US3384180A - Pressure balanced testing tool - Google Patents

Description

May 21, 1968 l.. E. PERKINS PRESSURE BALANCED TESTING TOOL 2 Sheets-Sheet l Filed March '50, 1966 INVENTOR.

LEE E. PERKINS wlr a.) MJL; L.. ATTORNEYS May 21, 1968 E. PERKINS PRESSURE BALANCED TESTING TOOL 2 Sheets-Sheet Filed March 50, 1966 ATTORNEYS United States Patent O 3,384,180 PRESSURE BALANCED TESTING TGGL Lee E. Perkins, Houma, La., assigner to Halliburton Company, Duncan, Okla., a corporation of Delaware Filed Mar. 30, 1966, Ser. No. 538,812 6 Claims. (Cl. 166-226) ABSTRACT 0F THE DISCLOSURE A well tool including a uid reservoir and a member movable through the reservoir. This movable member has passage means extending longitudinally of the reservoir and operable to receive Huid metering, i.e., flow restricting, pins. An annular circumferentially extending groove supports an annular seal for axial movement within fixed axial limits. The seal defines a closure for one reservoir end. Port means provide fluid communication between the seal and .well fluid external of the tool.

General background and objects of invention This invention relates to apparatus for use in well bores. In particular, it relates to a submersible apparatus including a pressure balancing seal.

The invention is presented in the context of a uniquely advantageous environment where the pressure balancing seal is incorporated in a well testing tool which is adapted to control the flow of uid within a well bore While testing the productivity of subterranean formations.

ln United States Farley Patent 3,305,023, entitled Apparatus for Use in Well Bores, and assigned to the assignee of this application, a testing tool is fully described which is uniquely adapted to be structurally and functionally integrated with the pressure balancing seal of this invention.

The testing tool in question includes a cavity between relatively movable components which defines a fluid reservoir in which is positioned a movement impeding coupling.

The tluid reservoir of this testing tool has relatively movable wall components which are in slidable and sealed relationship. However, the slidably sealed walls are exposed to the pressure of fluids in the annulus of a Well bore. Fluid within the tool reservoir is placed in the tool under generally ambient, well head pressure conditions. Thus, as the tool is lowered into the well the annulus pressure will progressively increase and tend to create a progressively increasing pressure differential across the seals which provide slidable and scalable engagement between the movable wall portions of the reservoir.

in practice it has been found that this pressure differential tends to cause well sediment and seal cuttings (i.e., abraded seal particles) to be forced by the pressure differeniial into the reservoir. This effects an undesired contamination of fluid within the reservoir and additionally tends to clog small orices of the movement impedance coupling. (In order to fully appreciate the structural characteristics of the movement impeding coupling reference may be made to the United States Schwegman Patent 2,740,479, issued Apr. 3, 1956.)

Recognizing the need for an improved seal arrangement in the submersible reservoir of the above-described well tool, there is presented through this invention, a pressure balancing seal which itself serves to substantially equalize the pressure differential across the seals of the tool reservoir.

It is likewise an object of the invention to provide such a pressure balancing seal which will tend to prevent the influx of annulus sediment or seal cuttings into the tool reservoir housing the movement impeding coupling.

Another object of the invention is to provide such a "ice pressure balancing seal which is characterized by unique structural simplicity accompanied by a high degree of operational reliability.

It is also an object of the invention to provide improved well tool apparatus including such a pressure balancing seal and which enables the maintaining of positive control over the selective or sequential operation of the valves of a plural-valved well tool.

An additional object of the invention is to provide a multi-valved well tool including such a pressure balancing seal and wherein essentially linear movements of a well string effect the controlled operation of the various tool valves. A tester valve may be repeatedly operated by merely lowering and raising the string and a circulating valve may be operated by the mere manipulation of a lug and slot connection.

Yet another object of the invention is to provide such an improved well tool including a pressure balancing seal and which yields a positive well head indication of the successful operation of individual valve components.

It is also an object of the invention to provide such an improved multi-valved, well tool including a pressure balancing seal and wherein the rate of operation of one valve is different than the rate of operation of another valve in response to the same applied operating force so that a desired sequence of valve operation is assured.

It is also an object of the invention to provide a multivalved well tool including a pressure balancing seal and in which holding means are associated with one valve to maintain its operating components effectively immobilized while the components of another valve are being operated and to interrupt the immobilizing effect of this holding means by the same force applied to operate the components of other valves.

It is a specific object of the invention to provide a well tester tool affording positive and reliable control over the sequential or selective operation of a tester and circulating valve.

General summary of overall invention For accomplishing the basic objects of this invention there is presented a submersible apparatus including resservoir means adapted to be submerged in uid and contain fluid within its interior. Passage means in the apparatus provide pressure transmitting communication between fluid within the reservoir means and fluid outside of the reservoir means. Seal means, movably mounted in the passage means, tend to equalize the pressure of fluid within the reservoir means and uid outside of the reservoir means.

Other independently significant facets of the invention lrelate to the tubular and telescoping characteristics of walls defining the reservoir means, the annular character of the passage means, and the manner in which the seal means is mounted for slidable movement between abutments of the annular passage means.

Still further independently signcant facets of the invention entail the combination of a fixed seal at one end of a reservoir dened by movable tubular members `and a slidable seal at the other end of the reservoir, with both seals being in communication with the liuid outside of the reservoir and uid inside of the reservoir.

Probably the most significant advantages of the invention are derived from the basic combination above-described when fluid flow restricting orice means are contained within the reservoir means. But for the movable pressure equalizing seal means, the orifice means would be vulnerable to clogging by debris carried past the reservoir seals into the reservoir interior.

The apparatus presented through this invention, in part, involves an embodiment comprising a first tool portion, a second tool portion upon which the first 4portion is mounted for limited telescoping movement, and a third portion upon which the second portion in turn is mounted for limited, telescoping movement. First slide valve means are carried by these first and second tool portions. Second slide valve means are carried by the second and third tool portions. The reservoir and movable seal means of the invention are incorporated between the second and third tool portions.

In the context of this embodiment, means may be interposed between the second and third tool portions to impede, without preventing, relative telescoping movement of the second and third portions. Thus, an axial force imposed upon the first tool portion and directed toward the third tool portion will tend to cause the relative telescoping movement of the first and second tool portions at a more rapid rate than the relative telescoping movement of the second and third portions induced by this imposed force.

In the context of the embodiment previously described, the second slide valve means may comprise a telescopable slide valve assembly detachably secured within the second and third tool portions.

Drawings In describing the invention, reference will be made to a preferred tester tool embodiment illustrated in the accompanying drawings.

In these drawings:

FIGURE 1 is a schematic, sectional and elevational View of a portion of a well string including a preferred tester tool structure in association with a Well packer. FIGURE 1 generally retiects the position of the tester tool and packer components as they may be arranged While the tool is being moved through a well bore toward a test site;

FIGURE la provides a schematic and enlarged illustration of a lug and slot connection which may be employed between mandrel and upper casing components of the FIGURE 1 tester tool;

FIGURE 1b provides an enlarged and schematic illustration of another lug and slot connection which may be employed between valving components associated with the packer unit of the FIGURE 1 assembly;

FIGURE 2 is a schematic, elevational and sectional view of the FIGURE 1 assembly illustrating the arrangement of tester tool components with the tester valve in the open position;

FIGURE 3 is a schematic, elevational and sectional view of the FIGURE 1 assembly illustrating tool components as they would be disposed with the circulating valve of the tester tool open;

FIGURES 4a and 4b, when joined along the connecting line A-A provide an enlarged, vertically sectioned, fragmentary nad somewhat schematic view of a portion of the FIGURE 1 tester tool including a movement irnpeding fluid coupling; and

FIGURE 5 is a cross-sectional view of a portion of FIGURE 4a showing how the reservoir of the movement impeding coupling of the tool extends around a connecting device within the tool.

Major components FIGURE 1 illustrates a tester tool 1, the upper end of which is adapted to be supported upon a conduit string 2 by coupling means such as a conventional threaded connection 3. A packer and valve and assembly 4 is carried on the lower end of the tester tool 1.

In referring to the drawings and describing the basic structural components, it will be understood that these well tool components possess the usual, generally cylindrical or annular Well tool configurations.

Tester tool 1 includes central mandrel means 5. Upper or first casing means 6 are telescopingly mounted over mandrel means 5. First connecting means 7 extend between the mandrel means 5 and the upper casing means 6. This connecting means is of the so-called I-slot type and may include a plurality of mandrel-means-carried slots 701 within each of which is disposed an upper casing-means-carried lug 702.

In the elevational view of a representative slot 701 as shown in FIGURE la, it will be seen that each slot comprises a longitudinally extending, elongate upper portion 701:1, an intermediate shoulder '701]7, a laterally extending portion 701C, and a relatively short, longitudinally extending portion 701d. As illustrated, longitudinal slot portion 701d is displaced in a generally counterclock- Wise direction from slot portion 701a when the tool is viewed from its upper end.

As will be apparent, the lug and slot connection 7 permits limited telescoping movement of the upper casing means 6 relative to the mandrel means 5.

A lower or second casing means 8 is telescopingly mounted over mandrel means S and axially spaced from the upper casing means 6 as shown in FIGURE 1.

Second connecting means 9 extend between the mandrel means 5 and the casing means 8. As schematically shown in FIGURE 1, connecting means 9 may comprise an upper portion 9a including mandrel-rneans-carried lugs 901 disposed abuttingly beneath a casing-means-carried shoulder 902. Shoulder 902 is disposed, as shown in FIGURE 1, between the mandrel lugs 901 and a mandrel means shoulder 903. A coil spring 904 may be interposed between shoulders 902 and 903 to tend to hold the casing means S and mandrel means 5 in the extended position shown in FIGURE l, with the engagement of lugs 901 and shoulder 902 limiting downward, axial movement of casing means 3 on mandrel means 5.

Slide valve means 10 are detachably secured within the mandrel means 5 so as to be capable of telescoping movement through the tester tool interior when disconnected from the mandrel means 5. This slide valve means 10 may carry a conventional pressure recorder 1001 as shown.

Slide valve means 10 corresponds generally to the detachable valve assembly described in United States Farley Patent 3,190,360, issued I une 22, 1965, and entitled Well Tester with Retrievable Valve Assembly.

Slide valve means 10 includes an upper portion 1002 adapted to be secured by selectively releasable coupling means 1003 to mandrel means 5 for unitary movement with the mandrel means. This coupling 1003, described in detail in the aforesaid Farley Patent 3,305,023, and described in basic format in United States Schwegman Patent 2,740,479, prevents axial movement of the upper slide valve portion 1002 relative to mandrel means 5.

First port means comprising one or more ports 1004 are carried by slide valve portion 1002. Ports 1004 extend generally radially of the tool axis.

A second slide valve portion 1005 is contained within lower casing means 8 as shown in FIGURE 1. Lower slide valve portion 1005 may be provided with blocks 1006 which intermesh with casing-means-carried splines 801 so as to prevent relative rotation of the slide valve portion 1005 and casing means 8. Additional lugs 1007 may be provided to rest upon axially grooved, casing means 8 carried shoulder means 802 so as to prevent downward movement of the valve portion 1005 relative to the casing means 8.

Second port means comprising one or more ports 1008 are carried by the slide valve portion 1005 and extend generally radially of the tool axis.

The upper and lower slide valve portions 11002 and 1005 are urged apart by a coil spring 1009 and are splined together for relative telescoping movement as hereinafter described. Slide valve portions 1002 and 1005 detine the centrally disposed and axially extending -frst tluid passage means A.

As will be apparent by reference to FIGURE 1, downward telescoping movement of valve portion 1002, relative to valve portion 1005, induced by downward telescoping movement of mandrel means 5 within casing means 8 will serve to move ports 1004 and 1008 into mutually communicating alignment.

With ports 1004 and 1008 Ialigned, tluid communication will be established between axially extending passage means A and the exterior of slide valve portion 1005.

Third port means comprising one or more ports 501 are carried by the mandrel means 5 and extend generally radially of the tool axis.

Fourth port means comprising one or more ports 601 are carried by the upper casing means 6 and also extend generally radially of the tool axis.

Upper casing means 6 and mandrel means 5 dene second, centrally disposed and generally axially extending, fluid passage means B. Second fluid passage means B, as shown in FIGURE 1, communicates with rst passage means A of the slide valve means and the third port means 501 of mandrel means 5.

Downwardly directed telescoping movement of first casing means 6 relative to mandrel means 5, as permitted by appropriate manipulation of J-slot connecting means 7, is effective to bring ports 601 into communicating alignment with ports 501.

Lower casing means l8 defines third,` generally centrally disposed 'and axially extending, fluid passage means C. Fluid passage means C provides fluid communication between the interior 401 of packer 4 and second port means 1008. In a conventional fashion, blocks 1006, splines 801, lugs 1007, and shoulder means 802 are configured so as to provide for uid flow around recorder 1001 and between the packer interior 401 and port means 1008.

Packer assembly 4, as schematically shown, may conveniently include packer setting drag springs 402, a radially expandable seal portion 403, and a slide valve portion 404. Slide valve portion 404 may comprise a radially ported outer -sleeve portion 405 telescopingly connected to an inner, radially ported sleeve portion 406 by lug land slot connecting means 407.

As shown in FIGURE lb, lug and slot connecting portion 407 may comprise one or more slots 408 formed on outer sleeve portion 405. Within each slot there is received a lug 409 carried by sleeve portion 406. With a lug 409 positioned in slot 408 as shown in FIGURE 1b, sleeve ports 410 and 411 are held in communicating alignment. In order to move ports 411 axially downward and ont of communicating alignment with ports 410, it would be necessary to rst rotate the lug-carrying sleeve 406 clockwise when viewing the tool from the top, and then move sleeve 406 downwardly.

Connecting means 9 may further include an hydraulic, t

impedance coupling 9b interposed between the mandrel means 5 and the lower casing means 8. This hydraulic mechanism functions somewhat like a check valve in combination with a restricted bypass as described in the aforesaid Farley Patent 3,305,023 and in U. S. Schwegman Patent 2,740,479. When a downwardly directed force is transmitted from upper casing means 6 through the lug and slot connection 7 to mandrel means 5, mandrel means 5 tends to telescope downwardly within casing means 8. However, the interposed coupling 9b impedes, without preventing, this telescoping movement as described in the aforesaid Schwegman patent. Thus, a downwardly directed axial force imposed through string 2 upon upper casing means 6 will tend to induce relative telescoping movement of casing means 6 and mandrel means 5 at a more rapid rate than relative telescoping movement of mandrel means 5 within casing means 8. With lugs 702 disposed in slot portions 7011i, a downward force imposed upon upper casing 6 will move yports 601 and 501 into communicating alignment before mandrel means 5 telescopes within casing means 8 suicient to bring ports 1004 and 1008 into communicating alignment and before mandrel means 5 has moved sufliciently to bring the lower end y602 of upper casing means 6 into abutting engagement with the axially spaced and mutually facing upper end 803 of lower casing means 8.

It should be noted that the 'axial space between casing end portions 602 and 803 is so limited as to prevent the alignment of ports 1004 and 1008 subsequent to the alignment of ports 601 and 501. Thus, telescoping movement of upper casing means 6 over mandrel means 5 suiicient to bring ports 601 and 501 into communicating alignment will bring casing end portions l602 and 803 into such close proximity as to prevent telescoping movement over mandrel means `5 within casing means 8 sufficient to align ports 1004 and 1008.

Piston means 11 are mounted within and slidably carried by the upper portion of upper casing means 6 as shown in FIGURE 1. The slidable movement of piston means 11 is limited =by an upper-casing-means-carried shoulder 1101 and abutment means 1102.

An annular pressurized Huid chamber .D is defined by piston means 11 and upper casing means 6. Pressurized fluid contained within chamber D will tend to move piston means 11 toward abutment means 1102 and the upper end 502 of casing means 5. Radially extending aperture means comprising one or more ports 1103 carried by casing means 6 are adapted to admit pressurized well uid to chamber D.

When casing means 6 has been telescoped downwardly over mandrel means 5 as shown in FIGURE l with lugs 702 on slot shoulders 701b, the upper end 502 of the mandrel means 5 will engage and displace the piston means 11 relatively upwardly and slightly away from abutment means 1102. During the initial part of a subsequent upward telescoping movement of casing means 6 relative to mandrel means 5, piston means 11 will remain in engagement with the upper mandrel portion 502. While thus engaged, a hydraulic force will be transmitted from the well fluid exterior of the casing means y6 to the piston means 11, tending to cause upward movement of casing means 6 with reference to mandrel means 5. Upward movement of casing means 6 suiiicient to bring abutment means 1102 into engagement with piston means 11 will hold piston means 11 out of engagement with mandrel end portion 502 during a terminal part of upward movement of casing means 6.

As will be appreciated, the hydraulic force transmitting effect of piston means 11 will tend to immobilize casing means 6 `and mandrel means 5 in their relative positions shown in FIGURE l with the ports 601 and 501 displaced out of communicating alignment. Thus, while an upward pull is being exerted on string 2 to move ports 1004, upwardly out of communicating alignment with reference to ports 1008, piston means 11 will tend to maintain ports 501 and 601 in the displaced relationship shown in FIGURE 1. After the upper limit of telescoping movement of slide valve portion 1002 relative to slide valve portion 1005 has been reached such that mandrel means 5 becomes anchored against further upward movement, continued upward movement of string 2 will bring abutment means 1-102 into engagement with the piston means 11 and move this piston means out of force transmitting relationship in connection with mandrel end portion 502. `Owing to the interruption of the immobilizing eiect of piston means 11 and the thus induced loss of the pressurized uid coupling between mandrel end portion 502 and the upper casing means shoulder 1101, a noticeable loss of hydraulic lifting force imposed against the casing means shoulder 1101 and thus the string 2 will result.

The annular, reactive area of piston means 11 within pressurized chamber D is preferably of such a magnitude that when piston means 11 engages casing end `502 a net, overall hydraulic force is provided acting upon upper casing means 6 and mandrel means 5, which would tend to move casing means 6 upwardly and mandrel means 5 downwardly if these components were unrestrained.

Desirably, the other areas of casing means 6 and mandrel means exposed to well bore fluid pressure and to internal tool fluid pressure for equalizing or ventingv purposes are such as to provide a net hydraulic force insufficient to tend to move the casing means 64 upwardly relative to the mandrel means S. However, with the pisto means 11 in force transmitting engagement with the upper mandrel end 502, the net hydraulic reactive forces imposed upon the exposed surfaces of the casing means 6 and the mandrel means 5 are suiiicient to result in a force tending to raise causing means 6 relative to mandrel means 5.

An additional or second piston means 12 may comprise an integral portion of the lower end of mandrel means 5 as shown in FIGURE l. Piston means 12 is mounted within lower casing means 8 in force transmitting relation with mandrel means 5. This force transmitting relation, in the illustrated embodiment, results from the integral incorporation of the piston means 12 with the mandrel means 5.

Piston head means 1201 are formed in casing means 8 as illustrated in 'FIGURE 1. An annular pressurizing fluid chamber E is defined between piston means 12 and piston head means 1201. Radially extending aperture means comprising one or more ports 1202 intersect the wall of lower casing means 8 to provide iluid communication between the chamber E and the exterior of the easing means 8 and to admit pressurized well bore uid to the chamber E.

Additional, radially extending aperture means comprising one or more ports 1203 may extend through the portion of mandrel means 5 adjacent and above piston means 12.

Piston means 12, pressurized chamber E and piston head means 1201 define an hydraulic force transmitting coupling between mandrel means 5 and lower casing means 8. Pressurized well bore fluids admitted through ports 1202 into chamber E will exert an upward lifting or balancing force against mandrel means 5. Even though mandrel means 5 is being moved upwardly, this hydraulic coupling will enable force to be transmitted between the mandrel means 5 and the casing means 8 to other well bore components such as the packer assembly 4. During downward movement of mandrel means 5, fluid displaced within the annular zone F may be vented through ports 1203 into the gradually enlarging portion of the chamber E lying above the piston means 12.

As shown in 4FIGURE, 1 in a schematic sense and in FIGURES 4a, 4b, and 5 in detail, the testing tool 1 is provided with a unique pressure balancing seal 14. Seal 14 is located at the upper end of the connecting means 9.

The lower casing means 8 and the mandrel means 5, in essence, constitute a rst tubular member which telescopingly receives a second tubular member. Portions of the outer periphery of the second tubular member, i.e., mandrel 5, are spaced radially inwardly of the inner periphery of the rst tubular member, i.e., casing means 8, so as to define a iluid reservoir or cavity H.

Cavity H is generally annular in character and is closed at its lower end by, xed elastomeric O-rings 15. As shown in FIGURE 4b, O-rings 15 may be carried on the inner periphery of the casing means 8 so as to slidably and sealingly engage the outer periphery of the mandrel means The upper end of the cavity of annular reservoir H is closed by the pressure balancing seal means 14. Seal means 14 may comprise an annular elastomeric member 1401 mounted for axial slidable movement in an annular and axially elongate slot 1402 formed on, and facing radially inwardly from, the casing means 8.

Fixed seal 15 and pressure balancing seal 14 are located on axially opposite sides of the movement impending coupling 9b as shown in FIGURES 4a and 4b. Seal 14 is in pressure transmitting communication with seal 15 assuming, of course, that the cavity H between the seals 14 and 15 is fully filled with iluid such as oil. As

shown in FIGURE 5, portions of the cavity H bypass around elements of the coupling 9a. As is described subsequently and in greater detail, the impedance coupling 9b enables uid pressure to be transmitted through itself. Thus, with the cavity H being fully lled and with pressure -being able to be transmitted around and/or through the coupling components 9a and 9b within the cavity H, the pressure communicating relationship between the seals 14 and 15 becomes apparent.

The axially slidable movement of the pressure balancing seal 1401 within the slot 1402 is limited by an upper slot shoulder or abutment 1043 and a lower slot shoulder or abutment 1404. The cavity H is filled with suicient iluid to hold the seal 1401 spaced axially above the shoulder 1404.

Slot 1402, as will be apparent by reference to FIGURE 4a, constitutes an annular passage portion, This annular passage portion is in iluid communication with one or more ports P in the casing means 8. Thus, the seal 1401 is in fluid communication, on its upper side, with annulus pressure external of the casing means 8. Seal 1401 on its lower side, and by way of the annular passage portion 1402, is in pressure transmitting communication with uid filling the cavity H.

Similarly, seals 15 communicate through ports such as the ports Q in the mandrel means 5, the interior of the mandrel means 5, and lateral ports or an open lower end of the tool 1, with the pressure of annulus uids external of the casing means 8. Fixed seals 15 also communicate with uid in the lower end of the cavity or reservoir H.

With respect to the communication of seals 15 with fluid external of the casing 8 and Huid within the cavity H, it will be understood that such communication results from the necessary clearances between the metallic casing means 8 and metallic mandrel means 5, even though such clearances may not be clearly apparent from the reduced scale of the drawings.

O-rings seals 15 and annular floating seal 1401 conventionally will be fabricated of elastomeric material such as rubber or neoprene. Such conventional seal materials are, of course, abradable to some limited extent.

Mode of operation of tool FIGURE l illustrates the disposition of tool components as they would generally be arranged while running the tester tool 1 into a well bore 13.

In the running-in position, the packer seal `403 would be in its unexpanded condition and the packer drag spring 402 would lbe in frictional engagement with the Wall of the well bore 13. In all probability, the ports 410 and 411 would be aligned, as shown, when the slide valve assembly 10 was latched within the tester tool interior during the running-in operation.

While the tester tool assembly is being moved downwardly through a well bore, it should be noted that the upper piston means 11 exerts a hydraulic separating force between the upper casing means 6 and mandrel means 5. This force tends to maintain these tool components in the position shown in FIGURE 1, even apart from the lug and slot control imposed by connecting means 7. This, of course, immobilizes port means 501 and 601 out of mutually communicating alignment and thus holds the circulating valve closed.

While tester tool 1 may be moved into position with the slide valve assembly 10 already mounted within its interior, it would also be feasible, where desired, to pump the valve assembly 10 downwardly into the tester tool 1 after it has been disposed at a well bore test site. Such pumping-in of the valve assembly 10l will effect the automatic operation of the connecting means 1003 so as to latch valve portion 1002 for non-axial movement with the mandrel means 5. The general manner in which this automatic latching operation is accomplished is described in detail in Farley Patent 3,190,360.

After a test site has been reached, the packer 4 may be set and expanded by conventional operating techniques, well known in the art, and not relevant to this invention. In order to prepare for the testing operation, the packer seal 403 would be radially expanded into sealing engagement with the wall of the well bore 13. Additionally, the string would be turned clockwise and moved downwardly to move port means 411 out of communicating alignment with port means 410 as shown in FIG- URE 2.

It should be noted that in the running-in position, the tester slide valve as defined by ports 1004 and 1000 would also be closed, with the impedance coupling 9b tending to prevent inadvertent tester valve opening.

The initiation of a testing operation is illustrated in FIGURE 2. As there shown, the tester valve ports 1004 and 1008 have been moved in communicating alignment. This alignment was achieved by exerting downward force on the string 2, with the connecting lugs 702 engaging slot shoulders 701b as shown in FIGURE la. This downward force was thus transmitted through lugs 702 and casing slot shoulder portions 701b and through connecting means 1003 to slide valve portion 1002. This force, of a magnitude suiiicient to overcome the various hydraulic reactive forces imposed upon the tool and the biasing effect of coil springs 904- and 1009, serves to move the slide valve portion 1002 telescopingly into the slide valve portion 1005 to which it is joined by splined connecting means as hereinafter described.

Proper alignment of test valve ports 1004 and 1008 may be assured by appropriate axial spacing between piston head defining shoulder 1201 and piston means 12. When mandrel means 5 has been moved downwardly suiciently to bring piston means 12 into abutting engagement with shoulder 1201, port means 1004 will have been brought into radially communicating alignment with port means 1008.

As described in the previously mentioned Schwegman Patent 2,740,479 and as hereinafter summarized, an appropriate bypass may be incorporated near the lower end of the travel path in impedance coupling 9b. This bypass will efrect a sudden interrupting of the movement impeding effect of the impedance coupling 9b and allow the mandrel means 5 to suddenly move downwardly at an increased velocity. The result-ing sudden downward jarring of the string 2 will be reflected at the surface so as to provide an indication of the alignment of the piston port means 1004 and 1008, i.e. the opening of the tester valve. As will be appreciated, of course, this bypass must be disposed so as to eiTect the aforesaid jarring action just prior to the time that the piston means 12 engages the casing shoulder 1201.

With the tester valve ports 1004 and 1008 aligned and the circulating valve ports 501 and 601 misaligned as shown in FGURE 27 well tluids which have entered the interior 401 of the packer assembly 4 from beneath the expanded seal 403 will move through passage means C, into the passage means A and upwardly into passage means B.

While moving around the pressure recorder 1001, the pressure of the sample fluids will be recorded by conventional pressure recording arrangements, not illustrated.

With the tester valve open, casing means end portions 602 and 803 will have converged sufficiently t0 prevent inadvertent opening of the circulating valve by telescoping movement of upper casing means 6 downwardly over mandrel means 5.

After an appropriate interval of time, the tester valve may be closed. The closing of this tester valve is effected by merely raising the string 2.

During the initial part of the raising of the string 2, the piston means 11 will exert a hydraulic separating force against the upper casing 6 and mandrel means 5, tending to hold the ports 601 and 501 out of communieating alignment as heretofore described. Piston means 10 11, during this initial raising of the string 2, in being spaced above and out of engagement with the abutment shoulder 1102, will enable a hydraulic force from adjacent well annulus fluids to be transmitted against the casing means, piston head dening shoulder 1101.

During the upward movement of the string 2, the Coil springs 1009 and 904 will assist in restoring the mandrel means 5, slide valve 10 and lower casing means 8 components to the positions shown in FIGURE 1. Continued upward movement of string 2 will thereafter take place with the mandrel means 5 limited against further axial upward movement, resulting, for example, from engagement of the upper ends of blocks 901 of connecting means 9a with a lower casing means shoulder 902. With mandrel means 5 stabilized against further upward movement resulting from its interconnection with lower casing means 8 and anchoring packer assembly 4, additional upward movement of string 2 will bring abutment means 1102 into engagement with piston means 11 and lift piston means 11 upwardly away from the upper end 502 of mandrel means 5.

When piston means 11 separates from mandrel end 502, the hydraulic lifting force imposed upon string 2 through the action of piston means 11 will be interrupted and thus provide a noticeable surface indication of a change of load on the string 2. The elongate character of the slot portions 701a will provide a substantial period of travel for the string 2 at this changed load value so as to provide a sustained surface indication that the tester valve has been successfully closed and that the connecting lugs 707 are moving upwardly within the elongate slot portions 701a.

As will be appreciated, the opening and closing of the tester valve may be easily repeated as often as desired by merely moving the testing string linearly, down and up.

After a sample has iiowed into the passage means B and the tester valve has been closed, the circulating slide valve may be opened so as to allow the received sample to be circulated to the surface. Thus, with port means 601 and 501 of the circulating valve in communicating alignment as shown in FIGURE 3, fluid may be circulated from a well head downwardly through the annular well space G to move through the aligned circulating valve ports S01 and 601 and displace sample fluid upwardly through the string 2.

The opening of the circulating valve7 with the tester valve closed, is accomplished by rotating the string 2 countercloclrwise so as to move the lugs 702 ot of the shoulders 701:1 so that they may move downwardly through the slot portions 701C and 7 01d.

After the string 2 has been suiiiciently rotated to enable the lugs 702 to move downwardly, a downward force exerted on the string 2 will cause the upper casing means 6 to telescope downwardly over mandrel means S. The movement impeding action of the coupling p0rtion 9b will tend to impede relative telescoping movement of mandrel means 5 within lower casing means 8. As a result, telescoping action of upper casing means 6, sutiicient to bring ports 601 and 501 into communicating alignment will occur prior to any movement of mandrel means 5 sufficient to bring casing means end portions 602 and S03 into abutting alignment or to bring the tester ports 1004 and 1008 into communicating alignment. With the circulating ports 601 and 501 aligned, the upper casing means end portion 602 will have converged toward the lower casing means end portion 803 to `such an extent as to prevent subsequent opening of the tester valve.

With the circulating valve open, fluid may be circulated downwardly through the annular space G for a period of time suicient to displace the sample iiuids from the passage means B, upwardly through the interior of the string 2.

The relative positions of the tester tool components with the circulating valve open and the tester Valve closed are shown in FIGURE 3.

At the completion of a testing operation it may be desirable to then remove the entire tester tool and packer assembly from a well bore. This may be accomplished by conventional manipulations effective to retract the packer seal 403. An upward force exerted on the string 2 will then move the entire tester tool and packer assembly upwardly and out of the well. It should be noted that during such a withdrawal, the upward force exerted upon the string 2 will tend to hold the tester valve and the circulating valve in closed valve positions, i.e. the circulating valve ports 601 will be held above and out of communication with the circulating valve ports 501 and the tester valve port means 1004 will be held above and out of alignment with the tester valve ports 1008.

If additional well `operations are to be performed such as the injection of treating fluids or cement, the slide valve assembly may be disconnected from the mandrel means 5 and moved upwardly through the interior of the mandrel means 5 and string 2 by conventional circulating techniques as described in Farley Patent 3,190,360. To effect this circulating out of the slide valve assembly 10, the connecting means 1003 would be disengaged, the packer assembly ports 410 and 4111 placed in communieating alignment, and uid circulated downwardly through the annular space G and into the packer assembly interior 401.

The manner in which connection 1003 may be released is described in Farley Patent 3,190,360 and in Farley Patent 3,305,023.

With the tool 1 disposed within a well such that the coupling 9 and reservoir H is submerged in annulus fluid, the floating seal 1401 serves effectively to equalize pressure across itself and equalize the pressure of fiuid within the reservoir H and the annulus Huid adjacent and exterior of the casing means 8.

Annulus pressure acting through the ports P of the casing means S on the top of the seal 1401 will tend to move the annular seal 1401 downwardly. This downward movement of the seal y11401 will compress fluid within the cavity H until the pressure within the cavity H is substantially equal to the annulus pressure acting on the seal 1401.

With the pressure within the cavity H, between the seals -14 and 15, being substantially equal to the annulus pressure acting on the outside of the seals 14 and `15 there will be no appreciable tendency for annulus fiuid to migrate past the seals 1'4 and 15 into the cavity H and thereby carry annulus sediment into the cavity H. Similarly, with this pressure equalization there will be little or no meaningful tendency for cuttings abraded off of the seals 15 and 1401 to be carried into the cavity H. In thus avoiding a tendency for well sediment and seal cuttings to enter the cavity H, blocking or obstructing of the ow impeding passages 915 and check valve 910 is effectively avoided.

The equalization of pressure across the seals 15 and across the seal 1401 tends to significantly increase the operating life of these seals. Pressure differences across these seals tends to induce deformation conducive to excessive abrasion and wear.

Structural details FIGURE 4a illustrates details of connection 9a which extends between lower casing means 8 and mandrel means 5. This axially releasable, clutch connection comprises a plurality of blocks 901 which are mounted for longitudinal sliding but non-rotary movement within longitudinal grooves 905 formed on the inner periphery of casing means 8 as shown in FIGURE 4a. The lower ends of grooves 905 terminate and open into an annular recess 906. With the blocks 901 moved down into recess 906, casing means 8 becomes rotatable relative to the mandrel means 5. A coil spring 907 biases the blocks 901 upwardly into the grooves 905.

Each block 901 is slidingly received within a longitudinally extending groove 90S formed on the outer periphery of mandrel means 5 as generally shown in FIGURE 4a.

Cil

When mandrel means 5 is telescoped downwardly within sleeve means 0, an annular shoulder 909 will engage blocks 901 and move these blocks axially downwardly out of grooves 905 and into annular recess 906. With the blocks 901 disposed in the annular recess 906, the mandrel means 5 may be rotated relative to the casing means 8 to effect the releasing operation of the connection 1003 as described in the aforesaid pending Farley Patent 3,305,023, filed May 27, 1964. It will be understood, 0f course, that rotary force is transmitted to mandrel means 5 through casing means 6 by virtue of lug and slot connection 7.

Hydraulic impedance coupling 9b, as shown in FIG- URES 4a and 4b, comprises an O-ring type, elastomeric, check valve member 910 confined for movement between annular shoulder 911 and generally axially apertured shoulder 912. While the outer diameter of mandrel wall portion 913 provides some annular clearance between it and the adjacent wall portion 914 of casing means 8, when the valving ring 910 is disposed as shown, uid flow between this annular clearance is prevented. With the valving ring in this position, fluid contained within the cavity H, in order to move into the space I from the Space J when mandrel means 5 moves downwardly relative to casing means 3, must pass through flow restricting passages 915. Flow restricting, bypass passages 915, as described in the previously noted Schwegman Patent 2,740,479, may be lprovided with metering pins to effectively restrict the ow of uid between the annular spaces I and I. As will be appreciated, the diameter of the mandrel portion 916 adjacent the exits 917 of the restricted ffow passages 915 should be such as to ybe spaced from the adjacent inner wall portion 918 of mandrel means 5 so as to provide an adequate flow passage leading into the chamber I.

At the lower end of space J, an additional fiuid bypass passage 919 may be provided in the wall of casing means 3, including an entrance 920 and an exit 921.

With the arrangement of components of impedance coupling 9b as described, and with the chamber H containing previously inserted hydraulic uid, a hydraulic impedance coupling action will result as described in the aforesaid Schwegman patent. Downward movement of the mandrel means 5 will cause the valving ring 910 to move into the seat 911 and cause fluid to flow through restricted passage means 915 from the space I to the space I. The ow impeding effect of the bypass passage means 915 will tend to delay or impede telescoping movement of mandrel means 5 until the valving ring 910 is moved between entrance 920 and exit 921 of bypass passage 919. With the valving ring 910 disposed between the entrance 920 and exit 921, sufficient additional bypassing of the ring 910 will occur as to enable a sudden relatively rapid downward movement of the mandrel means 5.

Upward movement .of mandrel means 5 will not be effectively impeded by the check valving ring 910 due to the resulting movement of the ring 910 against the shoulder 912. This movement of ring 910 will enable fluid to bypass the ring 9.10 and move from space I through the space between surface 918 and mandrel portion 916, through the space between surfaces 913 and 914, and through the ring ports 922 into the space J as generally described in the aforesaid Schwegman patent.

Included throughout the tester tool l1 may be a number of equalizing and/or venting ports of a conventional nature, some of which such as ports P and Q are shown in the drawings. Also included and schematically illustrated are a variety of conventional ring type seals S of differing sizes and types, depending upon the components with which they are associated. Additional conventional components included in the tool are schematically illustrated, rotary or thrust bearing assemblies such as assembly X shown in FIGURE 4a.

It will be understood, that, in describing structural details of the tool, many components which would ordinarily be fabricated from multiple, rotatably interconnected sections are merely illustrated as unitary components so as to avoid obscuring the main aspects of the invention.

Advantages In describing the structure and mode of operation of the prefered tester tool embodiment, several major advantages of the invention have been demonstrated.

The pressure balancing seal concept of the invention affords a prime advantage in that it insures the proper sequence of actuation of tool valving components by preventing the clogging of the impedance coupling 9b which controls the sequence of valve operations. In this sense, the pressure balancing seal is directly, structurally and functionally interrelated to the over-al1 structure of the testing tool.

Of p-articular importance is the manner in which the pressure balancing seal tends to prolong seal life by avoiding abrasion which would result from excessive pressure differences across seals at the -upper and lower ends of the cavity H. In a similiar Vein the presence of the pressure balancing seal maximizes the operating life of the testing tool between tool overhaul periods.

The manner in which the pressure balancing seal serves to prevent the influx of cuttings or sediment into the cavity H efficiently prevents the clogging of the movement impeding, orifice coupling 9b.

Through the utilization of the mandrel in combination with upper and lower, separately telescoping, casing sections, and the pressure balancing seal, a uniquely effective double slide valve tester tool structure has resulted.

The incorporation of a hydraulic impedance coupling, having a pressure balancing seal, between the mandrel and one of two separately telescopable, casing sections affords positive and reliable means for attaining the controlled operation of one slide valve while another slide valve remains, in effect, substantially immobilized.

In particular, it should be noted that the operation of the tester valve, augmented by the pressure balancing seal, may be accomplished as often as possible by merely repeating linear upward and downward movements of the conduit string supporting the tester tool. An unexpectedly long operating life, which enables such sequential testing to be reliably performed, is attributable to the protective effect of the pressure balancing seal.

Another unexpected yet signicant advantage attributable to the pressure balancing seal involves the protection of the slidable block-type clutch contained within the reservoir H. In serving to keep debris out of the reservoir H, the pressure balancing seal protects the clutch blocks from becoming stuck or obstructed as a result of the accumulation of sediment or seal ycuttings in the clutch block or clutch groove area.

To those skilled in the art and familiar with this invention, additions, deletions, substitutions, and modifications with respect to the disclosed structure and operation techniques may readily occur. Such alterations, falling within the overall purview of this invention, are deemed to be encompassed wi-thin the scope of the appended claims.

I claim:

1. A submersible apparatus including a pressure balancing seal, said apparatus comprising:

reservoir means comprising rst and second portions and ladapted to be submerged in uid and contain fluid within its interior;

slide valve means carried by said reservoir means;

clutch means within said reservoir means, engaged with each of said first and second portions, and selectively operable to permit relative rotation between said first and second portions;

passage means adapted to provide pressure transmitting communication between uid within said reservoir means and uid outside of said reservoir means; and seal means movably mounted in said passage means asstra@ to tend to equalize the pressure of fluid Within said reservoir means and lfluid outside of said reservoir means. 2. An apparatus as vdescribed in claim 1: wherein said reservoir means includes a first generally tubular member, providing said first portion, and a second tubular member providing said second portion telescopingly received rwithin said iirst generally tubular member, said first and second generally tubular members having radially spaced portions defining a fluid cavity; wherein said seal means includes an annular, elastomeric., abradable seal disposed in said passage means for axial slidable movement therealong; and wherein said passage means includes an annular passage portion between said spaced portions of said first and second generally tubular members, at least one port in said first generally tubular member communicating with said annular passage portion and with the exterior of said first generally tubular member, and first and second abutment means disposed on opposite sides of said slidable annular seal and axially spaced within said annular passage portion. 3. An apparatus as described in claim 2: wherein said reservoir means additionally includes a fixed annular seal carried by one of said generally tubular members, sealingly and slideably engaging the other of said generally tubular members, and spaced axially from said axially slideable annular seal, with said axially slideable annular seal being disposed axially between said fixed annular seal and said annular passage portion, said fixed annular seal being adapted to communicate with uidwithin said reservoir means and uid outside of said first generally tubular member.

4. An apparatus as described in claim 3 and further including:

fluid ilow restricting, orifice means carried by one of said generally tubular members and disposed within said reservoir means axially between said fixed annular seal and said axially slideable annular seal.

5. An apparatus for controlling uid tiow within a well bore, said apparatus comprises:

a first portion;

a second portion upon which said first portion is mounted for limited telescoping movement;

a third portion upon which said second portion is mounted for limited telescoping movement;

first slide valve means carried by said first and said second portions;

second slide valve means carried by said second and said third portions;

reservoir means between said second and said third portions and adapted to be submerged in well uid and contain fluid within its interior;

passage means adapted to provide pressure transmitting communication between uid within said reservoir means and iuid outside of said reservoir means;

seal means movably mounted in said passage means to tend to equalize the pressure of iluid within said reservoir means and uid outside of said reservoir means;

movement impeding means interposed between said second portion and said third portion, located within said reservoir means, and adapted to impede, without preventing, relative telescoping movement of said second portion and said third portion whereby an axial force imposed upon said iirst portion and directed toward said third portion will tend to cause relative telescoping movement of said second and third portions induced by said imposed force; said third portion comprising a first generally tubular member; said second portion comprising a second tubular member telescopingly received within said first generally tubular member; said first and second generally tubular members having radially spaced portions defining a fiuid cavity of said reservoir means; said seal means including an annular, elastomeric, abradable seal disposed in said passage means for axial slidable movement therealong; and said passage means including an annular passage portion between said spaced portions of said first and second generally tubular members, at least one port in said first generally tubular member communicating with said annular passage portion and with the exterior of said first generally tubular member, and first and second abutment means disposed on opposite sides of said slidable annular seal and axially spaced within said annular passage portion; said reservoir means additionally including a fixed annular seal carried by one of said generally tubular members, sealingly and slidably engaging the other of said generally tubular members, and spaced axially from said axially suidable annular seal, with said axially slidable annular seal being disposed axially between said fixed annular seal and said annular passage portion, said fixed annular seal being adapted to communicate with fiuid within said reservoir means and fiuid outside of said first generally tubular member; and said movement impeding means including fluid fiow restricting, orifice means carried by one of said generally tubular members and disposed within said reservoir means axially between said fixed annular seal and said axially slidable annular seal; and clutch means contained within said reservoir means,

said clutch means including a plurality of axially slidable clutch blocks carried by one of said generally tubular members, axially extending clutch grooves on the other of said generally tubular members, and spring means biasing said clutch blocks into clutching relationship with said clutch grooves.

16 6. A submersible well apparatus, said apparatus coniprising:

a first tool portion;

a second tool portion;

means operable to anchor one of said first and second tool portions within a well bore;

means operable to extend from the other of said first and second tool portions to a well head and induce telescoping movement of said other tool portion relative to said one tool portion;

annular reservoir means interposed radially between said first and second tool portions and having axially spaced, first and second axial ends;

first and second abutment means carried in fixed positions on said first tool portion at One axial end of said reservoir means, and spaced axially thereof;

first seal means movably mounted on said first tool portion for limited axial movement between said rst and second abutment means, said first seal means being in sealing engagement with each of said first and second tool portions;

passage means operable to provide pressure-transmitting communication between well fiuid outside of said reservoir means and said seal means;

longitudinally extending passage means carried by said second tool portion and operable to contain flow restricting metering pin means;

second seal means at the Other axial end of Said reservoir means disposed in sealing engagement with said first and second tool portions;

passage exit means extending generally laterally of said longitudinally extending passage means and operable to provide fiuid communication between said passage means and said reservoir means; and

spline joint means interconnecting said first and second tool portions, said spline joint means being contained within said reservoir means between said first and second seal means.

References Cited UNITED STATES PATENTS 2,901,001 8/1959 Nutter 166-152 X 3,051,245 8/1962 Andrew et al 166--148 X 3,096,823 7/1963 Crowe 166-152 X 3,280,917 10/1966 Kisling 166-152 X DAVID H. BROWN, Primary Examiner.

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