US3463248A - Apparatus for discharging fluent substances into well bores - Google Patents

Description

ELL BORES W. T. BELL APPARATUS FOR DISCHARGING FLUENT SUBSTANCES INTO w Original Filed Nov. 6, 1967 4 Sheets-Sheet l U R e 0 w w W "a 5% w B 4 3 5 8 3 6 9 2 M Wu 0/ll 5 665 2 flu fl iw BRL WMMWW fi M II llll .l l l l I a G N O w A Y M A p w W \.i....:i::...l g 4 3 3 m 5G 5 4 E H 4 4 5H M 3 2 FIG. 7A

A118. 6, 1969 w. 1'. BELL 3,463,248

APPARATUS FOR DISOHARGING FLUENT SUBS'I'ANCES INTO WELL BORES Original Filed Nov. 6. 1967 4 Sheets-Sheet 2 FIG.3B

FIG. 3A

RQQR

William 7'. Bell INVENTOR.

avg/62E Z ATTORNEY s- 26. 9 w. T. BELL 3,463,248

APYARATUS FOR DISCHARGING FLUENT SUBSTANCES INTO WELL BORES Original Filed Nov. 6, 1967 l {Sheets-Sheet 5 William 1. Bell INVENTOR.

A TTORNEY Aug. 26, 1969 w. T. BELL 3,463,248

APPARATUS FOR DISCHARGING FLUENT SUBSTANCES INTO WELL BORES Original Filed NOV. 6, 1967' 4 Sheets-Sheet 4 FIG. 6

William T. Bell INVENTOR.

A TTORNE Y United States Patent 3,463,248 APPARATUS FOR DISCHARGING FLUENT SUB- STANCES INTO WELL BORES William T. Bell, Houston, Tex., assignor to Schlumberger Technology Corporation, New York, N.Y., a corporation of Texas Original application Nov. 6, 1967, Ser. No. 680,648. Divided and this application Oct. 23, 1968, Ser. No. 769,805

Int. Cl. E21b 43/119, 43/11, 33/138 U.S. Cl. 175-452 12 Claims ABSTRACT OF THE DISCLOSURE The particular apparatus described herein as illustrative of the invention are operative for replacing fluids in a selected interval of a well bore with suitable fluent substances. The various embodiments of apparatus of the invention described herein include a reservoir adapted to contain a fluent substance and a perforator for perforating earth formations adjacent to the selected well bore interval. Each of the disclosed tools are arranged so that selective movement of the perforator into the well bore interval is operative to induct well bore fluids into the reservoir as the fluent substance is discharged into the well bore interval around the perforator.

This application is a division of application Ser. No. 680,648, filed Nov. 6, 1967.

It is widely recognized that the entrance of well control fluids or so-called mud into newly formed perforations in an earth formation may, in time, plug the perforations so tightly that subsequent production of oil and/or gas from the formation will at least be impaired if not halted altogether. To counter this damage, suitable oilsoluble liquids and the like are commonly injected into the well bore at least in the vicinity of where perforations are to be made and a perforator is then actuated while these protective liquids are hopefully still in place. In this manner, it is believed that the soluble protective liquids will immediately rush into the perforations as they are made and block the subsequent entry of the well control fluids. Then, when connate fluids are produced through perforations protected in this manner, the produced fluids can easily flow into the well bore and wash away the soluble protective liquids.

Various proposals have been made heretofore for injecting such protective liquids around a perforator just before it is actuated to produce perforations at a desired location in a well bore. For one reason or another, however, these proposed techniques and devices have not been commercially accepted by the industry. For example, one tool proposed heretofore employs a self-contained pump that will supposedly pump a limited supply of protective liquids into the annulus around the perforator and completely displace the Well control fluids in this space into the well bore above an inflated packer on the tool. A similar previously proposed tool employs a source of high-pressure gas for discharging protective liquids around the perforator to displace the well control fluids upwardly away from the perforator.

It will be appreciated, however, that for the latter one of these tools to accomplish its intended function, the protective liquids must displace a significant volume of the well control fluids against the extreme hydrostatic pressure typically encountered in well bores. Moreover, with either of these techniques, there is no assurance that the protective liquids will not merely be diffused into the surrounding well control fluids rather than enveloping the perforator in a substantially homogeneous mass of the protective agent that will remain in position until "ice the perforator is actuated. Similar problems are also encountered where it is desired to perforate a formation interval and then inject a treating agent, such as acid or the like, to clean the perforations.

Accordingly, it is an object of the present invention to provide new and improved apparatus for reliably discharging a homogeneous mass of selected fluent substances into a selected well bore interval around a well perforator before it perforates earth formations adjacent thereto so that the fluent substances will enter the resulting perforations rather than being diluted by or being dispersed through other fluids in the well bore.

This and other objects of the present invention are accomplished by various embodiments of well-completion tools which, by selective movement, are each adapted to displace the well bore fluids around the tool and discharge a suitable treating agent into the resulting voided space upon such selective movement. By including a perforator with each of these tools, as the perforator is moved into the selected well bore interval, fluids in the well bore are removed from the space to be occupied by the perforator and simultaneously replaced with the fluent treating substance. Thus, upon actuation of the perforator, the treating substance will enter the resulting perforations into the adjacent earth formations without interference from the displaced well bore fluids.

The novel features of the present invention are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may be best understood by way of the following description of exemplary apparatus employing the principles of the invention as illustrated in the accompanying drawings, in which:

FIGURES 1A and 1B are cross-sectional views of the reservoir section of a completion tool arranged in accordance with the principles of the present invention;

FIGURE 2 is a cross-sectional view taken along thelines 22 in FIGURE 1B;

FIGURES 3A and 3B are views similar to FIGURES 1A and 1B but showing various elements thereof in their final position;

FIGURE 4 is a schematic representation of an alternative embodiment of a tool arranged in accordance with the present invention;

FIGURE 5 is an elevational cross-sectioned View of a portion of the completion tool shown in FIGURE 4; and

FIGURE 6 is a schematic view of still another completion tool incorporating the principles of the present invention.

Turning now to FIGURES 1A and 1B, the central portion of a Well-completion tool 10 arranged in accordance with the principles of the present invention is shown. As seen there, thetool 10 is comprised of anelongated housing 11 having anadapter head 12 connected to its upper end and adapted for coupling the housing to other tools (not shown) thereabove which preferably include a typical centralizer and a casing-collar locator such as that shown in Patent No. 3,114,876. The lower end of thehousing 11 is suitably adapted for connection to another tool centralizer (not shown) and a perforator (not shown). This perforator may, of course, be any one of the various types customarily employed in well-perforating operations. Although it is customary to fabricate well tools in a number of separable sections for ease of manufacture and assembly, various portions of thetool 10 are shown in the drawings as being integral with other portions so that minor constructional details of the tool will not affect an understanding of the invention.

In addition to the aforementioned perforator, thetool 10 includes areservoir 13 adapted to carry a supply of a suitable fluent substances; and means, such as aflow diverter 14, adapted to displace the fluent substance from the reservoir in response to movement of the perforator into a selected well bore interval. In the preferred embodiment of the present invention depicted in FIGURES 1A and 1B, the well-completion tool further includes a control section for selectively enabling thediverter 14 and the perforator upon command from the surface. The interrelation of these various elements 11-15 and the perforator therebelow will subsequently become more apparent.

Thereservoir 13 in the upper portion of thehousing 11 is formed by an enlargedlongitudinal bore 16 of uniform diameter extending an appropriate distance between theupper adapter head 12 and the upwardly facingshoulder 17 formed by the junction of the enlarged bore and a smallercoincidental bore 18 extending downwardly toward the lower end of the housing. Atubular conduit 19 is dependently secured and fluidly sealed to theadapter head 12 and extended downwardly along the central axis of thereservoir 13 to a position at least adjacent to theshoulder 17 for enclosing anelectrical conductor 20. Theelectrical conductor 20 is passed through atypical fluid seal 21 in theadapter head 12 and extended on upwardly through thetool 10 for appropriate connection to one or more conductors enclosed in a typical suspension cable (not shown).

Anannular piston member 22 is slidably disposed in theenlarged bore 16 and fluidly sealed therein by one or more external sealing members, as at 23, engaging thehousing 11 and an internal sealing member 24 engaging theconduit 19 to define upper end lowerenclosed spaces 25 and 26 in thereservoir 13. In its initial position shown in FIGURE 1A, thepiston member 22 is located as near as possible to theadapter head 12 to enable the lowerenclosed space 26 of thereservoir 13 to receive a maximum quantity of a treating agent (not shown). One or more lateral ports 27 (FIGURE 1A) are provided in the upper portion of thehousing 11 to admit well control fluids into the upperenclosed space 25 of thereservoir 13 as thetool 10 is being operated. Similarly, one or more normally closed ports 28 (FIGURE 1B) are provided in the lower portion of thehousing 12 and adapted, when open, for discharging a fluent substance from the lowerenclosed space 26 of thereservoir 13. Accordingly, as will subsequently be explained, once thelower ports 28 are opened and thetool 10 is operated so as to admit a flow of well control fluids into theupper ports 27, thepiston 22 will move downwardly in thereservoir 13 and displace a corresponding volume of the treating agent from thelower space 26 through the lower ports as the well control fluids enter the upper ports and fill theupper space 25.

To facilitate the movement of thetool 10 through a fluid-filled well bore to a starting position, thediverter 14 is initially retracted to provide suflicient clearance therearound between thehousing 11 and internal wall of the well casing (not shown). Similarly, although thepiston 22 will normally tend to remain in its elevated position within thebore 16 as shown in FIGURE 1A so long as thediverter 14 is retracted, it is preferred to keep theports 28 closed so that the fluent substance will not be lost from thelower space 26.

As shown in FIGURE 1B, thediverter 14 is preferably comprised of aflexible sleeve 29 of an elastomeric material that is secured at its upper end around the central portion of thehousing 11. The outer diameter of thehousing 11 is reduced just below the upper end of theelastomeric sleeve 29 and appropriately formed to provide longitudinally spacedexternal surfaces 30* and 31 that are separated from one another by anexternal surface 32 of a more-reduced diameter. Anelongated sleeve member 33 having an enlarged-diameterupper portion 34 is slidably mounted around the reduced central portion of thehousing 11 and fluidly sealed thereto by sealingmembers 35 and 36, respectively, encircling the spacedexternal surfaces 30 and 31.

Theelastomericdiverter sleeve 29 is disposed around a plurality of longitudinally extending, outwardly bowedflexible strips 37 that are circumferentially spaced around thehousing 11 and have their upper and lower ends secured betweenopposed shoulders 38 and 39 on the housing andenlarged portion 34 of theslidable sleeve member 33 respectively. The lower end of theelastomeric sleeve 39 is carried below the lower end of the bowedspring strips 37 and secured around theenlarged sleeve portion 34. To insure that the spring strips 37 will remain in the slightly bowed position depicted in FIGURE 1B, theenlarged portion 34 of theslidable sleeve member 33 is extended upwardly to about the middle of the spring strips and progressively enlarged so as to engage the rear surface of each strip and keep the central portions of the strips bowed outwardly.

It will be appreciated, therefore, that so long as theslidable sleeve member 33 remains in the position illustrated in FIGURE 1B, theelastomeric sleeve 29 will retain its generally relaxed position. By moving theslidable sleeve 33 upwardly in relation to thehousing 11, however, thesleeve shoulder 39 is moved toward thehousing shoulder 38 to shorten the distance between the opposite ends of the spring strips 37 and cause their central portions to bow radially outwardly. Thus, as theslidable sleeve member 33 is moved upwardly, the outward movement of the mid-portions of the spring strips 37 will radially expand the central portion of the elastomeric sleeve 29 a corresponding distance. Conversely, upon return of thesleeve member 33 downwardly, as the spring strips 37 relax, theelastomeric sleeve 29 will be restored to its original position.

Accordingly, it will be recognized that by releasably securing theslidable sleeve 33 in the position shown in FIGURE 1B, theelastomeric diverter sleeve 29 will be maintained in its fully retracted position and thetool 10 can be readily moved in a well bore with the well fluids therein freely bypassing the tool by way of the annular clearance around thediverter 14. To releasably secure thesleeve 33, one ormore ball members 40 are loosely confined inlateral openings 41 spaced around the lower portion of the slidable sleeve and adapted to be partially retained in aperipheral groove 42 around thehousing 11 by asecond sleeve member 43 that is telescoped over the slidable sleeve and releasably coupled to thehousing 11.

An inwardly projectinglug 44 on the retainingsleeve 43 is normally engaged with adog 45 disposed in ahousing recess 46 below the retaining sleeve and pivotally mounted therein on ashaft 47 journalled to thehousing 11. To retain the pivoteddog 45 in engagement with thelug 44, an electrically responsive detonator or so-calledexplosive squib 48 is adapted for abutting engagement with the dog to prevent it from rotating into a non-abutting position. Acompression spring 49 is arranged between opposed shoulders on thesleeves 33 and 43 to urge the retaining sleeve upwardly in relation to the slidable sleeve member once theexplosive squib 48 has freed thedog 45 for rotation.

Accordingly, once the retainingsleeve 43 is allowed to move upwardly in relation to theslidable sleeve 33, a diametrical enlargement within the retaining sleeve, such as provided by longitudinal grooves orslots 50 that are respectively longitudinally aligned with theballs 40, is moved into juxtaposition with the retaining balls. It will be appreciated, therefore, that by appropriately sizing the retainingballs 40 in relation to the annular clearances between the inner surface of theperipheral groove 42 and the inner surface of thesleeve 43, on the one hand, and the inner surface of theslots 50 on the other hand, the balls cannot be freed from the peripheral groove until the retainer sleeve has moved upwardly to 'bring the slots into registration with the balls.

By extending theretainer sleeve 43 upwardly and fluidly sealing it around theslidable sleeve 33 by sealingmembers 51 and 52 spaced above and below one ormore ports 53 in the slidable sleeve and approximately in registration with thelower housing ports 28, the retainer sleeve also serves as a valve that selectively blocks the flow of a treating agent from thelower space 26 until thesquib 48 is detonated and thediverter 14 is extended. Once, however, thesquib 48 is detonated and theretainer sleeve 43 is moved upwardly relative to theslidable sleeve 33 by thespring 49,lateral ports 54 in the retainer sleeve are brought into registration with thehousing ports 28 andports 53 in the slidable sleeve to allow the treating agent to be exhausted therethrough as thepiston 22 moves downwardly.

From the description of the tool to this point, it will be seen that once all of the various elements described so far are in their respective positions depicted in FIGURES 1A and 1B, thediverter 14 will be retained in its retracted position so long as theexplosive squib 48 is not detonated. When thesquib 48 in thecontrol section 15 is detonated, thespring 49 will urge theretainer sleeve 43 upwardly in relation to theslidable sleeve 33 which, at this time, is still secured to thehousing 11 by theretainer balls 40. Once, however, theretainer sleeve 43 moves a sufiicient distance upwardly to bring theslots 50 into registration with the outer surfaces of theballs 40, the combined force of acompression spring 55 carried between opposed shoulders on theslidable sleeve 33 and thehousing 11 and anothercompression spring 56 will cause the balls to be cammed out of thecircumferential groove 42 and into the enlarged annular space between the outer surface of thehousing 11 and the inner surfaces of theslots 50. Thespring 56 is engaged between afixed shoulder 57 on the slidingsleeve 33 and anabutment 58 releasably secured at this time to thehousing 11. The function of thismovable abutment 58 and the manner of securing it will be subsequently explained.

Accordingly, it will be appreciated that once theballs 40 are released from thecircumferential groove 42, the slidingsleeve 33 will be shifted upwardly by the combined force of thesprings 55 and 56 to begin bowing the spring strips 37 outwardly. Theretainer sleeve 43 is, of course, carried further upwardly by the slidingsleeve 33. It will be recognized, therefore, that thespring 49 will move theretainer sleeve 43 upwardly in relation to the slidingsleeve 33 to a position where theports 53 and 54 are in registration with one another. Thus, once the slidingsleeve 33 reaches its elevated position, thesleeve ports 53 and 54 will be in registration with thehousing ports 28. At this point, the bowedspring strips 37 will have been expanded outwardly a sufficient distance to bring theelastomeric sleeve 29 either very near to or into engagement with the inner wall of the casing. This will, therefore, block the annular space between thetool 10 and the casing.

Once thediverter 14 is fully expanded and theports 28 opened, it will be appreciated that upward movement of thetool 10 will force the well bore fluids through theports 27 at the upper end of thehousing 11 and into the upperenclosed space 25 therein. Thus, continued upward movement of thetool 10 will be effective to move thepiston 22 downwardly in relation to thehousing 11. As thepiston 22 moves downwardly, the treating agent in the lowerenclosed space 26 will, of course, be forced therefrom by way of thelower ports 28 and into the annulus between thetool 10 and well casing below the expandeddiverter 14 to envelop the perforator suspended below thereservoir 13.

When thepiston 22 nears the lower limit of its travel, a dependingtubular probe 59 thereon will engage the inwardly-projecting ends of a plurality ofinclined dogs 60 that are each carried in ahousing recess 61 on apivot pin 62 journalled to thehousing 11 and have their outwardly extending upper ends a'butted against the lower face of theabutment 58. Biasing means, such as reverselybent springs 63, are provided to normally maintain the upper ends of thedogs 60 extended in the position shown in FIGURE 1B to support theabutment 58 against the force of thespring 56.

As seen in FIGURES 3A and 3B, once the lower end of the dependingprobe 59 from thepiston 42 engages and passes the inwardly projecting lowe rends of the pivoteddogs 60, the dogs will be cammed to a generally erect position once the piston has reached theshoulder 17. Once thedogs 60 are pivoted into an upright position, the compressive force of thespring 56 will shift the slidingabutment 58 downwardly in relation to thesleeve member 33 until an inwardly projectingshoulder 64 thereon halts further travel of the abutment. With thespring 56 confined between theshoulders 57 and 64 on thesleeve member 33, thespring 56 will, of course, no longer be effective to urge the sleeve member upwardly in relation to thehousing 11 and only the force of thespring 55 will be maintaining the sleeve member in its elevated position. Although theelastomeric sleeve 29 is shown still extended in FIGURES 3A and 3B for purposes of illustrating that position, it will be recognized, of course, that once theabutment 58 is released, the spring strips 37 will begin expanding.

Accordingly, by selecting thespring 55 to have an effective spring force somewhat less than that required to bow the spring strips 37 outwardly against pressure forces act ing downwardly on thediverter 14, once thespring 56 is immobilized between theshoulders 57 and 64, the forces tending to straighten the bowed spring strips will be effective to return the sleeve member back to its initial position. It will be realized, however, that although thespring 55 must be appropriately selected to have a spring force which, when combined with that of thespring 56, will be sufiicient to bow the spring strips 37 outwardly in the previously described manner, thespring 55 by itself will not be sufiiciently strong to prevent relaxation of the spring strips once thespring 56 is immobilized. Thus, it will be appreciated that the function of the releasablysecured abutment 58 is to selectively enable and disable thespring 55 by initially maintaining thespring 56 in a first position aiding thespring 55 and then, once the abutment is released, allowing thespring 56 to move to a second position in which thespring 55 is no longer effective to maintain theelastomeric sleeve 29 in its extended position.

Return of theslidable sleeve 33 will, of course, carry theouter sleeve 43 back downwardly with little or no change in its position in relation to the slidable sleeve. It will also be noted from FIGURES 3A-3B that by providingports 65 in the upper end of thetubular probe 59, once the probe enters thebore 18 the remaining treating agent in the lowerenclosed space 26 of thereservoir 13 will continue flowing therefrom to allow thepiston 22 to move to a final position abutting theshoulder 17.

To selectively detonate theexplosive squib 48 from the surface without risking a premature actuation of the perforator, a so-called single-pole double-throw switch 66 (FIGURES 1B and 2) is mounted in thehousing recess 46 and adapted for movement between a first switching position electrically connecting theexplosive squib 48 to theconductor 20 and a second switching position electrically connecting theconductor 20 to the perforating devices (not shown) in the perforator therebelow. To accomplish this, theswitch 66 is provided with an actuator 67 that is normally engaged with a flat 68 formed on ashaft 69 that is journalled at its opposite ends to thehousing 11. Acrank arm 70 secured to theshaft 69 and extending laterally therefrom is provided with a bifurcated end portion orclevis 71 that is movably coupled, as by apin 72, to one end of anextension 73 dependingly secured from the lower end of thesleeve 33. In this manner, so long as theslidable sleeve member 33 remains in the position shown in FIGURES lA-lB, only theexplosive squib 48 will be electrically connected to theconductor 20.

7 Then, as seen in FIGURES 3A-3B, once thesleeve 33 is released, theswitch 66 will be operated to electrically connect theconductor 20 to the perforator mounted therebelow.

To employ thetool 10 in a well-completion operation, a suitable nonplugging liquid or some selected fluent treating substance of a similar or different nature is introduced into the lowerenclosed space 26 of thereservoir 13 as by a filling port that is then closed by aplug 74. Typical treating agents that may be used are acid, propping agents containing particulate solids of sand, metal, glass, plastic and the like as well as various cleaning agents, and suitable temporary plugging agents such as gelled kerosene, gelled carbon tetrachloride, or such commerically-available protective formulations as Black Magic sold by Oil Base, Inc., of Houston, Tex., or Plug Ban" as sold by Humble Oil and Refining Co. of Houston, Tex. Any suitable agent can be used, of course, so long as it does not react adversely :with formation materials and fluids and can be removed from a perforation when it is produced. It should also be noted that as far as thetool 10 is concerned, improved results will be obtained where the treating substance has a lower density than that of the well control fluids so that once it is injected into the well bore, the fluent substance will not tend to settle downwardly away from thediverter 14.

Once thereservoir 13 is filled and the other elements of thetool 10 are in their respective positions shown in FIG- URES lA-lB, the tool is suspended from a suitable cable (not shown) and lowered into a well bore to a position somewhat below the formation interval that is to be completed. Once thetool 10 is in position, electrical current is applied from a power source at the surface to the conductor to detonate theexplosive squib 48 and thetool 10 is raised to bring the perforator into position adjacent the formation interval to be perforated.

When thesquib 48 is detonated, the retainingsleeve 43 is moved upwardly by thespring 49 to free theballs 40 from thecircumferential groove 42 and release theslidable sleeve member 33. Once thesleeve 33 is released, the combined spring force of thesprings 55 and 56 will move the slidable sleeve member upwardly to extend thediverter 14 against the downwardly acting pressure forces thereon. Theouter sleeve 43 will have moved upwardly relative to theslidable sleeve 33 to bring theports 53 and 54 into registration so that, once the slidable sleeve member has moved upwardly a distance sufficient to extend the diverter, theports 53 and 54 will be in alignment with thehousing ports 28.

While thediverter 14 is being extended, thetool 10 is still being moved upwardly so that once theports 28, 53 and 54 are in alignment and the diverter is extended, the continued upward movement of the tool will divert the well bore fluids above the expandedelastomeric sleeve 29 through theupper housing ports 27 and into theupper reservoir space 25. As the well bore fluids are diverted into theupper reservoir space 25, thepiston 22 will be moved downwardly in relation to thehousing 11 to discharge whatever fluent substance there is in thelower reservoir space 26 through thelower housing ports 28 and into the well bore below theelastomeric sleeve 29.

It will be recognized that the treating agent being expelled into the well bore is moving into the annulus from which the well bore fluid entering the upper enclosed space has just been displaced by the swabbing action of thediverter 14 resulting from the upward movement of thetool 10. Thus, there will be little or no chance that the treating agent will be dispersed into the well bore fluids. In this manner, the continued upward travel of thetool 10 will insure that a substantially homogeneous mass of the fluent substance will simultaneously envelop the lower portion of thetool 10 below thediverter 14. Accordingly, by the time that the perforator on thetool 10 has been moved into a position adjacent the formation interval to be perforated, the perforator will be completely enveloped by a homogeneous mass of the selected treating agent.

Once it is determined that the perforator is correctly positioned, electrical current is applied from a power source at the surface to the suspension cable to actuate the perforator. It will be recalled that the release of the retainingsleeve 43 will have actuated theswitch 66 to connect the perforator to theconductor 20. Although thetool 10 can be halted before the perforator is actuated, it is preferred to continue moving the perforator upwardly as it is actuated to insure that the last portion of the treating agent is expelled from the reservoir 13 a short time after the well bore is perforated. It will be appreciated, of course, that the position of the perforator in relation to the formation interval being completed will be known at all times by virtue of typical depth indiactors at the surface whose accuracy is confirmed by depth-correlation devices on thetool 10 such as the aforementioned casingcollar locator.

The effective volume of thereservoir 13 must, of course, be determined to insure that when the perforator is actuated, it is completely surrounded by the fluent substance. Moreover, where an enclosed retrievable carrier perforator is employed, the effective volume of thereservoir 13 should be suflicient to accommodate the volume of the fluent substance that will fill the carrier once it is perforated. In a typical arrangement of thetool 10 where an enclosed retrievable carrier perforator is used, the effective length of the lowerenclosed space 26 will accordingly be in the order of about 1.5 to 2.0 times the length of the carrier. With relative proportions of this order, a continuing discharge of the fluent substance will be obtained as thetool 10 is moved further upwardly after the perforator is actuated.

Once thepiston 22 reaches the lower limit of its travel as determined by theshoulder 17, thetubular probe 59 thereon will have actuated the pivotedlatch fingers 60 to release themovable abutment 58 and disable thespring 55. Once thespring 55 is disabled, theelastomeric sleeve 29 will be restored to its retracted position and well bore fluids can again freely bypass thetool 10 as the tool is returned to the surface.

Turning now to FIGURE 4, a somewhat schematic view is shown of asecond completion tool 200 which is also arranged in accordance with the principles of the present invention. As seen there, thetool 200 is suspended from acable 201 in a cased well bore 202 just above anearth formation 203 which is to be completed. Thecompletion tool 200 preferably includes one or moretypical centralizers 204 and 205 longitudinally spaced along the tool to maintain it centered in the well bore 202 as well as some means, such as a casing-collar locator 206, for determining the depth of the tool. Atypical well perforator 207, such as anenclosed carrier 208 with one or more perforating devices or shapedcharges 209 therein, is coupled below thecollar locator 206 and electrically connected to thesuspension cable 201 in such a manner that the perforator can be selectively actuated upon command from the surface. The lower portion of thetool 200 is comprised of a selectively actuatedfluid diverter 210 and areservoir 211 adapted to contain a fluent substance for carrying out the particular completion operation.

As best seen in FIGURE 5; thefluid diverter 210 is preferably arranged in a similar fashion to thetool 10 previously described. Accordingly, as will be seen from a comparison of FIGURES lA-lB with FIGURE 5, thefluid diverter 210 includes anelastomeric sleeve 212 that is releasably secured in a relaxed position by asleeve 213 slidably mounted around thetool body 214. Theslidable sleeve 213 is held in an elevated position on thebody 214 by one or more retainingballs 215 that are loosely disposed in lateral openings in the sleeve and are normally retained in acircumferential groove 216 by anouter sleeve 217 slidably mounted around the upper portion of theinner sleeve 213. An electrically responsive release,

such as an explosive squib 218 engaging a pivotedlatch 219, is employed to prevent aspring 220 mounted between opposed shoulders on thesleeves 213 and 217 from moving the outer sleeve downwardly in relation to the inner sleeve until the squib is detonated upon command from the surface.

Once theouter sleeve 217 is released and has moved downwardly a suflicient distance to allow theballs 215 to move outwardly intolongitudinal slots 221 in the outer sleeve, theinner sleeve 213 will be urged downwardly by acompression spring 222 retained betweenopposed shoulders 223 and 224 on thebody 214 and inner sleeve respectively. Once theinner sleeve 213 begins moving downwardly in relation to thebody 214, the spring force of thespring 222 will be suflicient to bow a plurality of circumferentially spaced, longitudinal spring strips 225 that are confined within theelastomeric sleeve 212 and have their opposite ends engaged withopposed shoulders 226 and 227 on thetool body 214 andinner sleeve 213, respectively. Thus, downward movement of theinner sleeve 213 will cause theelastomeric sleeve 212 to be expanded outwardly a sufficient distance to at least approach the inner surface of the well casing.

It will also be appreciated that the initial downward movement of theouter sleeve 217 by thespring 220 will bring one ormore ports 228 in the sleeve into alignment with a corresponding number ofports 229 in theinner sleeve 213. Then, as theinner sleeve 213 is subsequently moved downwardly by thespring 222 and carries theouter sleeve 217 along with it, theports 228 and 229 will be brought into registration with a plurality ofports 230 in the upper portion of thetool body 214. Once theports 230 are uncovered, the upper end of alongitudinal bore 231 in thetool body 214 forming the upper end of thereservoir 211 is opened. Thus, once theelastomeric sleeve 212 is expanded and theports 230 uncovered, downward movement of thetool 200 through the well bore 202 will force the well borefluids 232 into a plurality ofports 233 in the upper end of thereservoir 211 to displace the treatingagent 234 upwardly from thereservoir 211 and expel the agent through theports 230 into the well bore 202 above thediverter 210. To insure that the treatingagent 234 is displaced from thereservoir 211, atubular member 235 is connected to thetool body 212 at the lower end of thebore 231 and extended downwardly therefrom to about the bottom of the reservoir.

Accordingly, to employ thetool 200, a selected treating substance is disposed in thereservoir 211. Although this substance may be one of those previously described, it is preferred that this substance have a density somewhat greater than the density of the well borefluids 232 to insure that the treating agent will remain as a homogeneous mass in the well bore 202 just above the expandeddiverter 210.

Once thetool 200 has been brought into position just above the selectedformation 203, the explosive squib 218 is detonated to expand theelastomeric sleeve 212 and open theports 230. Thus, as thetool 200 is lowered further into the well bore 202, the Well borefluids 232 will be forced into theports 233 to expel the treatingagent 234 out of theports 230 and envelop the annular clearance around the tool. Then, once thetool 200 has been lowered a suflicient distance to bring theperforator 207 into position opposite theformation 203, the perforator will be completely surrounded by the treatingsubstance 234 and, upon detonation of the shapedcharges 209, only the treating substance can enter the resulting perforations into the formation.

Thetool 200 is simply raised to retrieve it to the surface following the actuation of theperforator 207. It will be recognized, of course, that the expandeddiverter 210 will not materially hamper retrieval of thetool 200 since the well borefluids 232 will pass freely through the tool by way of theports 230 and 233 since they are interconnected by thetubular extension 235 and thebore 231.

Turning now to FIGURE 6, anothercompletion tool 300 is shown in a cased well bore 301 suspended from acable 302 and maintained in the center of the well bore 301 by atypical centralizer 303 mounted on the upper portion of the tool. A casing-collar locator 304 is also preferably included with thetool 300 for providing indications at the surface of the position of the tool in relation to an earth formation, as at 305, to be completed.

Thecompletion tool 300 is comprised of areservoir section 306 having afluid diverter 307 and ananchor 308 mounted thereon. Atypical perforator 309 dependently secured below thereservoir section 306 is provided with one or more perforating devices, such asshaped charges 310, that may be selectively actuated upon command from the surface. If desired, another centralizer (not shown) similar to thecentralizer 303 may be arranged on theperforator 309 to assure that the perforator is centrally located in thewell bore 301.

Thereservoir section 306 is comprised of an outertubular housing 311 that is slidably telescoped around an elongated axialtubular member 312 dependently coupled, as by anadapter 313, to the upper portion of thetool 300 and connected, as by another adapted 314, to the upper end of theperforator 309. The upper portion of thetubular housing 311 is reduced in diameter, as at 315, and provided with a fluid seal, such as an O-ring 316, to slidably seal the upper end of the housing in relation to the dependingtubular supporting member 312. The central portion of thetubular support 312 is enlarged in diameter, as at 317, and provided with afluid seal 318 that is slidably engaged with the inner wall of thetubular housing 311 so as to define anenclosed space 319 within the housing between the reduced upper end 315 thereof and the enlarged portion of the depending support member.

A somewhat largertubular member 320 is dependently secured to the enlargedcentral portion 317 of the elongatedtubular support 312 and coaxially extended downwardly around the lower portion of the support to about the upper end of theperforator 309. Apassage 321 through the enlarged-diameter portion 317 is adapted to provide fluid communication from the enclosedspace 31 9 to theannular space 322 between the dependingsupport 312 and thetubular member 320. Selectively-operable valve means, such as an explosivelyactuated valve 323, are provided to normally close thepassage 321 and retain a treatingagent 324 in theenclosed space 319 until the valve is actuated upon command from the surface. It will be appreciated that theaxial passage 325 will permit suitable electrical conductors (not shown) to be passed from the upper portion of thetool 300 to thevalve 323 andperforator 309.

Thediverter 307 is comprised of one or moreannular discs 326 of a thin, flexible material, such as may be cut from an elastomeric sheet, that are secured around the lower portion of thehousing 311 and suitably sized to engage the inner walls of the cased well bore 301. It will be appreciated, however, that passage of thetool 300* through the well bore 301 will not be unduly hampered inasmuch as the well borefluids 327 can readily pass around theflexible discs 326.

For reasons that will subsequenty become apparent, theanchor 308 is adapted to frictionally engage the innor walls of the cased well bore 301 with a force greater than the restraining force provided by thecentralizer 303 and any centralizer (not shown) mounted on theperforator 309. The restraining force provided by theanchor 308 is not so great, however, that the combi'rEd weight of thetool 300 will not carry the tool on downwardly into the well bore 301 as thecable 302 is unspooled from the surface. Theanchor 308 is typically comprised of a number of sol-called drag-blocks or bowedspring strips 328 arranged in the usual fashion.

Accordingly, once theenclosed space 319 is filled with the treatingagent 324, it will be recognized that as thesuspension cable 302 is unspooled at the surface, thetool 300 will descend into thewell bore 301. As thetool 300 descends, theflexible elas'tomeric diverter 307 will deflect as necessary to allow the well borefluids 327 to pass around the tool. It will be appreciated that so long as thevalve 323 remains closed, thefluent substance 324 in thereservoir space 319 will retain thehousing 311 andsupport member 312 in the positions illustrated and prevent their relative movement. Once thecollar locator 304 indicates that thetool 300 is so located with respect to theformation 305 that the lower end of thereservoir 306 is about even with the upper limit of the formation interval and the upper end of theperforator 309 is about even with the lower limit, the tool is halted.

Then thetool 300 is selectively enabled by opening the explosively actuatedvalve 323. Once thevalve 323 is opened, upward movement of thesuspension cable 302 will be effective to displace the treatingagent 324 from thereservoir space 319 as thecentral support 312 and its enlarged portion 315 are moved upwardly in relation to thehousing 311 which is now held stationary by theanchor 308. As the treatingagent 324 is discharged through thepassage 321 andannular clearance 322, thewell fluids 327 will, of course, fill the void below theenlarged portion 317 as it is moved upwardly into thenowstationary housing 311. Thus, thewell fluids 327 in that portion of the well bore 301 below theelas'tomeric diverter 307 will be drawn upwardly into thereservoir housing 311 as these fluids are replaced by the treatingagent 324. By extending thetubular member 320 to near the upper end of theperforator 309, the perforator will be progressively enveloped in a homogeneous mass of thefluent substance 324 as the perforator is brought upwardly into position. It will be recognized that by selecting thefluent substances 324 to have a lower density than that of thewell fluids 327, thediverter 307 will keep the substances from moving on up the well bore.

As a result, once theperforator 300 is at the upper limit of its travel (as determined by the collar locator and other typical depth-measuring devices at the surface), the movement of thecable 302 is halted. Theperforator 309 is at this time completely surrounded by thefluent substance 324 so that when the perforator is actuated, only the fluent substance can enter the resulting perforations (not shown). Thetool 300 is then simply withdrawn.

As described above, thetool 300 is arranged so that when theperforator 309 is at its upper limit of travel and is in position for actuation, the upper end of the perforator is somewhat below the lower end of thereservoir housing 311. It will be appreciated, however, that thetool 300 could also be so arranged that theperforator 309 would enter the lower open end of thereservoir housing 311 and be at least partially received by thereservoir 306 when the shapedcharges 310 are detonated. This would, of course, require that thehousing 311 either be expendable or have appropriately located replaceable wall portions through which the perforating jets. would pass. The advantage of this alternative arrangement would be that the overall length of this alternate tool would be reduced by a significant amount.

Accordingly, it will be appreciated that the present invention has provided new and improved apparatus by which a well bore can be perforated to allow only selected fluent substances to enter the perforations. It is quite apparent, therefore, that the present invention will enable a homogeneous mass of a selected substance to envelop a perforator before it is actuated so that only the substance will contact the formations when they are perforated. It should be realized, of course, that these fluiddisplacement tools are also suitable for use either alone or with other well tools aside from a perforator.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects; and, therefore, the

12 aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. A well-completion tool adapted to be supported by a suspension member in a well bore containing fluids and comprising: a reservoir adapted to contain fluent substances; first means adapted to isolate a selected interval of such a well bore; second means operable upon movement of such a suspension member supporting said well-completion tool for simultaneously withdrawing well bore fluids from around said well-completion tool into said reservoir and discharging fluent substances contained therein into such an isolated interval; and perforating means on said well-completion tool and adapted to be moved into fluent substances discharged into such an isolated interval in response to movement of such a suspension member for operation of said second means.

2. The well-completion tool of claim 1 wherein said movement-responsive means include: first and second passage means respectively providing communication between first and second spaced portions of said reservoir and spaced locations on the exterior of said tool; and means normally blocking communication through said first passage means and adapted for opening such communication in response to a command from the surface.

3. The well-completion tool ofclaim 2 wherein said movement-responsive means further include: piston means movably disposed in said reservoir for isolating said first and second reservior portions from one another.

4. The well-completion tool ofclaim 2 wherein said movement-responsive means further includes: an elongated member extending through said reservoir and adapted for connection at its upper end to a suspension member; piston means on an intermediate portion of said elongated member and slidably sealed within said reservoir for isolating said first and second reservoir portions from one another; means slidably sealing said reservoir to said elongated member between said piston means and one of said ends of said elongated member for enclosing a fluent substance in said one reservoir portion; and means for securing said reservoir against movement in relation to a well bore whenever said passageblocking means are opened so that said elongated member can be moved in relation to said reservoir to shift said piston means toward said sealing means.

5. A well-completion tool adapted for suspension from a cable in a well bore containing fluids and traversing an earth formation to be completed, comprising: a body having an internal chamber adapted to contain a fluent substance; means in said chamber dividing said chamber into first and second portions; first and second passage means respectively providing fluid communication between said first and second chamber portions and first and second spaced exterior locations on said body; and flow-diverting means mounted around said body between said spaced exterior locations and responsive to movement of said tool into an interval of a well bore for diverting well bore fluids from that interval into said first passage means to displace a fluent substance contained in said chamber from said second passage means and into that interval.

6. The well-completion tool ofclaim 5 wherein: said chamber-dividing means include a piston sealingly disposed in said chamber and movable in response to entrance of well bore fluids into said first chamber portion on one side of said piston to displace a fluent substance confined in said second chamber portion on the other side of said piston through said second passage means into that well bore interval.

7. The well-completion tool of claim 6 further including: a well perforator connected adjacent to said second exterior location and adapted forselective actuation 13 from the the surface for perforating an earth formation adjacent such a well bore interval.

8. The well-completion tool ofclaim 5 wherein: said chamber-dividing means comprise a transverse partition across said chamber between said first and second chamber portions, and a tubular member extending into said first chamber portion and providing fluid communication between said chamber portions.

9. The well-completion tool of claim 8 further including: a well perforator connected adjacent to said Second exterior location and adapted for selective actuation from the surface for perforating an earth formation adjacent such a well bore interval.

10. A Well-completion tool comprising: perforating means adapted for suspension in a well bore containing fluids; a reservoir adapted to contain a fluent substance; and means responsive to movement of said perforating means into a selected interval of such a well bore for simultaneously withdrawing fluids from such a selected interval into said reservoir and discharging a fluent substance from said reservoir into such a selected interval around said perforating means.

11. A well-completion tool adapted for suspension from a cable in a well bore containing fluid and traversing an earth formation to be completed, comprising: a tubular body having an internal longitudinal bore; an elongated member extending through said internal bore of said tubular body and having first means on its upper end adapted for connection to a suspension cable and second means on its lower end adapted for connection to a well perforator; piston means on said elongated member fluidly sealed within said internal bore and adapted for movement in relation to said tubular body from a first lower position to a second upper position relative thereto; sealing means fluidly scaling to upper portion of said tubular 'body to said elongated member for defining an enclosed chamber in said internal bore above said piston means; selectively operable passage means normally blocking fluid communication from said enclosed chamber and adapted for opening upon command from the surface; and wall-engaging means on said tubular body adapted to secure said body a Well bore wall whenever said selectively operable passage means are opened.

12. The well-completion tool ofclaim 11 further including: a well perforator connected to said second connection means and adapted for selective actuation from the surface.

References Cited UNITED STATES PATENTS 2,934,146 4/1960 Laval 166110 X 3,097,698 7/ 1963 Corley et al 166-23 X 3,118,503 1/1964 Rike et al. 166162 3,138,206 6/1964 Bruce et al 166-35 X 3,212,576 10/1965 Lanmon 166100 X 3,379,251 4/1968 Bohn 16623 DAVID H. BROWN, Primary Examiner US. Cl. X.R. 166-55.1, 162

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