Inflatable packer drill stem testing apparatus

Claim 2

Apparatus adapted for use in drill stem testing operations wherein normally retracted inflatable packer elements are expanded by pressurized fluid into sealing contact with the well bore wall in order to isolate an interval of the borehole, comprising: a body structure having concentrically disposed tubular members providing an annular inflation passage therebetween; a housing structure telescopically disposed over said body structure and movable upwardly and downwardly with respect thereto; means on said housing and body structures defining a chamber that is contracted in volume during upward movement of said housing structure, and expanded in volume during downward movement of said housing structure; first passage and valve means enabling said chamber to fill with fluid during said downward movement and being normally closed during said upward movement; and second passage and valve means for conducting pressurized fluid from said chamber to said inflation passage during said upward movement and being normally closed during said downward movement.

Claim 3

The apparatus of claim 1 wherein said first valve means comprises a downwardly opening check valve element at the upper end of said chamber, said element being sealingly slidable with respect to said housing structure and engageable with a valve seat carried by said body structure.

Claim 4

The apparatus of claim 2 wherein said second valve means comprises a sleeve member movable vertically with respect to said body structure between an upper open position and a lower closed position, said sleeve member providing a resultant transverse pressure surface that is subject on its lower side to the pressure of fluids in said chamber and on its upper side to the pressure of fluids in said inflation passage.

Claim 5

The apparatus of claim 3 further including spring means reacting between said valve element and said sleeve member for urging said valve element upwardly toward its closed position and said sleeve member downwardly toward its closed position.

Claim 6

The apparatus of claim 1 further including rotationally releasably clutch means for preventing upward movement of said housing structure relative to said body structure during lowering of said apparatus into the borehole.

Claim 7

The apparatus of claim 5 wherein said clutch means includes a threaded section of said body structure, a nut member threaded to said section and being slidably splined to said housing structure, whereby rotation of said housing structure relative to said body structure functions to feed said nut member along said body structure from a position preventing relative movement to a position permitting such relative movement.

Claim 8

Apparatus adapted for inflating an inflatable packer element in a borehole, comprising: an elongated body structure including concentrically disposed inner and outer tubular members providing a formation fluid flow passage through the center of said inner member and an annular inflation passage between said inner member and said outer member; an elongated housing structure disposed over said body structure and movable with respect thereto between an upper position and a lower position; said housing structure having an inwardly directed piston section that is sealingly slidable against an outer wall surface of said outer member and defining the lower wall of an annular working chamber extending longitudinally between said housing and body structures; a suction passage leading into the upper end of said chamber for conveying fluid thereto; a discharge passage proximate the upper end of said chamber for supplying fluid under pressure from said chamber to said inflation passage; first valve means for opening said suction passage during downward movement of said housing structure to enable said chamber to fill during such downward movement, said first valve means being normally closed during upward movement of said housing structure; and second valve means for closing said exhaust passage during downward movement of said housing structure and for opening said exhaust passage during upward movement to enable displacement of fluids under pressure from said chamber to said inflation passage during such upward movement.

Claim 9

Apparatus adapted for inflating an inflatable packer element in a borehole, comprising: an elongated body structure including concentrically disposed inner and outer tubular members providing a formation fluid flow passage through the center of said inner member and an annular inflation passage between said inner member and said outer member; an elongated housing structure disposed over said body structure and movable with respect thereto between an upper position and a lower position; said housing structure having an inwardly directed piston section that is sealingly slidable against an outer wall surface of said outer member and defining the lower wall of an annular working chamber extending longitudinally between said housing and body structures; a suction passage leading into the upper end of said chamber for conveying fluid thereto; a discharge passage proximate the upper end of said chamber for supplying fluid under pressure from said chamber to said inflation passage; first valve means for opening said suction passage during downward movement of said housing structure to enable said chamber to fill during such downward movement, said first valve means being normally closed during upward movement of said housing structure; and second valve means for closing said exhaust passage during downward movement of said housing structure and for opening said exhaust passage during upward movement to enable displacement of fluids under pressure from said chamber to said inflation passage during such upward movement.

Claim 10

The apparatus of claim 7 wherein said first valve means includes an annular valve element movably mounted on said body structure and sealingly slidable against an inner wall surface of said housing structure; said valve element coacting with a valve seat carried by said body structure and being movable downwardly away from said valve seat during downward movement of said housing structure and upwardly against said valve seat during upward movement of said housing structure.

Claim 11

The apparatus of claim 8 further including spring means for urging said valve element in an upward direction and against said valve seat.

Claim 12

The apparatus of claim 8 further including means for limiting the pressure that can be developed within said chamber during upward movement of said housing structure to correspondingly limit the magnitude of inflation pressure to be applied to said inflatable packer element.

Claim 13

The apparatus of claim 10 wherein said limiting means includes a vent passage leading from the upper end of said chamber, said valve seat being mounted for limited vertical movement with respect to said body structure, said vent passage being normally closed by coengageable means on said body structure and said valve seat; and yieldable means applying a selected closing force to said valve seat tending to maintain said coengageable means engaged, the development of a predetermined pressure within said chamber overcoming said yieldable means and forcing disengagement of said coengageable means to enable fluid to vent from said chamber via said vent passage.

Claim 14

The apparatus of claim 7 wherein said second valve means includes a valve sleeve movable vertically relative to said body structure between an open position and a closed position with respect to said discharge passage, spring means urging closing movement of said valve sleeve, and pressure responsive means for shifting said valve sleeve to its open position during upward movement of said housing structure.

Claim 15

The apparatus of claim 12 wherein said pressure responsive means includes a resultant transverse pressure surface with one side exposed to the pressure of fluids in said chamber and the other side exposed to the pressure of fluids in said inflation passage, whereby a greater pressure of fluids in said inflation passage acts together with said spring means to hold said valve sleeve closed, and a greater pressure of fluids in said chamber forces said valve sleeve against the bias afforded by said spring means to open position.

Claim 16

The apparatus of claim 7 wherein said suction passage extends from a location in communication with the well bore externally of said housing structure whereby said chamber is supplied with fluids from the well bore; and further including screen means for preventing the entry of debris in the well fluids into said suction passage.

Claim 17

Apparatus for use in inflating an inflatable packer element in a borehole, comprising: an elongated body structure providing a downwardly extending inflation passage arranged to convey fluid under pressure to said packer element; an elongated housing structure disposed in telescoping relation on said body structure and movable upwardly and downwardly with respect thereto between contracted and extended relative positions, intermediate portions of said body and housing structures being laterally spaced to define a first chamber means, said housing structure having an inwardly extending piston section that is sealingly slidable on an exterior surface of said body structure to define the lower end of said first chamber means; means on said body structure defining the upper end of said chamber means including first check valve means for admitting fluids into said first chamber means during downward movement of said housing structure, and second check valve means for enabling fluid under pressure to be exhausted from said first chamber means to said inflation passage during upward movement of said housing structure; second chamber means between said housing and body structures providing a suction passage leading to said first chamber means and being defined in part by an inwardly directed shoulder on said housing structure that is sealingly slidable on an exterior surface of said body structure that is of a lesser diameter than said first mentioned exterior surface, whereby said second chamber means has a greater lateral dimension than said first chamber means; and means for communicating said second chamber means with the well bore externally of said housing structure said second chamber means expanding to a greater volume during upward movement of said housing structure than the maximum volume of said first chamber means so that during downward movement of said housing structure an amount of well fluids equal to the difference in the volumes of said first and second chamber means is displaced via said communicating means to the well bore.

Claim 18

Apparatus for use in inflating an inflatable packer element in a borehole, comprising: an elongated body structure providing a downwardly extending inflation passage arranged to convey fluid under pressure to said packer element; an elongated housing structure disposed in telescoping relation on said body structure and movable upwardly and downwardly with respect thereto between contracted and extended relative positions, intermediate portions of said body and housing structures being laterally spaced to define a first chamber means, said housing structure having an inwardly extending piston section that is sealingly slidable on an exterior surface of said body structure to define the lower end of said first chamber means; means on said body structure defining the upper end of said chamber means including first check valve means for admitting fluids into said first chamber means during downward movement of said housing structure, and second check valve means for enabling fluid under pressure to be exhausted from said first chamber means to said inflation passage during upward movement of said housing structure; second chamber means between said housing and body structures providing a suction passage leading to said first chamber means and being defined in part by an inwardly directed shoulder on said housing structure that is sealingly slidable on an exterior surface of said body structure that is of a lesser diameter than said first mentioned exterior surface, whereby said second chamber means has a greater lateral dimension than said first chamber means; and means for communicating said second chamber means with the well bore externally of said housing structure said second chamber means expanding to a greater volume during upward movement of said housing structure than the maximum volume of said first chamber means so that during downward movement of said housing structure an amount of well fluids equal to the difference in the volumes of said first and second chamber means is displaced via said communicating means to the well bore.

Claim 19

The apparatus of claim 15 further including screen means for filtering out debris in the well fluids entering said communicating means, the displacement of said amount of well fluids from said second chamber means to the well bore during downward movement of said housing structure serving to backflush said screen means and maintain it clear of debris.

Claim 20

Apparatus adapted for isolating an interval of a borehole, comprising: packer means including at least one inflatable element; pump means for supplying fluid under pressure to said inflatable element to expand said element into sealing contact with a well bore wall; check valve means for trapping developed pressures within said element to maintain said element in sealing contact; first selectively operable means above said packer means including a normally closed valve for releasing said developed pressures to enable said element to deflate; and second selectively operable means below said packer means providing an additional valve for releasing said developed pressures to insure complete deflation of said element.

Claim 21

Apparatus adapted for isolating an interval of a borehole, comprising: packer means including at least one inflatable element; pump means for supplying fluid under pressure to said inflatable element to expand said element into sealing contact with a well bore wall; check valve means for trapping developed pressures within said element to maintain said element in sealing contact; first selectively operable means above said packer means including a normally closed valve for releasing said developed pressures to enable said element to deflate; and second selectively operable means below said packer means providing an additional valve for releasing said developed pressures to insure complete deflation of said element.

Claim 22

The apparatus of claim 17 wherein said first means includes inner and outer members arranged for longitudinal movement between mutually extended and contracted relative positions, said members defining a portion of an inflation passage leading from said pump means to said packer means, said valve being normally closed in the mutually contracted position of said member and open in the extended relative position.

Claim 23

The apparatus of claim 18 further including means for retarding longitudinal relative movement from said contracted position to said extended position to provide a time delay in the opening of said inflation passage.

Claim 24

The apparatus of claim 18 wherein said second means includes inner and outer members movable between mutually contracted and extended relative positions, said additional valve being closed in said contracted position and open in said extended position.

Claim 25

Valve apparatus disposed between a packer means including at least one inflatable element, and a pump means operable to supply fluid under pressure to said element to effect expansion thereof into sealing contact with a well bore wall, comprising: an inner body structure including concentric tubular members that are laterally spaced throughout their length to provide an annular inflation fluid passage; an outer body structure within which said inner body structure is movable from a mutually contracted relative position to a mutually extended relative position; and valve means on said body structures for opening said inflation passage to the exterior of said outer body structure in said mutually extended relative position and for preventing communication between said inflation passage and the exterior of said outer body structure in said mutually contracted position.

Claim 26

Valve apparatus disposed between a packer means including at least one inflatable element, and a pump means operable to supply fluid under pressure to said element to effect expansion thereof into sealing contact with a well bore wall, comprising: an inner body structure including concentric tubular members that are laterally spaced throughout their length to provide an annular inflation fluid passage; an outer body structure within which said inner body structure is movable from a mutually contracted relative position to a mutually extended relative position; and valve means on said body structures for opening said inflation passage to the exterior of said outer body structure in said mutually extended relative position and for preventing communication between said inflation passage and the exterior of said outer body structure in said mutually contracted position.

Claim 27

The apparatus of claim 21 wherein the inner one of said concentric tubular members has a hollow throughbore to provide a fluid flow passage; and further including an additional valve means operable only in said extended position of said body structures for communicating said throughbore with said inflation passage and thus with the exterior of said outer body structure.

Claim 28

The apparatus of claim 22 further including means for retarding longitudinal movement of said inner body structure relative to said outer body structure from said contracted position to said extended position to provide a time delay to opening of both of said valve means.

Claim 29

Apparatus for use in isolating an interval of a well bore, comprising: packer means including an inflatable element mounted on a body member and adapted to be expanded outwardly of said body member by fluid under pressure supplied to the interior of said element, said element when expanded coming into sealing contact with the surrounding well bore wall to isolate a region of the well bore from the hydrostatic pressure of fluids thereabove; and means for venting the pressures that may be developed in the well bore below said element during expansion thereof to the well bore above said element, including a fluid passage leading from said isolated interval to the well annulus above said element, and valve means for normally closing said fluid passage, said valve means having a transverse pressure area with one side exposed to the pressure of fluids in said passage and the opposite side exposed to the hydrostatic head of well bore fluids above said inflatable element in such a manner that a developed pressure within said passage in excess of said hydrostatic head will shift said valve means from closed to open position and thereby bleed off said excess pressure.

Claim 30

Apparatus for use in isolating an interval of a well bore, comprising: packer means including an inflatable element mounted on a body member and adapted to be expanded outwardly of said body member by fluid under pressure supplied to the interior of said element, said element when expanded coming into sealing contact with the surrounding well bore wall to isolate a region of the well bore from the hydrostatic pressure of fluids thereabove; and means for venting the pressures that may be developed in the well bore below said element during expansion thereof to the well bore above said element, including a fluid passage leading from said isolated interval to the well annulus above said element, and valve means for normally closing said fluid passage, said valve means having a transverse pressure area with one side exposed to the pressure of fluids in said passage and the opposite side exposed to the hydrostatic head of well bore fluids above said inflatable element in such a manner that a developed pressure within said passage in excess of said hydrostatic head will shift said valve means from closed to open position and thereby bleed off said excess pressure.

Claim 31

The apparatus of claim 24 further including means movable into contact with said valve means for shifting said valve means from said open position to said closed position.