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Publication numberUS3292700 A
Publication typeGrant
Publication dateDec 20, 1966
Filing dateMar 2, 1964
Priority dateMar 2, 1964
Publication numberUS 3292700 A, US 3292700A, US-A-3292700, US3292700 A, US3292700A
InventorsBerry William B
Original AssigneeBerry William B
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and apparatus for sealing perforations in a well casing
US 3292700 A
Images(3)
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Description  (OCR text may contain errors)

Dec. 20, 1966 w. B. BERRY 3,292,700

METHOD AND APPARATUS FOR SEALING PERFORATIONS IN A WELL CASING Y Filed March 2, 1964 5 Sheets-Sheet l Hei,

"INVENTOR wlLLlAM B. BERRY A TTOR NE YJ Dec. 20, 1966 w. B. BERRY 3,292,700

METHOD AND APPARATUS FOR SEALING PERFORATIONS 1N A WELL CASING Filed March 2, 1964 5 Sheets-Sheet 2 llkIIlI-lli lll INVENTOR.

WILUAM B. BERRY Dec. 20, 1966 w. B. BERRY METHOD AND APPARATUS FOR SEALING PERFORATIONS IN A WELL CASING sheets-sheets Filed March 2, 1964 FiGII INVENTOR,

WILLIAM B. BERRY BY /v/mm FIGB ATTORNEYLS United States Patent C) 3,292,700 NIETHOD AND APPARATUS FOR SEALING PERFORATIONS IN A WELL CASING William B. Berry, P.0. Box 1951, Clarksburg, W. Va. 26401 Filed Mar. 2, 1964, Ser. No. 348,493 20 Claims. (Cl. 166-21) This invention relates broadly to the treating of wells and more specifically to the closing or sealing of perforations in the casing of the well.

In well drilling operations the use of a stimulation method in treatment, such as hydraulic fracturing, has greatly stimulated and increased the permeability and porosity of the producing or potentially producing zones in a well bore. The hydraulic fracturingroperation is usually carried out after a well has been drilled, the production tubing or casing run yand cemented in place and the Well logged with the potentially productive zones identified in the conventional and customary manner. A productive zone is then exposed by perforating the well tubing or casing in the customary manner. The productive zone is then subjected to'hydraulic fracturing by the pumping of water, oil or other liquids which might carry certain solid agents through the perforations in the well casing and into the zone. The uidic material so pumped under high pressure is intended to rupture the zone and form passageways therein While maintaining said passageways in a substantially open or porous state through which the oil or gas in the formation may'then escape'into the casing disposed within the bore ofthe well. The foregoing type of operation is readily adaptable to a well having only a single zone capable of producing oil or gas.

In Wells wherein the log of various tests would seem to indicate that there was a possibility of developing a plurality of zones, the problem of being able to treat one zone by perforating same and then subjecting it to a hydraulic fracturing operation and then isolating or separating this treated zone from the next zone to be so treated has often been of such a magnitude as to result, in having what could be a multi-zone well remain as `a single zone well, without any attempts being made to stimulate more than one zone. While the use of packers, plugs and other similar devices have been successfully employed in a multi-zone stimulation procedures for the purpose of isolating or separating one zone from the next, there have arisen many ycost and operational problems which very often result in a potentially multi-zone well being operated as a single zone Well. While packers, plugs and the like have been placed Within a well casing for separating or isolating a plurality of Zones, the removal of said plugs, packers and the like have generally presented additional recovery problems in order to bring the various zones into operation when making the Well a producing one. One of the factors which in many instances has been a deterrent to the undertaking of a multi-zone operation is the cost of removing the plugs, packers and the like. Thus, it has been found that plugs, packers and similar devices do not completely fulll the demands of the industry in multi-zone operations.

In recent years, various methods and types of apparatus have been devised for introducing into the -well casing balls or spheres of appropriate size for the purpose of seating upon the perforations formed in the casingin an effort to effectively seal the treated zone from the Well bore. The patent to Derrick et al. 2,754,910 of July 17, 1956, illustrates one method of introducing balls or spheres into a well casing for the purpose of closing or sealing the perforations formed in said casing in the area of the treated zone, While the patent to Holt 3,011,548 of December 5, 1961, illustrates another method and apparatus lCe utilizing balls or spheres for closing and sealing the perforations formed in said casing. The teachings of said patents have met With considerable success and have deflnitely proven, in the majority of instances, to have an advantage over the use of plugs, packers, and the like in permitting successive zones to be treated while separating or isolating treated zones.

While the method and apparatus as disclosed in the Holt Patent 3,011,548 has provided an operator with more .control than prior methods over the delivery of the sealing balls or spheres to the perforations in the well casing, it has been determined that a still more positive control is desired over the delivery of the balls or spheres and the seating of the balls on the perforations. It 'has been ascertained that where the balls or spheres derive their locomotion and manipulation to the iiuid moving through the Well casing and perforations into the treated zone, that said balls or spheres do not in all instances effectively seal off desired or selective perforations in a particular zone.

The present invention is intended to overcome the various shortcomings found to exist in prior devices, particularly as concerns the delivery of sealant members to a perforated zone in a Well casing and the placing of said -members in engagement with the perforations for the purpose of effectively sealing said perforated area. In the present invention, the sealant members are lowered in a Well casing to the .perforated zone by means of a transporter which is under the control of an operator at all times. When the transporter has been lowered to the desired level, the sealant members are exposed or released therefrom so as to be capable of limited movement in a .fluid medium that is being pumped into the well casing and flowing through the perforations into the treated zone of the well, but still remaining under the control of the transporter. The sealant members are attached to a member carried by the transporter by means of ilexible pliable elements that are capable of being broken by the movement of the transporter in opposition to the Aholding force of the hydraulic pressure of the fluid at the time 'of or just after the sealant members seat upon the perforations for effectively sealing same against the passage of iluid therethrough.

One of the objects of the present invention is to provide a novel method and apparatus of introducing into a perforated well casing a plurality of-members for engaging and effectively sealing the perforations in said casing.

Another object is to provide a transporter to carry a plurality of sealant members into a well casing having a perforated area or zone for delivering said members to said area un'der the control of the transporter.

Another object is to provide a transporter having a plurality of sealant members that is introduced into a perforated a-rea or zone of a well casing to deliver said members to said area` for kclosing and sealing said perforations.

A further object is to provide a plurality of sealant members connected to a carrying member that is positioned ,Within a transporter which is introduced into a well casing having a perforated area or zone for delivering said sealant members to the perforated area while still connected to the carrying member and under the control of the transporter.

A still further object is to provide a plurality of sealant members connected to and carried by a transporter which isintroduced into a Well casing having a perforated area or zone delivering said sealant members to the perforated area Where said members are .removed from the transporter and seat upon the peforations for elfectively sealing same.

Another object is to provide a plurality of sealant members connected to and car-ried by la transporter which is introduced into a Well casing having a perforated area or zone and which transporter is under the control of an operator to provide the maximum degree of eciency for placing the sealant members opposite the perforations whereby the sealant members will be detached from the transported contemporaneous with their closing and sealing the perforations in the casing.

Other objects and advantages, more or less ancillary to the foregoing in the manner in which all of the various objects are realized, will appear in the following description, which, when considered in connection with the accompanying drawings, sets forth the preferred embodiment of the present invention.

Referring to the drawings wherein the preferred embodiment of the invention is illustrated:

FIGURE l is va vertical sectional view of a cased earth Well showing the casing perforated at a fractured zone and illustrating conventional Well head equipment;

FIGURE 2 is an enlarged vertical sectional view through a portion of the casing of the well of FIGURE 1 showing a transporter, partly in section, carrying sealant members therein;

FIGURE 3 is an enlarged vertical sectional view similar to FIGURE 2 and showing the transporter and sealant members in position for delivering the sealant members to the perforations in the casing;

FIGURE 4 is an enlarged detailed sectional view of the lower end of the transporter shown in FIGURE 2;

FIGURE 5 is an enlarged detail View of the lower portion of the transporter shown in FIGURE 3;

FIGURE 6 is an enlarged detailed sectional view of another portion of the transporter shown in FIGURE 3;

FIGURE 7 is an enlarged detailed sectional view of a portion of the transporter shown in FIGURE 2 illustrating the positioning of the sealant members within the transporter;

i FIGURE Sais a side elevational view of a sealing member that may be used with the transporter shown in FIGURE 2;

FIGURE 8b is a side elevational view of another form of sealant member that may be used With the transporter shown in FIGURE 2;

FIGURE 8c is a perspective view of still another form of sealant member that may be used with the transporter shown in FIGURE 2;

FIGURE 9 is an enlarged vertical sectional view of a modified form of transporter and sealing members;

FIGURE 10 is an enlarged vertical sectional view of the modified transporter shown in FIGURE 9 illustrating the sealant members in position for seating upon the perforations in the well casing; and

FIGURE 11 is an enlarged detailed view partly in section of the weighted member connected to the lower end of the transporter shown in FIGURE 9.

Referring to FIGURE l of the drawings there is shown a conventional Well bore having disposed therein the usual outer or surface casing 15 which has mounted therein, in the customary manner, an inside or production casing string 16 upon which is mounted a control valve 17. The production casing string 16 extends through the various formations in the well bore and terminates at the end or bottom of said bore. The control valve 17 has connected thereto a Well head assembly or unit 18 that has supported thereon a well head lubricator or launch tube assembly by which the well is maintained in locked internal control regardless of pressuresV generated within the bore. The well head lubricator or launch tube assembly does not in and of itself constitute a part of lthe present invention but same is employed in a multizone operation wherein it is necessary and essential to introduce into the casing 16 various types of equipment or apparatus and it is essential that the pressure be maintained within the well bore at all times that such apparatus or equipment is being either introduced or removed therefrom. As concerns the present invention, it would be suicient to state that the well head lubricator or launch tube assembly mounted on the well head unit 18 is provided with a cross head structure 19 that has control valves 20. The cross head has supported thereon in operative relation therewith a launch tube control valve 21 which in turn supports a launch tube 22 tha-t is provided with a quick coupling 23 to facilitate its ready attachment or detachment from the control valve 21 so that various pieces of apparatus or equipment may be either inserted into the launch tube or removed therefrom. It is through theruse of the valves 17 and 21 that thek pressure within the well Abore may be maintained and also introduced into `the launch tube so that the pressure within the launch tube will be equal to the well bore pressure and thus provide for a balance condition prior to the lowering of equipment or apparatus into the well bore. duction casing string 16 is shown in FIGURE l as extending through what are considered to be, based upon data obtained from previous tests, two potential producing formations A and B, and furthermore, the casing or string has been anchored or secured in place by a conventional cement sheath 26. In addition, casing 16 has been perforated at formation A and said formation has been stimulated by subjecting same to hydraulic fracturing whereby passageways have been created or developed in said formation through which the oil or gas may readily ow or pass to the well bore and thence through the perforations into the casing or production string l16. Thus, it becomes necessary to close or seal the perforations 27 in the casing 16 opposite zone A before it is at all appropriate or feasible to perforate the casing in zone B and subject -this zone to a stimulation treatment through hydraulic fracturing.`

There is shown in FIGURE 2 a transporter assembly having a plurality of sealant members mounted in and carried thereby which are being lowered from the well head through the casing 16 by means of a conventional wire line 28. The transporter includes an elongated hollow tubular member 29 that has secured to its uppermost end, by any suitable means, a solid metal body member 30 that is of a configuration complementary to that of the tubular member 29 and which acts as a weight in the lowering of the 4transporter in the casing. The solid body member 30 has affixed to its peripheral surface at space points a plurality of bowed spring members 31, which are adapted to engage the vinner surface of the casing 16 r for the purpose of centering and guiding the transporter` as it is being lowered from the well casing head to the perforated zone that is to be closed or sealed. The solid body member 30 has aflixed to its upper end, in any suitable manner, a tapered socket member 32 which is`connected -to the wire line 28 upon which the transporter is lowered in the casing 16.

The tubular member 29 has mounted therein at its uppermost end a base member 35 which has secured thereto, in vany suitable manner, one end of a depending telescoping rod assembly 36. The lowermost rod of the assembly 36, FIGURE 3, has aflxed thereto a piston or mandrel 37, FIGURE 6, that is formed with diametrically disposed slots 38 which have mounted therein spring fingers or members 89 that slidably engage the inner surface of the tubular member 29 during the movement of the pistonk or mandrel from its inoperative or retracted position to its operative position. The lowermost end portions of the spring fingers 39 are intended to Hex or flare outwardlyl from the lower end of the tubular member 29 when the mandrel 37 is at its extended or operative position,A

The inner or pro-V ing stem 41 that terminates in or has mounted thereon a hub or boss 42. The hub 42 has secured thereto by any suitable means the ends of a plurality of arcuate-shaped spring elements 43 which function as a guide member. As illustrated in FIGURES 2 and 4 `there are two pairs of spring elements 43 with the elements of each pair being diametrically disposed with respect to one another and with one pair of elements 43 having their lower ends secured to or anchored in a tapered cone member 44. The other pair of spring elements have their lower ends slidably disposed in slots 45 formed in said cone member 45 to permit a slight degree of flexing by said elements. The pairs of spring elements 43 which constitute a guide member are suspended from the hub 42 so that in their inoperative position or condition only the uppermost portions of the elements 43 are positioned within the lowermost end ofthe tubular member 29. The carrying stem 41 is retained Within the tubular member 29 and the guide member 43 is maintained in engagement with the lower end of the tubular member 29 by a plurality of trigger members 46 that are pivotally connected to lugs or projections 47 mounted on the pair of spring elements 43 that have their lower ends slidably mounted in the slots 45 in the cone member 44. The trigger members 46 are retained in an outwardly flared position with respect to the tubular member 29 and guide member 43 by means of a sheer pin or wire 48 that is connected to a shoulder or abutment 49 on the outer surface of the tubular member 29 and to an opening or aperture 50 formed in each trigger member 46 adjacent its pivotal connection to the guide member 43. The elements of the guide member 43 have mounted thereon subjacent the lugs 47 one end of a spring finger member 51 with the other end of said spring finger being flared outwardly for engagement with the trigger members 46 so that once the sheer pin or wire 48 has been broken the spring fingers will move the trigger members 46 about their pivotal connection to the lugs 47 so that said trigger members will lie in planes parallel to the carrying stem 41 in the manner as shown in FIGURE 5.

The carrying stem 41 is provided at spaced points throughout its length with projections or abutments 54, FIGURES 3 and 7, which may be formed integrally with the stem or mounted thereon by any suitable means, not shown. The projections 54 are provided with suitable screws 55 for securing thereto one' end of a string or thread 56, which may be formed of nylon or similar material, while the other end of the string 56 has aixed thereto a spherical sealant member 57. It is to be noted, FIGURE 7, that the projections 54 not only serve to secure to the carrying stem 41 one end of the suspension or control string or thread 56 and in turn the spherical sealant members 57 but also function as a seat or support for the sealant members that are connected to the next subjacent projection 54 on the carrying stem 41. The spherical members 57 are intended to become separated from the carrying stem 41 through the breaking or severing of the suspension or .control thread 56 after being drawn into or contemporaneous with being drawn into engagement with the perforations 27 in the casing 16 for the purpose of sealing said perforations. The sealant members 57 need not be of spherical configuration but may assume various forms and shapes and in t-urn may be formed of any suitable material which .could be metallic, rubber, or plastic in nature or said membersrcould readily be a composition of different types of materials. As an illustration, the sealant members could be formed having a hard center core with an outer layer of semiflexible neoprene or Ysimilar material so that it would have certain inherent resilient characteristics and be capable of seating upon the perforation 27 in the casing V16 and being partially attened upon said perforated area due to the hydraulic pressure in said casing. The sealant member`57 as shown in FIGURES 3 and 7, need not be of spherical shape but could very readily have a pear shape such as shown in FIGURE 8a or it could assume an elongated or tapered end shape similar to the conguration of a lemon such as shown in FIGURE 8b or it could have the shape of a rectangle, such as illustrated in FIGURE 8c, where in lieu of closing or sealing a perforation in the casing 16, it could be used to seal a gap or split that might have formed or developed in said casing during the fracturing operation.

In the use and operation of the transporter and sealant members of the present invention, it is to be assumedthat the well has been drilled, the casing run and cemented in place followed by a perforating operation and a hydraulic fracturing or stimulating operation of one of the producing zones, preferably, but not necessarily the lowermost Zone. Upon the completion of the hydraulic treatment, the' perforationsin the casing have to be sealed so the operator can advance to the next selected zone for the purpose of subjecting this zone to a perforating operation, a hydraulic or stimulating treatment and then the sealing or closing of the perforations in the casing in order to advance to the next zone.

In preparing or loading the transporter assembly with the sealant members S7, the carrying stem 41 is withdrawn from the tubular member 29 and said tubular member and carrying stem are inverted so that said carrying stem is projecting above the tubular member while the control or suspension threads 56, which are already fastened to the sealant members 57, have their free ends secured to the screws 55 onthe projections 54. After the carrying stem 41 has been loaded with the sealant members 57, the tubular member 29 is then slid over the sealant members and carrying stem 41 and at the same time, `the rods 36 are telescoped within one another contemporaneous with the retraction or movement of the piston 37 within the tubular member 29 towards the base member 35. Once the piston 37 and carrying vstem 41 have been moved to their inoperative positions so as to be entirely within the tubular member 29, the sheer pin or wire 48 is connected to the shoulders 49 at 4the end of the tubular housing or member 29 and through the apertures 50 in the trigger members 46 so that the carrying stem and sealant members are retained within the tubular member 29 by means of the sheer pin or wire 48. After the carrying stem 41 and sealant members are secured within the tubular member 29, the transporter assembly is then inverted or turned to its operative position wherein the carrying stem 41 is then in a position to be projected below the tubular member 29. In this operative position, the sealant members 57 will then be seated upon the projections 54 in the manner as illustrated in FIGURES 2 and 7.

The transporter having been so assembled or loaded is then placed in the launch tube 22, FIGURE l, and through suitable manipulation of the various valves 17, 20, and 21, lthe fluid injections of the hydraulic treatment are either temporarily halted or materially reduced in pressure so that the transporter assembly can then be lowered by means of the wireline 28 into the casing 16 of the well bore. As the transporter assembly is being lowered in the casing 16, the spring guide members 31 maintain it substantially in the central portion thereof and at the same time, the trigger members 46 are moving downwardly over the inner surface of the casing 16 which is to be closed or sealed by the sealant members 57. When the transporter assembly has been lowered to the desired depth, that is, at a point preferably below the perforated casing area, the assembly is through the retraction of the Wire line 28 slowly raised in the casing 16 until such time as the ends of the trigger members 46 engage a collar or connector, not shown, that is commonly employed in coupling or joining lthe tubing sections or strings constituting the inner casing 16. Upon the trigger membersengaging such a collar or connector and through the continued raising or elevating of the transporter 'assembly by means of the wire line 28, the sheer pin V48 will be broken thus permitting the carrying stem and guide member 43 together with the sealant members 57 to move downwardly from and out of the tubular member 29 of the transporter assembly under the weight of the carrying rod 41 and its associated elements as well as the force imparted thereto by the piston 37 through its movement downwardly in the tubular member 29 until such time as the carrying stem 41 and sealant members 57 have been completely discharged or ejected from the tubularmemberv29. When the carrying stem has been completely discharged or ejected the piston 37 will be at the bottom or lower end of the tubular member 29 and the lower portions of the spring fingers 39 will be flexed or llared outwardly of the tubular member for holding or retaining said piston and carrying stem 41 in their extended or operative position with respect to the tubular member 29. Upon the breaking of the sheer pin or wire 48 and the downward movement of the guide member 43 and carrying stem away from the lower end of the tubular member 29, the spring members 51 will cause the trigger members 46 to pivot about the lugs 47 so that said trigger members project upwardly in planes parallel to the longitudinal axis of the carrying stem 41 whereby the guide member 43 will be able to have a free and unimpeded movement downwardly in the casing 16 to facilitate in the withdrawing of the carrying stem and sealant members from the tubular member 29. The sealant members 57 upon moving out of the tubular member 29 fall off of the projections 54 and are suspended from the screws S by the carrying or control threads 56 so that they assume a position that is representative of a long pod or bunch of grapes. The manner of supporting the sealant members upon one projection 54 on the carrying stem 41 while having the other or free end of the control or suspension thread 56 secured to the next subjacent projeciton 54 enables the control or suspension thread 56 to drag or draw the sealant members out of the tubular member 29 during the period in which the carrying stem 41 is moving out of or below the tubular member 29 and thus insures a free movement of the carrying stem and sealant members by avoiding any bunching or gathering of the sealant members within the tubular member, which type of arrangement might readily jam or impede the movement of the carrying stem from the tubular member 29.

The transporter assembly with the depending carrying stem 41 and sealant members 57 are slowly raised in the rated from the carrying stem by breaking the control thread 56 thus leaving the sealant member 57 seated upon the perforation for sealing same. As the transporter assembly continues its upward movement in the casing 16,l

the lowermost perforations will become sealed by the uppermost sealant members on the carrying stem 41 and the area of static condition will increase in the casing until tinally all of the perforations 27 will have been closed by a sealant member 57.

Upon the seating of the sealant members 57 upon the perforations 27 in the casing 16 in the zone A, it will be necessary to maintain a minimum well head pump pressure, commonly known as a holding pressure, in order to insure the retention of the sealant members on each and every perforation while the transporter assembly is removed from the casing 16 and the zone B is then subjected to a sequence of operations of perforating, hy-

' draulic fracturing, and treatment and ushing operation casing 16 by means of the wire line 28 and at the same time flush uid injections into the casing 16 are reestablished through thevalve 20 with a corresponding flow through the perforations in the casing and into the treated zone. Thus, a static condition is created or remains in the well bore fluid below the perforated area or zone so that it is highly desirable to effect the ejection or discharge of'the carrying stem 41 from the tubular member 29 in this area so that thesealant members will be disposed or positioned within a static condition zone and be out of the range of fluid turbulence which would be occasioned by the flushing fluid moving through the perforations of the casing 16 and into the treated zone. As the transporter assembly advances up-hole by means of the wire line 28, the sealant members 57 secured to the end of the carrying stem adjacent the piston 37, FIGURE 3, will be moved into the area of the perforations and due to the movement of the flushing fluid, the uppermost sealant members would be drawn over to the lowermost perforations in the casing 16. The various sealant members will remain under the control of the operator through the transporter assembly and the suspension threads 56 until the time that a sealant member is drawn ontoV and seated over a perforation 27 in the casing 16, as at this stage, the suspension or control thread 56 will be broken due to the'hydraulic pressure of the flushing liuid in holdking the sealant member on the perforation 27, and the tension pull applied by the slow and steady upward movement of the carrying stem in the casing. The upward movement of the carrying stem, even though said movefollowed by the sealing of the perforations in said zone.l

Thus, as one zone is treated and'sealed, the next zone is subjected to the same treatment and sealing operation, the treated zones will remain in a sealed condition until such time as it is found desirable to bring the well into operation through removal of the sealant members 57.

The modified transporter assembly shown in FIGURESy 9 through 11'V is identical in many respects to the transporter assembly shown in FIGURES 2 and 3, and the tween the sealant members when said members and chain The are positioned within the tubular member 29. lowermost end of the chain 61 is connected to a tapered weight or guide member 63 that has a plurality of resilient fingers 64 mounted on its outer surface. The tapered weight or guide member 63 is provided with trigger members 46 that are spring biased to a closed or seated position, FIGURE 1l, by means of the spring members 51.

The transporter assembly shown in FIGURES4 9 through ll is operated in the same manner as that shown in FIGURES 2 and 3 in that the trigger members 46 engage a collar or coupling connection in the casing 16 so that as the transporter assembly is being raised in the` casing 16, the sheer pin or wire connecting the trigger members 46 to the tubular member 29 is broken, thus, permitting the guide member 63 to fall free from the tubular casing 29 and due to its weight cause the beaded chain 61 with the sealant members mounted thereon to be withdrawn from the lower end of the tubular member 29.=

The sealant members 57 are elevated in the well casing in the same manner as described hereinbefore with respect to the transporter assembly shown in FIGURES 2 and 3 so that said sealant members will engage the perforations in the casing and be seated thereon for effecting a sealing of said perforations.

Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it is to beV understood that the specific terminology is not intended to be restrictive or confining, and that various rearrangements of parts and modifications of detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. Apparatus for temporarily sealing the perforations in the casing of a Well comprising a tubular member, means connected to said tubular member for raising and As shown in FIGURE 9,

lowering same in said casing, a carrying member, a plurality of sealant members, means detachably connecting said sealant members to said carrying member, said carrying member and sealant members positioned within said tubular member for lowering in said casing below said perforations, means connected to said carrying member for moving said carrying member and sealant members out of said tubular member in the vicinity of said perforations, said sealant members being drawn into engagement with said perforations by the How of uid from the casing through the perforations las the carrying member and ltubular member are being raised in the casing, the pressure of the fluid owing from the casing through the perforations being of sufficient magnitude to overcome the movement and force imparted to said sealant members by the raising of the carrying member to effect a separation of said sealant members from said carrying member.

2. Apparatus as set forth in claim 1 in which said sealant members are spherical balls .connected to the carrying member by breakable pliable suspension elements.

3. Apparatus for temporarily sealing the perforations in the casing of a well comprising -a carrying member positioned within the casing in the vicinity of the perforations, .a plurality of sealant members detachably connected to said carrying member by break-able elements, means connected to said carrying member for raising said carrying member in the casing and moving said sealant members through the perforated portion of the casing, said sealant members being drawn into engagement with said perforations by the ow of uid from the casing through the perforations contemporaneous with the raising of said carrying member in said casing, the pressure of the fluid flowing from the casing through the perforations being of suicient magnitude to overcome said breakable elements .and the movement and force imparted to said sealant members by the raising -of the carrying member to effect a separation of said sealant members from said carrying member.

4. Apparatus as set forth in claim 3 in which said breakable elements are strands of thread.

5. Apparatus as set forth in claim 3 in which said sealant members are spherical and formed of pliable material, and being of a size to seat on said perforations without being forced therethrough.

6. Apparatus for temporarily sealing the perforations in the casing of a well having uid owing from the casing through the perforations comprising an elongated tubular member, means connected to said tubular member for lowering .and raising same under positive control in said casing, a carrying member connected to and positioned Within said tubular member, a plurality of sealant members, means detachably connecting said sealant members to said carrying member -at spaced points along its length, a guide member connected to an end of said carrying member, means on said guide member detachably connected to said tubular member to hold said carrying member and sealant members within said tubul-ar member during the lowering of said tubular member to the area of the perforations, said means on said guide member engaging said casing as said tubular member is initially raised in said casing to detach said guide member from said tubular member and withdraw the carrying member and sealant members from said tubular member to a position below the perforations in the casing, said sealant members being drawn from the carrying stem and seating upon the perforations for sealing same by the uid owing from the casing through the perforations contemporaneous with moving the carrying stem through the perforated area as the tubular member is being raised in the casing, the pressure of the uid owing from the casing through the perforations being of suicient magnitude to overcome the movement and force imparted to said sealant members by the l0 raising of the tubular' member t effect a separation of said sealant members from said carrying stem.

7. Apparatus as set forth in claim 6 in which said sealant members are of pear shape 'and a size to close said perforations.

8. Apparatus as set forth in claim 6 in which said sealant members are ofl pear shape and have an outer covering of semi-exible material.

9. Apparatus as set forth in claim 6 in which said sealant members are of pear shape and `formed from a plastic material that is connected to said carrying member by strands of nylon material.

10. Apparatus as set forth in claim 6 in which said sealant members are spherical and formed of pliable material and being of -a size to seat on said perforations wtihout being forced therethrough.

11. Apparatus as set forth in claim 6 in which said carrying member is a-chain having one end connected to said tubular member and being of a greater length than said tubular member.

12. Apparatus as set forth in claim 6 in which said guide member is .a tapered plug of suiicient weight to effect the withdrawal of the carrying member and sea-laut members from the tubular member.

13. Apparatus as set forth in claim 6 in which said sealant members are relatively flat .and elongated and of a size to close splits and the like in the perforated casing.

14. The method of temporarily sealing the perforations in the casing of a Well which comprises lowering under positive control to a point adjacent the perfonations la tubular member containing a carrying member with a plurality of sealant members connected thereto, ejecting the carrying member and sealant members from the tubular member to a level below the perforations while maintaining said carrying member and sealant members from the tubular member to a level below the performations while maintaining said carrying member and sealant member under positive control and in suspension from said tubular member, elevating said tubular member and moving said carrying member and sealant members through the perforated area of the casing contemporaneous with circulating uid from the casing outwardly through the perforations to move the sealant members into engagement with the perforations while separating the sealant members from the carrying member.

15. A method in vaccordance with claim 14 wherein the sealant members are pear shaped.

16. A method in accordance with claim 14 wherein the sealant members are pear shaped and formed with an outer layer of pliable material.

17. A method in accordance With claim 14 wherein the sealant members are formed of a plastic material.

18. The method of temporarily sealing the perforations in the casing of a well which comprises lowering under positive control to a point below the perforations a member having a plurality of sealant members detachably connected thereto Iand depending therefrom, elevating the carrying member and moving the sealant members through the perforated area of the casing while flowing a fluid from the casing through the perforations to move the sealant members into engagement with the perforations for closing same while separating the sealant members from the carrying member.

19. Apparatus for temporarily sealing the perforations in the casing of a well comprising an elongated tubular member, a telescopic rod assembly mounted therein, a carrying member connected to said rod assembly for movement -into and out of said tubular member, a plurality of sealant members connected to said carrying member within said tubular member by pliable breakable elements, a guide member connected to an end of said carrying member, means connected to said tubular member for lowering same in the vicinity of the perforations, means carried by said guide member and detachably connected to said tubular members, said means engaging said casing to disconnect the guide member from the tubular member and enable said carrying member to be projected from the tubular member to place said sealant members adjacent the perforations contemporaneous with the raising of said tubular member by said rst mentioned means.

20. Apparatus for temporarily sealing the perforations in the casing of a well having iluid owing from the casing through the perforations comprising an elongated tubular member, a carrying member mounted within said tubular member and arranged to project from an end of said tubular member, a plurality of sealant members connected by brea-kable strand elements to said carrying member for positioning within said tubular member, means connected to the other end of said tubular member for lowering same in the vicinity of said perforations, telescopic means rconnected to said tubular member for projecting said carrying member and sealant members from said tubular member to a point below the perforaltions in the casing, spring members mounted on said tubular member and engageable with said casing for position` ing said tubular member in said casing, said sealant members engaging said perforations upon the raising of the tubular member by said first mentioned means contemporaneous with the breaking of said strand elements.

References Cited by the Examiner UNITED STATES PATENTS CHARLES E. OCONNELL, Primary Examiner.

JACOB L. NACKENOFF, Examiner.

20 s. J. NovosAD, Assistant Examiner.

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3384175 *Jun 9, 1966May 21, 1968Dow Chemical CoMethod of plugging wellbore casing perforations
US3437147 *Feb 23, 1967Apr 8, 1969Mobil Oil CorpMethod and apparatus for plugging well pipe perforations
US4139060 *Nov 14, 1977Feb 13, 1979Exxon Production Research CompanySelective wellbore isolation using buoyant ball sealers
US4187909 *Nov 16, 1977Feb 12, 1980Exxon Production Research CompanyMethod and apparatus for placing buoyant ball sealers
US4194561 *Nov 16, 1977Mar 25, 1980Exxon Production Research CompanyPlacement apparatus and method for low density ball sealers
US4195690 *Aug 14, 1978Apr 1, 1980Exxon Production Research CompanyMethod for placing ball sealers onto casing perforations
US20120067447 *Apr 16, 2010Mar 22, 2012Nicholas John RyanDelivery method and compositions
DE2838552A1 *Sep 4, 1978Mar 8, 1979Exxon Production Research CoVerfahren und vorrichtung zur fluessigkeitsbehandlung von bohrloecher umgebende unterirdischen formationen
DE2848972A1 *Nov 11, 1978May 17, 1979Exxon Production Research CoVerfahren zur selektiven behandlung unterirdischer formationen
Classifications
U.S. Classification166/284, 166/100, 166/165
International ClassificationE21B43/25, E21B43/26
Cooperative ClassificationE21B43/261
European ClassificationE21B43/26P