Abstract:
A method and apparatus for installing in a well conduit by a single trip on an auxiliary conduit a combination well condition sensing device and flow cut off valving elements. The cooperating valving elements are of annular configuration and the auxiliary conduit passes through the bore of the valving elements and is mechanically connected to one of the valving elements. The entire apparatus may be run into the well conduit in a single trip on the auxiliary conduit and actuated to a flow shut off position by longitudinal manipulation of the apparatus. Pressurization of the upper well conduit and secondary manipulation of the apparatus and the auxiliary conduit permits the return of the valving elements to an open flow position.

Description:
BACKGROUND OF THE INVENTION 
     l. Field of the Invention 
     The invention relates to a combination flow shut off valve and well condition sensing device for downhole installation in a well conduit immediate to a producing zone. 
     2. Description of the Prior Art. 
     In the completion of oil or gas wells, it is essential that accurate measurements be taken of various parameters involved in the production zone, such as fluid pressure and temperature. Experience has shown that more reliable measurements are obtained when the condition sensing device is positioned closely adjacent the producing zone and upward flow of produced fluids is entirely shut off. Additionally, certain important operating parameters are best determined by measurements taken first after a flow shut off, then re-opening the shut off valve to permit fluid flow, then shutting off the flow and taking an additional set of measurements. 
     Downhole shut off valves have heretofore been utilized but have been characterized by relatively complex structures requiring a plurality of trips into the well to install and a plurality of trips to remove from the well at the completion of the tests. There is, therefore, a distinct need for a downhole shut off valve operable in conjunction with a condition sensing device which can be installed in a single trip of an auxiliary conduit into the well. Where the sensing device is electric, it would be highly advantageous to accomplish the run-in and flow shut off with an electric wire line. 
     SUMMARY OF THE INVENTION 
     The invention provides a method of installing and operating a well condition sensing device, and an improved valving apparatus incorporating a well condition sensing device which can be installed in the wall with a single trip of an auxiliary conduit and operated by such auxiliary conduit. The fluid flow cut off apparatus is defined by a tubular outer body assembly within which a hollow mandrel is axially slidably mounted. An external annular elastomeric seal is provided on the tubular outer body to cooperate with a seal bore provided in the well tubing at a point immediately above a production zone. Such elastomeric seal is normally not in sealable contact with the seal bore but can be compressibly expanded to effect a sealing engagement with the seal bore by upward movement of the mandrel. Additionally, an internal annular seal bore or valve seat is provided in the outer body which is engaged by an annular seal on the hollow mandrel when it is moved to an upper position relative to the tubular body. Thus fluid flow around or through the tubular outer body is cut off. 
     Typically, an electric well condition sensing device is mounted in the bore of the hollow mandrel and an electric wire line traverses the bores of the tubular outer body and is mechanically connected to the hollow mandrel and electrically connected to the electric well condition sensing device. The entire valving and sending apparatus is run into the well. on the electric wire line and, after being positioned in the well conduit at a point above the production zone through the operation of conventional radially shiftable lock elements, or by other similar and known means, the application of tension to the electric wire line will produce an upward movement of the hollow mandrel which will concurrently expand the external annular elastomeric seal on the tubular body assembly into engagement with the adjacent seal bore on the well conduit, such as a landing profile nipple, and effect a sealing engagement of the annular seal on the mandrel with the seal bore or valve seat. 
     Preferably, a compressed helical spring is mounted between the tubular body assembly and the hollow mandrel to urge the hollow mandrel downwardly to its open flow position wherein fluid can flow through ports in the side wall of the tubular body, around the hollow mandrel and into the bore of the tubular body. 
     With the described apparatus, the flow cut off valving mechanism and the sensing device can be concurrently run into the well on a conventional electric wire line, slick line, tubular member or other auziliary conduit, and the flow cut off device manipulated to its closed position through the application of a modes tension to the electric wire line. Subsequent application of fluid pressure to the well conduit above the valving device, and release of the tension on the electric wire line, will effect the return of the hollow mandrel downwardly to its flow open position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1A, 1B and 1C collectively represent a vertical cross sectional view of a well condition sensing device and valving assembly embodying this invention, shown in assembled relationship in a well conduit with the valving elements disposed in their open or flow position; FIGS. 1B and 1C being respectively vertical continuations of FIGS. 1A and 1B. 
     FIGS. 2A, 2B and 2C are views similar respectively to FIGS. 1A, 1B and 1C, but showing the valving elements in their flow cut off position. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to the drawings, there is shown a well conduit 1 which extends into a production zone (not shown). The well conduit 1 may comprise a well casing or a liner, production tubing, and, in any event, constitutes the primary conduit by which production fluid from the well is transmitted to the surface. Well conduit 1 includes a special nipple section 2 threadably connected in the conduit string and defining at its upper end an outwardly facing, inwardly projecting, annular no-go shoulder 2a. Below the no-go shoulder 2a, the special nipple 2 is provided with a downwardly facing locking shoulder 2b above an annular recess 2c. Below the locking shoulder 2b, the special nipple 2 is provided with an extended length of seal bore surface 2d having a greater diameter than the minimum diameter of the no-go shoulder 2a. 
     The combination well condition sensing device and flow cut off valve is represented generally by the numeral 10. Such assembly is run into the well on a conventional electric wire line 3, slick line, tubular member or other auxiliary conduit, the connection of which to the assemblage 10 will be hereinafter described. Assemblage 10 includes an outer tubular anchor housing assemblage 20, an annular elastomeric seal 26, a seal compression assemblage 30, and a hollow mandrel 40. Seal compression assemblage 30 is mounted for axially slidable movement relative to the outer tubular housing assembly 20 by an upwardly projecting sleeve 31 which slidably engages a bore portion 21 of the anchor housing assembly 20. The hollow mandrel assembly 40 is in turn slidably mounted within a downwardly extending sleeve 32 secured to the lower end of the annular seal compression assembly 30 for axial movements relative to the seal compression assembly. 
     The upper end of the outer tubular anchor housing assembly 20 includes an anchor sub 22 which defines at its top end, a downwardly facing annular stop shoulder 22a which engages the no-go shoulder 2a of nipple 2 and positions the entire assembly 10 relative to the special nipple 2. Anchor sub 22 further includes a plurality of peripherally spaced, radially shiftable lock elements 23 which are of conventional construction and urged by springs (not shown) or other biasing means to a radially outer position so that when the lock elements 23 are positioned opposite the recess 2c immediately below the locking shoulder 2b, they will spring outwardly into engagement with recess 2c and thus restrain the entire assembly 10 from upward movement relative to the well conduit 1, as shown in FIG. 1A. 
     Anchor sub 22 is connected by threads 22b to the upper end of a spacer sub 24 which in turn is connected by threads 24a to the upper end of a seal mounting sub 25. Seal mounting sub 25 defines an annular recess at its lower end to accommodate, in conventional fashion, an annular elastomeric seal 26. The diameter of seal 26 is selected to be less than the minimum diameter of the no-go shoulder 2a so that the seal 26 may readily pass such shoulder; however, the seal 26 is expandable through compressive forces produced by upward movement of the seal compression assembly 30 to expand such seal into intimate sealing engagement with the seal bore surface 2d of the special nipple 2. 
     The seal compression assembly 30 includes a compression sub 33 which is threadably secured by threads 33b at its upper end to the guide sleeve 31 and by threads 33c at its lower end to the mandrel guide sleeve 32. Compression sub 33 includes an outwardly and downwardly inclined top surface 33a which engages a correspondingly shaped surface on the annular elastomeric seal 26. Hence, upward movement of the seal compression assembly 30 will effect a compression of annular seal 26 and an outward displacement of said seal into sealing engagement with the seal bore surface 2d. Additionally, the compression sub 33 is provided with a plurality of peripherally spaced radial equalizing ports 34 which provide communication to the annulus from the interior of the inserted assembly 10 and the bore 1a of the well conduit 1 to the interior bore of the inserted assembly for a purpose to be hereinafter described. 
     The upstanding guide sleeve 31 is provided at its upper end with a radially enlarged shoulder portion 31a which cooperates with the upper end of the seal mounting sub 25 to limit the downward movement of the seal compression assembly. An internally projecting shoulder 24b provided on the spacer sub 24 limits the upward movement of the guide sleeve 31 relative to the anchor assembly 20. 
     As previously mentioned, hollow mandrel assembly 40 is mounted within the bore of depending guide sleeve 32 for relative axial movements with respect to the compression sub 33. More specifically, a head portion 41 of the hollow mandrel 40 is provided with a reduced diameter axial bore 41a and an exterior enlarged shoulder portion 41b which slidably engages the internal bore surface 32a of guide sleeve 32. The limits of axial movement of head 41 are determined at the top by the compression sub 33 and at the bottom by an inwardly projecting shoulder 32b formed on the bottom end of the guide sleeve 32. 
     A plurality of peripherally spaced radial fluid flow ports 32d are provided in guide sleeve 32 below the compression sub 33. In the open flow position of the mechanism shown in FIGS. 1A, 1B and 1C, produced fluid will flow upwardly around hollow mandrel assembly 40 and through ports 32d into the bore of anchor housing assembly 20 and thence through the bore of the well conduit 1 to the surface. 
     The upper end of the head 41 of the hollow mandrel assembly 40 is provided with an upwardly facing sloped surface 41e which engages a correspondingly shaped downwardly facing surface 33d formed on the interior of the compression sub 33. The inter-engagement of these surfaces will cause the compression sub 33 to be moved upwardly by the hollow mandrel 40 to the fluid cut off position shown in FIGS. 2A, 2B and 2C. 
     In this fluid cut off position, a pair of O-rings 46 mounted on the periphery of the head 41 of the hollow mandrel assembly 40 engage a seal bore or valve seat 33e defined in the compression sub 33. Fluid flow through the ports 32d is therefore effectively blocked from entering the bore of the hollow tubular assemblage 20. Concurrently, the annular elastomeric seal 26 is urged outwardly into sealing engagement with the seal bore surface 2d of the well conduit 1 to eliminate fluid flow around the inserted assemblage 10, as clearly shown in FIGS. 2A, 2B and 2C. 
     The lower portion of the head 41 is provided with an enlarged counter-bore recess 41c within which is mounted an electric wire line anchor 42. The bottom end of the electric wire line 3 is mechanically secured in conventional fashion to the wire line anchor 42. Anchor 42 in turn is sealably mounted in the counter-bore recess 41c. Depending from the cable anchor 42 is a mounting tube 51 for supporting desired electric pressure and/or temperature sending devices 50 to determine the well conditions. Electrical connections (not shown) are provided in tube 51 for connecting the electrical conductors in electric wire line 3 to sensing devices 50. Devices 50 are of conventional construction and are of the type that are electrically actuated and produce electric signals. The necessary supply of current to devices 50 and the return of the electric signals generated to the surface is accomplished by the electrical conductors conventionally incorporated in the electric wire line cable 3. 
     The lower end of head portion 41 is threadably secured as by threads 41d to the upper end of an externally threaded sleeve 43. An internally threaded spring anchor ring 44 is adjustably positioned on the external threads of sleeve 43. A compression spring 45 is mounted between anchor ring 44 and the bottom end of the depending guide sleeve 32, and thus imparts a downward bias to the hollow mandrel assemblage 40 urging it to the position shown in FIGS. 1B and 1C. 
     While it is not essential, other types of mechanically actuated well condition sensing devices 60 may be mounted on the bottom end of sleeve 42 by being threadably connected to a thread cross-over sub 48. Such mechanically actuated pressure and temperature measuring devices may be provided as insurance against the failure of the electric type sensing devices 50. 
     OPERATION 
     In the operation of the described mechanism, the entire assembly including the electric sensing devices 50, the hollow mandrel assembly 40, the seal compression assembly 30 and the outer tubular anchor assembly 20 are lowered into the well on electric wire line 3. As mentioned, when the shoulder 22a on the anchor sub 22 of the outer tubular anchor assembly 20 seats on the no-go shoulder 2a in the special nipple 2, the locks 23 move radially outwardly into the aligned annular nipple recess 2c and are engagable with the downwardly facing nipple shoulder 2b to prevent further upward movement of the inserted anchor body assembly 20 relative to the well conduit 1. 
     In the position of the apparatus shown in FIGS. 1B and 1C, well fluids can flow freely upwardly around the exterior of the hollow mandrel assembly 40 and enter the interior bore of the inserted assembly 10 through the peripherally spaced flow ports 32d provided in the ending guide sub 32. From this point, the fluid passes upwardly through the internal bore of the seal compression assembly 30 and the tubular anchor body assemblage 20. 
     The applications of an upward tensile force to the electric wire line 3 will produce an upward movement of the hollow mandrel assembly 40 and thus Bring the O-rings 46 provided in the mandrel head portion 41 into sealing engagement with the seal bore 33e defined by the seal compression sub 33, as shown in FIGS. 2B and 2C. Additionally, the end face 41e of the head portion 41 of the hollow mandrel assembly 40 will engage the downwardly facing abutment surface 33d provided on the seal compression sub 33 and force the sub 33 upwardly, thus compressing the annular elastomeric seal 26 into intimate sealing engagement with the adjacent seal bore surface 2d of the special nipple 2. 
     It is therefore apparent that all fluid flow through the well conduit 1 in interrupted through the inter-engagement of the O-ring seals 46 with the seal bore surface 33e, thus preventing any fluid flow passing through the peripherally spaced flow ports 32d from entering the interior bore of the inserted assembly 10, while the compression and outward displacement of the annular elastomeric seal 26 prevents any fluid passage along the exterior of the inserted assemblage 10. 
     It is therefore apparent that the well condition sensing devices 50 and the flow control valving unit are concurrently run into the well in a single trip on an electric wire line. Furthermore, the valve elements may be repeatedly actuated to a closed position by applying an upward tensile force on the electric wire line sufficient to cause upward movement of the hollow mandrel assembly 40 into the valve closing position shown in FIGS. 2B and 2C. 
     To return the valving elements to their open flow position, as illustrated in FIGS. 1B and 1C, it is only necessary to relax the tension on the electric wire line 3 and then apply sufficient fluid pressure down the well bore, such as nitrogen gas, to equalize the formulation fluid pressure operating on the hollow mandrel assemblage 40 to hold it in an upward position. Such equalization of fluid pressure is conveniently achieved through the provision of the plurality of peripherally spaced ports 34 provided in the upper portion of the seal compression sub 33, between valve seat 33e and outer seal 26. 
     Each port 34 has an enlarged counter bore 34a and a conventional check valve 34 (shown only schematically in the drawings) mounted in each counter bore 34a which permits only outward flow through ports 34. Once the pressure differential across the hollow mandrel assembly 40 is removed or substantially reduced, the compressed spring 45, plus the weight of hollow mandrel assembly 40 will effect the return of the hollow mandrel assemblage to the position shown in FIGS. 1B and 1C. 
     At the completion of the testing operations, the aforedescribed mechanism may be conveniently removed from the well conduit. First the electric wire line 3 is sheared at a deliberately weakened zone provided immediately adjacent to the cable anchor 42. A conventional retrieving tool (not shown) having an equalizing prong or other means to actuate the valve 34 is then run into the well on a wire line and engages an upstanding fishing neck portion 22c provided on the top of the anchor sub 22. The retrieving tool incorporates conventional means for effecting the retraction of the locking dogs 23, following which the entire assemblage may be pulled from the well by the retrieving tool. The prong depresses a nub (not shown) on the valve 34 to equalize pressure across the device. Thereafter the retrieving tool engages the portion 22c. It is therefore apparent that a minimum of running operations are required to effect the installation of the combination tool in the well and its subsequent removal. 
     Those skilled in the art will recognize that the sealing arrangement between head portion 41 of the hollow mandrel assemblage 40 and the seal compression sub 33 is only typical of a number of well known sealing arrangements. Thus, the seal compression sub 33 could be provided with an elastomeric sealing material on the downwardly facing surface 33d which is engaged by the top surface 41e of the head portion 41 of the hollow mandrel assemblage 40. The essential feature is that a seal is achieved to interrupt fluid flow from the exterior of the tool into the bore through the cooperation of two annular valving elements, and the electric wire line for operating the valving elements passes through the bore of the two annular valving elements. 
     Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.