Apparatus And Method For Setting Liners In Well Casings

Abstract

An apparatus and method for setting a production liner within a well casing providing an elongated tubular setting sleeve adapted to be mounted on the upper end of such a liner and to be loosely received within the casing including tool means releasably connected to the sleeve for initially lowering the liner and the sleeve into the casing and expander means borne by said tool means effective radially to flare the sleeve into tightly sealing relation against the inner diameter of the casing to preclude the passage of sand and the like past the sleeve and into the liner.

Description

BACKGROUND OF THE INVENTION

Finely perforated tubular liners are usually disposed within the casings of oil wells and the like closely adjacent to the bottoms of the wells to serve as strainers against the passage of sand and other extraneous materials into the production fluid. The liners are substantially smaller in diameter than the casings to provide annular passages therebetween for the flow of production fluid radially into such liners and upwardly therethrough. Elongated strings of production tubing are subsequently disposed within the casings and have lower suction ends extended into the liners. On the upper ends of the liners are mounted tubular setting sleeves which are utilized supportably and releasably to connect the liners to the lower ends of their production tubing strings or drill strings or the like for lowering the liners into the casings. The lower ends of the liners are rested upon the bottoms of the wells and the installing tubing strings are disconnected from the liners and pulled from the well casings for the subsequent installation of the described production tubing into the wells.

The setting sleeve conventionally carries a lead, brass or neoprene seal ring which is intended sealably to engage the inner diameter of the casing. Such seal rings are employed for the purpose of attempting to preclude the passage of sand and other extraneous materials upwardly past the setting sleeve and thence downwardly into the upper open end of the liner to mix with the production fluid. The seal ring initially has an outside diameter at least equal to or slightly larger than the inside diameter of the casing. Consequently, during installation of the liner, the seal ring is compressibly forced into the casing and is slid downwardly the full length of the casing until the liner is disposed in its desired position at the bottom of the well. After such forced travel downwardly through the casing, the peripheral sealing surface of the seal ring is frequently entirely lost, particularly when the inner wall of the casing is roughened by cement deposits, scale and the like or the sections of the casing are angularly misaligned, kinked, out of round, or otherwise damaged, making sliding movement of the seal therein extremely difficult and substantially impossible in some instances but which nearly always renders the seal ineffective for the intended purpose. Furthermore, the connection between the setting sleeve and the tubing string is particularly difficult to reestablish when it is desired subsequently to retrieve the liner from the well.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide an improved apparatus and method for setting liners in well casings.

Another object is to provide such an improved apparatus and method which affords substantially unrestricted installation of a liner in a well casing.

Another object is to provide an apparatus of the character described which is capable of being conveniently manipulated to afford an effective metal-to-metal seal between it and the casing substantially to preclude the passage of sand and other extraneous material therepast and into the liner.

Another object is to provide an apparatus for setting liners in well casings which is readily disconnectable from the installing tubing string by convenient manipulation of the tubing string from the surface of the well.

Another object is to provide such an improved apparatus capable of automatically centering and freely accommodating the passage of other production equipment downwardly therethrough and into the liner.

Another object is to provide such an improved apparatus which permits the installing tubing string to be relatively quickly and conveniently recoupled for subsequent retrieval of the liner from the casing.

Another object is to provide such an improved apparatus which utilizes a tubular setting sleeve of integral one-piece construction which eliminates the separate seal rings of conventional liner setting devices.

Another object is to provide such an improved apparatus and method in which the setting sleeve has a contracted flanged portion of a diameter substantially less than the inside diameter of the casing during installation which is adapted subsequently to be radially flared in tightly sealing relation to the casing.

Another object is to provide such an improved apparatus which utilizes a liner setting sleeve in combination with a flaring tool manipulated by the installing tubing string which, after use, is readily disconnected from the setting sleeve and removed from the casing along with the tubing string.

Other objects and advantages of the present invention will subsequently become more clearly apparent upon reference to the following description and accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a central vertical section through a well bore and casing showing a liner setting sleeve and tool embodying the principles of the present invention suspended from a tubing string within the casing.

FIG. 2 is a fragmentary central section through the casing showing the setting sleeve in an expanded sealing position.

FIG. 3 is an exploded perspective view of the setting sleeve and tool removed from the casing.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring more particularly to the drawing, a liner setting apparatus embodying the principles of the present invention, generally indicated by the reference numeral 10, is adapted to be disposed within an elongated tubular well casing 12 of a well bore 14 having a bottom 15. An elongated tubular liner 20 is adapted to be lowered into the well casing by the liner setting apparatus 10 with the liner being of a substantially smaller diameter than the inside diameter of the casing to provide an elongated annular passage 22 therebetween. The liner has a lower end 23 which is adapted to be rested upon the bottom 15 of the well bore 14, an opposite upper internally screw-threaded end 24, and a plurality of relatively small slits or perforations 26 permitting the passage of production fluid from the well bore passage 22 into the liner.

The liner setting apparatus 10 of the present invention provides an elongated tubular setting sleeve 30 having a central annular body 32, an upper somewhat larger diameter sealing flange 33, and a somewhat reduced diameter lower connecting end 35 screw-threadably connected to the upper threaded end 24 of the liner 20. A plurality of relatively coarse left-handed screwthreads 37 are formed within the central body 32 of the setting sleeve for releasably connecting the sleeve to a setting tool generally indicated by the reference numeral 40.

The setting tool 40 of the liner setting apparatus 10 of the present invention includes an elongated arbor 42 which is substantially square in cross section and which provides predetermined upper and lower screw-threaded ends 44 and 45, respectively. As best shown in FIG. 3, a setting nut 47 having left-handed screwthreads corresponding to the threads of the body 32 and a substantially square opening 48 therethrough is slidably mounted on the arbor 42. A lower internally screw-threaded hanger coupling 49 is screw-threadably mounted on the lower end 45 of the arbor dependably to hold the setting nut and arbor in the described assembled condition.

A substantially circular flaring plate 50 having a centrally disposed substantially square opening 52 therethrough is axially slidably mounted on the upper end 44 of the arbor 42 above the setting nut 47. The flaring plate has an annular downwardly beveled surface 54 which is adapted to engage the upper edge of the sealing flange 33 of the setting sleeve 30.

An upper internally screw-threaded coupling 57 is adapted to be screw-threadably mounted on the upper end 44 of the arbor 42 in axially constraining relation to the flaring plate 50. The upper coupling is further adapted screw-threadably to connect the arbor 42 with the lower screw-threaded end 60 of an elongated tubing string 62 extended upwardly through the casing to the surface of the well bore 14. The tubing string represents any suitable support for lowering the liner setting apparatus 10 and the liner 20 into the well casing such as the conventional production tubing or drill strings employed in wells of this kind.

OPERATION

The operation of the described embodiment of the subject invention is believed to be readily apparent and is briefly summarized at this point. Prior to installation of the liner 20 within the well casing 12, the setting sleeve 30 is mounted on the upper end 24 of the liner. The components of the setting tool 40 are assembled, as shown in FIG. 3, prior to connection of the upper coupling 57 thereof to the lower end 60 of the tubing string 62. The setting nut 47 is screw-threadably disposed within the internally threaded body 32 of the setting sleeve by appropriate rotary manipulation of the arbor 42 by way of the driving connection provided by the square opening 48 within the setting nut. The upper coupling 57 is connected to the lower end 60 of the tubing string and the liner sleeve and setting tool are lowered downwardly within the casing 12. Such "running in" operation is easily accomplished with a minimum of difficulty and without any appreciable damage to the sealing flange 33 in view of the substantial clearance between the setting tool and the inside diameter of the casing. Since the sealing flange is disposed in its contracted position of FIG. 1 there is ample clearance to avoid most of the previously described restrictions to the passage of conventional liner setting devices downwardly within the casing.

During such downward movement of the liner setting apparatus 10, the liner 20, the setting sleeve 30 and the setting tool 40 are dependably supported on the lower hanger coupling 49 of the arbor 42. Upon engagement of the lower end 23 of the liner with the bottom 15 of the well bore 14, the weight of the liner and sleeve is relieved from the lower coupling 49 to permit relative axial movement between the arbor and the setting nut and sleeve. Further, during such downward travel of the liner within the casing, the flaring plate 50 of the setting tool 40 is gravitationally rested upon the upper edge of the sealing flange 33 of the setting sleeve 30.

In order to set the liner, the tubing string 62 is reciprocated from the surface of the well for repeated impact of the upper coupling 57 with the upper surface of the flaring plate 50. Upon such downward impact against the flaring plate, the beveled surface 54 thereof is effective uniformly radially outwardly to flare the flange 33 tightly against the inside diameter of the casing. Accordingly, a dependable metal-to-metal seal is provided between the flange 33 and the inside diameter of the casing positively to preclude the passage of sand or any other extraneous material upwardly through the passage 22 between the liner and the casing during subsequent operation of the well.

The setting tool 40 is relatively quickly and conveniently disconnectable from the setting sleeve 30 by appropriate rotation of the tubing string 62 for unscrewing the left-hand screwthreads on the setting nut 47 from the threads 37 of the setting sleeve. The setting tool is withdrawn upwardly through the casing and suitable production tubing extended downwardly within the well through the setting sleeve 30 and into the liner 20. It will be noted that during the installation of such production conduit or for the installation of any other production equipment such as pump bailers or the like, the flared sealing flange 33 provides an annular beveled entry surface for guiding such equipment in self-centering relation downwardly into the liner. In the event that it is desirable subsequently to pull the liner, the beveled entry surface of the sealing flange serves precisely to guide the setting nut 47 into immediate threading connection with the internal threads 37 within the body 32 of the sleeve. The left-hand threaded connection between the setting nut and the sleeve insures that the right-hand threaded connections between the upper coupling 57 and the lower end 60 of the tubing string are not loosened during the disconnection of the setting tool from the sleeve. If anything, the right-hand threaded connections of the coupling and the plurality of sections of the tubing string are further tightened by the right-hand turning action on the tubing string and the arbor 42 to effect such disconnection of the left-hand threads between the setting nut and sleeve. When, however, the liner 20 is employed with a cutting tool, not shown, at its lower end for a "drilling in" operation wherein the liner is employed as a drilling tool bit initially to form or to deepen the well bore 14, the right-hand threads may be employed between the setting nut and the sleeve.

In view of the foregoing, it is readily apparent that the structure of the present invention provides an improved liner setting apparatus and method for relatively quickly and conveniently installing perforated production liners within a well casing. The sealing flange 33 is conveniently expandable by manipulation of the setting tool 40 from the surface of the well dependably to provide an effective seal between it and the inside diameter of the casing. Such seal positively precludes the passage of sand and other extraneous material upwardly past the setting sleeve and thence downwardly within the liner where it would intermix with the production fluid being discharged upwardly from the well by way of the usual production tubing string. If it is desired to remove the liner from the well casing, the sealing flange 33 is merely milled off by a suitable cutting tool and the setting tool 40 reinstalled within the sleeve to afford a relatively quick coupling for the liner removing tubing string. As described, the liner setting sleeve affords an integral one-piece structure which eliminates the separate seal rings employed by conventional liner setting devices.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention.

Claims

We claim:

1. An apparatus for setting a production liner within a well casing upon the bottom of the well comprising an elongated tubular setting sleeve adapted to be mounted on the upper end of such a liner and to be loosely receivable within the casing, tool means releasably connected to said sleeve for initially lowering the liner and said sleeve into the casing, and expander means borne by said tool means which upon reciprocation of said tool means is effective to expand the sleeve against the casing in substantially tightly sealing relation to preclude the entry of sand and the like past the sleeve and into the liner.

2. The apparatus of claim 1 in which said sleeve provides an integral annular sealing flange having an initially contracted position substantially smaller than the casing for substantially unrestricted entry into the casing.

3. The apparatus of claim 2 in which said expander means includes a circular flaring plate having an annular beveled edge engageable with said sealing flange of the sleeve, and impact means on said tool means for bumping said flaring plate to expand the flange in flaring sealing relation to said casing.

4. The apparatus of claim 3 in which said setting sleeve has internally disposed screwthreads, said flaring plate has a centrally disposed square opening therethrough, tool means including a screw-threaded setting nut having a centrally disposed square opening therethrough adapted to be screw-threadably received within said setting sleeve, an elongated transversely square actuating arbor slidably extended through said openings in the plate and the nut and having predetermined upper and lower ends, a hanger coupling mounted on the lower end of the arbor for engagement with the nut in supporting relation to the sleeve and liner during entry into the casing, and an impact coupling on the upper end of the arbor for successive striking engagements against said flaring plate during reciprocation of said arbor relative to the sleeve, said arbor being rotatable to disengage said nut from the sleeve for removal of said tool means from the casing for the subsequent introduction of production equipment through the sleeve and into the liner.

5. The apparatus of claim 4 in which said flared sealing flange of the sleeve provides an annular tapered guide surface for automatically centering said production equipment within the casing during the entry of such equipment into the sleeve and liner.

6. The apparatus of claim 5 including an elongated tubing string having right-hand screw-threaded connection to said impact coupling, and said interengaging screwthreads of the sleeve and nut being left-handed to permit their separation and said removal of the tool means from said casing without disturbing said right-hand screw-threaded connection to said impact coupling of the tool means.

7. A method of setting a production liner within a well casing with the lower end of the liner rested upon the bottom of the well comprising the steps of mounting a setting sleeve on the upper end of the liner with the sleeve having a sealing flange initially disposed in a contracted position for substantially unrestricted downward insertion into said casing, connecting a combined liner supporting and flange flaring tool to said sleeve for initially lowering the liner and sleeve into the casing, reciprocating said tool to flare said flange on the sleeve radially outwardly in tightly sealing relation to said casing, and disconnecting said tool from the sleeve for removal of said tool from the casing and subsequent insertion of production equipment through the sleeve and into the liner with said sealing flange of the sleeve precluding entry of sand upwardly past the sleeve and into the liner.