes with the fluid in the chamber or interior 315d of the flexible head 315. Since the piston 320 forces a greater amount of fluid into the interior 31511 of the flexible head 315 than was initially therein, the flexible head 315 is expanded or stretched so that it normally assumes a substantially globular or spherical shape such as illustrated in FIG. 9 to accommodate the additional material. The material S then preferably solidifies or hardens and because of the difference in the shape of the flexible head 315 the diameter of the flexible head 315 is then greater than the diameter of the hole H to prevent the return of the ap paratus A-3 back into the pipe P. The ball 325 serves as a closing means for closing the hole 31511 and it also facilitates the distortion of the flexible head 315 to the enlarged shape as best seen in FIG. 9.

After the sealing material S has hardened within the enlarged head 315 to substantially the shape shown in FIG. 9, `the apparatus A-3 may be severed at a suitable point such as a score line or ring 310g, and such severing can be accomplished by applying jarring forces to the receptacle 310 through any conventional type of wireline jars or weights on the wireline 321.

In FIGS. 10 and 1l, a modified form of the apparatus A-4 `is illustrated and it is of a type which is adapted to be dropped in the pipe P without any cable or other supporting line. The device A-4 includes a receptacle 410 which has two compartments 41011 and 410b which are interconnected with an opening 410e` having a ball 425 or other suitable movable closure element between the cornpartments 41011 and 410b. Within the compartments 41011 and 410b, the sealing material S is disposed, and it may be of the epoxy type having two or more components which are maintained separately from each other until such time as it is desired to solidify same. The receptacle 410 is joined at an intermediate point by a circular disk or plate 412 which also serves as a pipe engaging element. The compartments 41011 and 41011 are filled by any suitable means. As illustrated in iFIG. 10, a passage 41211 extends from the outer edge of the element 412 inwardly to one side of the ball 425 for filling the compartment 41011. After the compartment 41011 is filled, the passage 41211 is closed off by a suitable plug 412k. Another passage 412e` establishes communication from the outer edge 412 t0 the compartment 410b to the right of the ball 425, and it also has a suitable plug 412d for closing same after iluid fills the compartment 410b. The element 412 is preferably a plate made of steel or relatively heavy material as cornpared `to the receptacle 410 and the liquid sealing material S therein, so that when the apparatus A4 is dropped in the fluid within a pipe P, it falls downwardly therein with the plate 412 substantially vertically as shown in FIG. 10. The outer ends of the receptacle 410 serve as the flexible heads 415, one of which is adapted to fit within the hole H and the other end of which is collapsed as illustrated in FIG. l1 so as to discharge the contents from one end of the compartments 41011 or 41011 into the other of such compartments to mix the two components of the sealing material S together so as to enlarge the compartment in which the contents of the sealing material S are finally disposed (FIG. ll) to a diameter which is greater than the diameter of the hole H. Therefore, after the sealing material S has hardened, the hole H is plugged or closed and the assembly A-4 is retained in position and cannot be dislodged therefrom.

In the operation or use of the apparatus of FIGS. l and 11, the apparatus A-4 is lowered or dropped in the fluid such as the well fluid within the pipe P. A differential pressure is created or exists across the hole H which is to be plugged so that there is a greater pressure internally of the pipe P than externally thereof. When the apparatus A-4 reaches the vicinity of the hole H, the velocity of the fluid moving through the hole H draws and forces the apparatus to move towards such hole H and the head 415 on one end of the compartment `410` moves through the hole H to bring one 'side of the p-ipe engaging element 412 into contact with the inside of the pipe P' at which time substantially all of the flow of the fluid from the inside of the pipe P to the area externally thereof is cut off. When such condition occurs, the fluid pressure internally of the pipe P, being greater than that externally, causes a collapse of the receptacle 410 on the inside of the pipe P and this initially forces the ball 425 Iinto the portion of the receptacle 410 which is externally of the pipe P (FIG. 1l). Then, the por-tion of the sealing material S which is in the compartment 410a is forced or squeezed through the opening 410e and lit mixes with the portion of the sealing material in the compartment A10-b so that they then are mixed together and react chemically to solidify into a solid. Due to the increased amount of the material S within the compartment `410b after the contents of the compartment 410a have been forced into the compartment 410b, the diameter of the compartment 410b is enlarged to a diameter greater than that of the hole H (FIG. 11) so that after the sealing material S has solidified it cannot return back into the pipe P.

Instead of dropping the apparatus A-4 by itself, a wire line carrier (not shown) may be used for connecting a plurality of such units A-4 together at different points on the wireline carrier so that as each of the units A-4 enters a hole lit detaches itself from the wire and the remaining units A-4 'are then worked up and down in the well to seal or close other holes or perforations until they are all plugged.

In the form of the invention illustrated in lFIGS. 12-l4, the apparatus A-S is essentially the same as that illustrated in FIG. and like parts bear like numerals, although it is shown as having only a single component sealing material S therein and therefore the dividing plate 110C has been omitted.

In the form of the invention illustrated in FIGS. 12-14, the pipe engaging element 512 is utilized instead of the pipe engaging element 12 and the flexible head 15 of FIGS. l and 5. The pipe engaging element 512 may be of different configurations such as illustrated at the 512 and 512 in FIGS. 13 and 14, and they are adapted to seal around holes, cracks, or openings H*1 of different shapes and configurations. The pipe engaging element 512 has a plurality of holes 512a distributed over its inside surface which are surrounded by a sealing ring 512b. The sealing element 512 also has holes 512a and a sealing ring 512b. The seal ring 512b is Iadapted to t into sealing engagement with the inside surface of the pipe P around the crack, split, hole or other opening H-1 so as to seal off the fluid within the pipe P from such opening H-L When this occurs, the fluid pressure within the pipe P functions to squeeze the receptacle wall 110- to force the sealing material S outward- 1y through the openings 512a so as to form a mass of the sealing material S in the hole H-l and just externally thereof for forming `a plug or closure for such hole H-l. A decentralizer which includes a spring 60 mounted on a support bar or rod `61 suspended from the lower end of the apparatus A-S is utilized for maintaining the element 512 in relatively close proximity to the inside of the pipe P to facilitate its engagement and sealing around the opening H-1 when the element 512 is disposed in proximity to such opening H-1. The differential fluid pressure within the pipe P serves to effect the movement of the element 512 into contact with the inside surface of the pipe P for such sealing engagement between the seal 512b and the inside of the pipe P. The apparatus A-5 may be rotated by any suitable rotating tool to facilitate the location of the element 512 over the hole or opening H-1.

The operation or use of the apparatus A-5 is essentially the same as that described heretofore in connection with FIG. 1. Thus, the Iapparatus A-5 is lowered and raised alternately and is preferably also rotated until such time as the movement of the fluid from the inside of the pipe P to the area externally thereof forces the element 512 into sealing contact with the area surrounding the hole H-1. When that occurs, the differential in pressure of the fluid within the pipe P as compared to that externally of the pipe P is sufficient to compress the flexible wall of the receptable and force the contents of the receptacle, namely the sealing material S, outwardly through the chamber 511 and then the openings 512a to the area externally of the hole H-1 in the vicinity of same. The entire apparatus A-5 is permitted to remain in position a sufficiently long time for the sealing material S to solidify or harden and then the apparatus may be detached by pulling upwardly or jarring same downwardly. The element 512 may be detached with -the rest of the apparatus A-5, or shear areas may be provided for severing the element 512 olf from the rest of the apparatus so as to leave the element 512 in position over the the opening Hel after the rest of the apparatus A-S is moved upwardly in the well.

Although the invention has been described with a flowable material or fluid for forming the closure or plug in the hole H, the invention is not limited thereto since any material, such as deformable metals, inserted through the hole H for serving as a closure material for the hole H may be used.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

What is claimed is:

1. Apparatus for closing an opening in a well pipe comprismg:

a pipe engaging element adapted to engage the inside wall of the well pipe and adapted to be moved into position over said opening by the flow of fluid from 1nside of the well pipe through the opening in the well pipe;

said pipe engaging element having a sealing surface for sealing engagement with the inside wall surrounding said opening in the well pipe to substantially close off fluid flow through said opening; and

receptacle means with said pipe engaging element and having closure material therein for introduction through said opening to the area externally of said Well pipe for closing said opening.

2. The structure set forth in claim 1, wherein said sealing surface is flexible and including:

a plurality of discharge ports through which fluid flows for discharging -material through said opening and externally of said well pipe.

3. The structure set forth in claim 1, including:

means mounting said receptacle means on one side of said pipe-engaging element;

a flexible head disposed on the other side of said pipe-engaging element; and

passage means in said element for the flow of fluid from said receptacle means to said head after said head is disposed through said opening.

4. The structure set forth in claim 3, including:

a removable closure in said passage means to maintain the fluid in said receptacle means until discharged into said head.

5. The structure set forth in claim 1, including:

a flexible head having a diameter equal to or less than that of said opening in the well pipe and adapted to extend through said opening', and

said head being adapted to be expanded to a diameter greater than that of said opening in the well pipe while said head extends through the opening.

6. The structure set forth in claim 5, including:

a ball check valve inside of said flexible head for per- -mitting lluid to enter said head but for preventing the return thereof from said head.

7. The structure set forth in claim 5, including:

means for forcing material into said head from said receptacle means by iluid pressure in the well pipe after the pipe engaging element has seated itself in engagement with the inside surface of the well pipe.

`8. The structure set forth in claim 7, wherein:

said means for forcing the sealing material into said head includes a piston in said receptacle means which is moved by fluid pressure in the well pipe after the pipe engaging element has seated itself in engagement with the inside surface of the well pipe.

9. The structure set forth in claim 7, wherein said means for forcing material into said head includes a pistion operable, by pressure in the well pipe.

10. The structure set forth in claim 1, including:

a head adapted to enter the opening in the well pipe;

port means establishing fluid communication from said receptacle means to said head; and

means for forcing the sealing material from said receptacle means through said port means of said receptacle means after said head is in said opening.

11. The structure set forth in claim 10, wherein:

the wall of said receptacle means is flexible and serves as said means for forcing the sealing material from the receptacle means when it is squeezed by the iluid pressure in the well pipe for discharging same from said receptacle means.

12. The structure set forth in claim 11, including:

means for separating said receptacle means into two compartments for thereby retaining two components of a sealing material separate from each other until discharged together from said receptacle means for mixture and hardening in an area externally of the opening in the well pipe.

13. The structure set forth in claim 10, including:

a plurality of flexible heads disposed at different radial positions relative to said receptacle means;

means establishing fluid communication between all of said flexible heads and said receptable means; and

check valve means in each of said heads for preventing lluid in the well pipe from entering any of said heads, but permitting an opening of the one of said heads which is subjected to a differential iluid pressure when it is in the opening in the well pipe.

14. The structure set forth in claim 10, wherein:

said means for forcing the sealing material from said receptacle means includes an explosive which is adapted to be detonated for providing a force on said sealing -material to discharge same from said receptacle.

15. The structure set forth in claim 10, wherein:

said pipe engaging element is a disk which is disposed substantially mid-way between said receptacle means and said head;

passage means are provided in said element for the tlow of material from said receptacle means to said head; and

said passage means is closed by a removable closure until said flexible head enters said openng.

References Cited UNITED STATES PATENTS 2,933,136 4/1960 Ayers et al. 166--284 3,292,700 12/1966 Berry 166-284 3,376,934 4/1968 Willman et al. 166-284 X 3,379,251 4/1968 Bohn 166-286 3,399,726 9/1968 Harris et al. 166-284 3,437,147 4/1969 Davies 166-284 DAVID H. BROWN, Primary Examiner U.S. C1. X.R.