Hydraulically set liner hanger

Abstract

A liner hanger, in either a non-rotating or rotating format, has a large hanging capacity due to a one or more axially spaced sets of circumferentially spaced slips housed in openings in a slip housing, the slip housing being moveable axially relative to a mandrel for actuating the slips over cams supported by the mandrel. One or more sets of sets of slips are spaced axially along the slip housing. An annular space is formed between the mandrel and slip housing for maximizing fluid bypass through the annular space. Bypass is further improved by profiling the slip housing. In the rotating version, a separate sleeve is positioned between the mandrel and the slip housing for supporting the cams and the mandrel is supported on the cam sleeve through an upper bearing which permits the mandrel to rotate on the cam sleeve when the slips are set.

The embodiments of the invention in which and exclusive property or priviledge is claimed are defined as follows:  
     
         1 . A liner hanger for use in hanging a liner inside an existing casing in a wellbore, the liner hanger comprising: 
 a tubular mandrel having a slip housing mounted thereon and defining an annular space therebetween, the slip housing being axially moveable upon the mandrel and having an inlet and an outlet for permitting the flow of fluids through the annular space;    one or more sets of circumferentially spaced slips, each slip being housed in a slip opening in the slip housing, each of the one or more sets of slips being spaced axially along the slip housing,    cam surfaces supported by and extending radially outward from the mandrel and corresponding with each slip;    a spring for biasing each slip to a radially stowed position towards the mandrel; and    an actuator attached to the mandrel for axially moving the slip housing and engaging the slips with the cam surfaces for causing the slips to move from the radially stowed position to a radially extended position for engaging the existing casing.    
     
     
         2 . The liner hanger as described in  claim 1  wherein the slip housing is profiled so as to enlarge the annular space and thereby increase fluid flow bypass.  
     
     
         3 . The liner hanger as described in  claim 1  wherein the spring is connecting between the slip housing and each slip.  
     
     
         4 . The liner hanger as described in  claim 1  wherein the spring is a flat spring secured to each slip and extending either side of the slip opening for connecting between the slip housing and each slip.  
     
     
         5 . The liner hanger as described in  claim 1  wherein the cam faces are integral with the mandrel.  
     
     
         6 . The liner hanger as described in  claim 1  wherein the actuator is a hydraulic portion comprising: 
 a tubular piston housing formed on the mandrel and defining an cylindrical space therebetween; and  
 a piston positioned within the cylindrical space and axially moveable therein, the piston being in fluid communication with a bore of the mandrel for actuating the piston from a non-actuated, downhole position to an uphole actuated position as a result of pressure increases in the bore of the mandrel.  
 
     
     
         7 . The liner hanger as described in  claim 1  further comprising a shear screw connected between the mandrel and the slip housing so as to prevent axial movement of the slip housing during insertion of the liner hanger into the wellbore.  
     
     
         8 . The liner hanger as described in  claim 1  further comprising a collet system between the mandrel and the slip housing for temporarily retaining the slip housing in a downhole non-actuated position during insertion of the liner hanger into the wellbore.  
     
     
         9 . The liner hanger as described in  claim 8  wherein the collet system comprises: 
 a collet connected to the slip housing and normally engaged in a corresponding profile on the mandrel;  
 a collet housing adapted to the slip housing and forming an annular space between the collet and the collet housing;  
 a collet retainer positioned in the annular space in a downhole position for retaining the collet in the profile in the mandrel and axially moveable therein to an uphole position for releasing the collet from the profile in the mandrel; and  
 a shear screw between the collet retainer and the collet housing for temporarily restraining the collet retainer in the downhole position.  
 
     
     
         10 . The liner hanger as described in  claim 9  wherein the collet retainer further comprises a profiled inner surface for alignment with the collet when the collet retainer is moved axially uphole and accepting the collet when released radially from the profile in the mandrel  
     
     
         11 . The liner hanger as described in  claim 1  further comprising mechanical supports formed on either side of the opening in the slip housing at a downhole end of the slips for further supporting the slips in the extended position.  
     
     
         12 . The liner hanger as described in  claim 11  wherein the supports are tabs having slits formed in the housing above and below each tab, at an interface between the tab and the slip housing to ensure bending of the tab under stress  
     
     
         13 . The liner hanger as described in  claim 1  wherein the slip housing further comprises a plurality of additional openings therethrough to improve fluid bypass.  
     
     
         14 . The liner hanger as described in  claim 1  further comprising: 
 a cam sleeve positioned between the mandrel and the slip housing and defining the annular space between the cam sleeve and slip housing, the cam surfaces extending radially outward from the cam sleeve; and  
 an upper bearing for supporting the mandrel on the cam sleeve while permitting the mandrel to rotate relative to the cam sleeve and slip housing when the slips engage the casing.  
 
     
     
         15 . The liner hanger as described in  claim 14  wherein the slip housing is profiled so as to enlarge the annular space and thereby increase fluid flow bypass.  
     
     
         16 . The liner hanger as described in  claim 14  wherein the spring is a flat spring secured to each slip and extending either side of the opening for connecting between the slip housing and the slip.  
     
     
         17 . The liner hanger as described in  claim 14  wherein the actuator is a hydraulic portion comprising: 
 a tubular piston housing formed on the mandrel and defining an cylindrical space therebetween;  
 a piston positioned within the cylindrical space and axially moveable therein, the piston being in fluid communication with a bore of the mandrel for actuating the piston from a non-actuated, downhole position to an uphole actuated position as a result of pressure increases in the bore of the mandrel; and  
 a shear screw connected between the mandrel and the slip housing so as to prevent axial movement of the slip housing during insertion of the liner hanger into the wellbore.  
 
     
     
         18 . A liner hanger for use in hanging a liner inside an existing casing in a wellbore, the liner hanger comprising: 
 a tubular mandrel having a slip housing mounted thereon and defining an annular space therebetween, the slip housing being axially moveable upon the mandrel and having an inlet and an outlet for permitting the flow of fluids through the annular space;    two or more sets of circumferentially spaced slips, each slip being housed in a slip opening in the slip housing, each of the two or more sets of slips being spaced axially along the slip housing,    cam surfaces extending radially outward from the mandrel and corresponding with each slip;    a spring for biasing each slip to a radially stowed position towards the mandrel; and    an actuator attached to the mandrel for axially moving the slip housing and engaging the slips with the cam surfaces for causing the slips to move from the radially stowed position to a radially extended position for engaging the existing casing.    
     
     
         19 . The liner hanger as described in  claim 18  wherein the slip housing is profiled so as to enlarge the annular space and thereby increase fluid flow bypass.  
     
     
         20 . The liner hanger as described in  claim 18  wherein the spring is a flat spring secured to each slip and extending either side of the opening for connecting between the slip housing and the slip.  
     
     
         21 . The liner hanger as described in  claim 18  wherein the actuator is a hydraulic portion comprising: 
 a tubular piston housing formed on the mandrel and defining an cylindrical space therebetween;  
 a piston positioned within the cylindrical space and axially moveable therein, the piston being in fluid communication with a bore of the mandrel for actuating the piston from a non-actuated, downhole position to an uphole actuated position as a result of pressure increases in the bore of the mandrel; and  
 a shear screw connected between the mandrel and the slip housing so as to prevent axial movement of the slip housing during insertion of the liner hanger into the wellbore.  
 
     
     
         22 . The liner hanger as described in  claim 18  further comprising a collet system for temporarily retaining the slip housing in a downhole non-actuated position during insertion of the liner hanger into the wellbore, wherein the collet system comprises: 
 a collet connected to the slip housing and normally engaged in a corresponding profile on the mandrel;  
 a collet housing adapted to the slip housing and forming an annular space between the collet and the collet housing;  
 a collet retainer positioned in the annular space in a downhole position for retaining the collet in the profile in the mandrel and axially moveable therein to an uphole position for releasing the collet from the profile in the mandrel; and  
 a shear screw between the collet retainer and the collet housing for temporarily restraining the collet retainer in the downhole position.  
 
     
     
         23 . The liner hanger as described in  claim 18  further comprising: 
 a cam sleeve positioned between the mandrel and the slip housing and defining the annular space between the cam sleeve and slip housing, the cam surfaces extending radially outward from the cam sleeve; and  
 an upper bearing for supporting the mandrel on the cam sleeve while permitting the mandrel to rotate relative to the cam sleeve and slip housing when the slips engage the casing.  
 
     
     
         24 . The liner hanger as described in  claim 23  wherein the slip housing is profiled so as to enlarge the annular space and thereby increase fluid flow bypass.  
     
     
         25 . The liner hanger as described in  claim 23  wherein the spring is a flat spring secured to each slip and extending either side of the opening for connecting between the slip housing and the slip.  
     
     
         26 . The liner hanger as described in  claim 23  wherein the actuator is a hydraulic portion comprising: 
 a tubular piston housing formed on the mandrel and defining an cylindrical space therebetween;  
 a piston positioned within the cylindrical space and axially moveable therein, the piston being in fluid communication with a bore of the mandrel for actuating the piston from a non-actuated, downhole position to an uphole actuated position as a result of pressure increases in the bore of the mandrel; and  
 a shear screw connected between the mandrel and the slip housing so as to prevent axial movement of the slip housing during insertion of the liner hanger into the wellbore.  
 
     
     
         27 . A liner hanger for use in hanging a liner inside an existing casing in a wellbore, the liner hanger comprising: 
 a tubular mandrel having a slip housing mounted thereon, the slip housing being axially moveable relative to the mandrel;    one or more sets of circumferentially spaced slips, each slip being housed in a slip opening in the slip housing, each of the one or more sets of slips being spaced axially along the slip housing,    a cam sleeve positioned between the mandrel and the slip housing and defining an annular space between the cam sleeve and slip housing, the annular space having an inlet and an outlet for permitting the flow of fluids through the annular space, the cam sleeve having cam surfaces extending radially outward for urging the slips on the slip housing to a radially extended position;    an upper bearing for supporting the mandrel on the cam sleeve while permitting the mandrel to rotate relative to the cam sleeve and slip housing when the slips engage the casing; and    an actuator acting between the mandrel and the slip housing for axially moving the slip housing and engaging the slips with the cam surfaces for causing the slips to move from a radially stowed position to a radially extended position for engaging the existing casing.    
     
     
         28 . The liner hanger as described in  claim 27  further comprising a spring for biasing each slip to a radially stowed position towards the mandrel.  
     
     
         29 . The liner hanger as described in  claim 27  wherein the slip housing is profiled so as to enlarge the annular space therebetween and increase fluid flow bypass.  
     
     
         30 . The liner hanger as described in  claim 27  wherein the actuator is a hydraulic portion comprising: 
 a tubular piston housing formed on the mandrel and defining an cylindrical space therebetween; and  
 a piston positioned within the cylindrical space and axially moveable therein, the piston being in fluid communication with a bore of the mandrel for actuating the piston from a non-actuated, downhole position to an uphole actuated position as a result of pressure increases in the bore of the mandrel.  
 
     
     
         31 . The liner hanger as described in  claim 27  further comprising a shear screw connected between the mandrel and the slip housing so as to prevent axial movement of the slip housing during insertion of the liner hanger into the wellbore.  
     
     
         32 . The liner hanger as described in  claim 27  wherein the upper bearing supporting the cam sleeve is a taper bearing.  
     
     
         33 . The liner hanger as described in  claim 27  further comprising a collet system between the mandrel and slip housing for retaining the slip housing in a downhole non-actuated position during insertion of the liner hanger into the wellbore.  
     
     
         34 . The liner hanger as described in  claim 33  wherein the collet system comprises: 
 a collet connected to the slip housing and normally engaged in a corresponding profile on the mandrel;  
 a collet housing adapted to the slip housing and forming an annular space between the collet and the collet housing;  
 a collet retainer positioned in the annular space in a downhole position for retaining the collet in the profile in the mandrel and axially moveable therein to an uphole position for releasing the collet from the profile in the mandrel; and  
 a shear screw between the collet retainer and the collet housing for temporarily restraining the collet retainer in the downhole position.  
 
     
     
         35 . The liner hanger as described in  claim 34  wherein the collet retainer further comprises a profiled inner surface for alignment with the collet when the collet retainer is moved axially uphole and accepting the collet when released radially from the profile in the mandrel.  
     
     
         36 . The liner hanger as described in  claim 27  further comprising mechanical supports formed on either side of the opening in the slip housing at a downhole end of the slips for further supporting the slips in the extended position.  
     
     
         37 . The liner hanger as described in  claim 36  wherein the supports are formed as tabs further comprising slits formed in the housing above and below each tab at an interface between the tab and the slip housing to ensure bending of the tab under stress.  
     
     
         38 . The liner hanger as described in  claim 27  wherein the slip housing further comprises a plurality of additional openings therethrough to improve fluid bypass.  
     
     
         39 . The liner hanger as described in  claim 27  having two or more sets of circumferentially spaced slips, housed in a plurality of openings in the slip housing, each of the one or more sets of slips being spaced axially along the slip housing.