Positive displacement apparatus for selectively translating expander tool downhole

Abstract

The present invention provides a positive displacement apparatus for selectively translating a completion tool, such as an expander tool, downhole. The positive displacement apparatus comprises a set of three essentially concentric tubular members. The three tubulars represent (1) an outer sleeve, (2) an inner mandrel, and (3) a middle displacement piston between the sleeve and the mandrel. These three tubular members are nested within the expandable liner or other tubular to be expanded within a wellbore. A fluid transfer chamber is provided below the middle displacement piston. Rotation of the positive displacement apparatus serves to draw fluid into the fluid transfer chamber. This fluid, in turn, is pumped into a fluid transfer channel and forces the displacement piston upward between the outer sleeve and the inner mandrel. The displacement piston then acts against the rotary expander tool. In this manner, the displacement piston translates the rotary expander tool axially within the wellbore.

1 . An apparatus for translating an expander tool axially within a wellbore in order to facilitate the expansion of a first tubular into a surrounding second tubular, the apparatus comprising: 
 a fluid chamber having a first end and a second end;    a displacement piston having a first end and a second end, the first end of the displacement piston acting upon the expander tool, and the second end being in communication with the fluid chamber;    a rotor piston having a first end and a second end, the first end of the rotor piston sealingly residing within the fluid chamber; and    the fluid chamber sized and configured such that reciprocal movement of the rotor piston causes axial movement of the displacement piston within the wellbore.    
     
     
         2 . The apparatus of  claim 1 , further comprising a fluid medium that is applied under pressure against the second end of the displacement piston in order to translate the expander tool within the wellbore.  
     
     
         3 . The apparatus of  claim 2 , wherein the first tubular defines a lower string of casing, and the second tubular defines an upper string of casing.  
     
     
         4 . The apparatus of  claim 3 , wherein 
 the rotor piston has a bottom face at its second end, the bottom face having a wave form configuration; and    the first end of the rotor piston is reciprocated axially within the fluid transfer chamber by rotating the rotor piston.    
     
     
         5 . The apparatus of  claim 4 , 
 further comprising a stator member, the stator member having a top face having a wave form configuration; and    wherein the bottom face of the rotor piston rides on the top face of the stator member such that rotation of the rotor piston causes the rotor piston to reciprocate axially.    
     
     
         6 . The apparatus of  claim 5 , wherein the stator member is stationary within the wellbore while the rotor piston is being rotated.  
     
     
         7 . The apparatus of  claim 6 , further comprising a biasing member disposed in the fluid chamber, the biasing member biasing the rotor piston to ensure essentially continuous contact between the bottom face of the rotor piston and the top face of the stator member.  
     
     
         8 . The apparatus of  claim 7 , further comprising: 
 an inner mandrel, the inner mandrel defining a tubular body nested essentially concentrically within the displacement piston;    an outer sleeve, the outer sleeve defining a tubular body surrounding the displacement piston such that the displacement piston is nested essentially concentrically within the outer sleeve; and    wherein the fluid medium is loaded in an annular region defined between the expandable first tubular and the outer sleeve.    
     
     
         9 . The apparatus of  claim 8 , further comprising: 
 an annular feed channel placing the annular region and the fluid chamber in fluid communication;    an inflow valve permitting fluid to flow from the annular region into the fluid chamber; and    an outflow valve permitting fluid to flow from the fluid chamber against the second end of the displacement piston in response to rotational movement of the rotor piston.    
     
     
         10 . The apparatus of  claim 9 , wherein the displacement piston is connected to the outer sleeve by a splined connection, allowing the displacement piston to move axially relative to the outer sleeve.  
     
     
         11 . The apparatus of  claim 10 , wherein the displacement piston is connected to the inner mandrel by a splined connection, allowing the displacement piston to move axially relative to the inner mandrel.  
     
     
         12 . The apparatus of  claim 9 , further comprising at least one seal at the first end of the rotor piston to provide a fluid seal between the rotor piston and the fluid chamber.  
     
     
         13 . The apparatus of  claim 12 , further comprising at least one seal at the second end of the displacement piston to provide a fluid seal between the displacement piston and the inner mandrel on an inner surface of the displacement piston, and between the displacement piston and the outer sleeve on an outer surface of the displacement piston.  
     
     
         14 . An apparatus for translating an expander tool axially within a wellbore in order to facilitate the expansion of an upper portion of a liner string into a surrounding string of casing, the apparatus comprising: 
 a fluid transfer chamber having an upper end and a lower end;    a displacement piston having an upper end and a lower end, the upper end of the displacement piston acting upon the expander tool, and the lower end being in communication with the fluid chamber;    an inner mandrel, the inner mandrel defining a tubular body nested essentially concentrically within the displacement piston;    an outer sleeve, the outer sleeve defining a tubular body surrounding the displacement piston such that the displacement piston is nested essentially concentrically within the outer sleeve;    a rotor piston having an upper end and a lower end, the upper end of the rotor piston sealingly residing within the fluid transfer chamber;    oil, the oil loaded in an annular region defined between the expandable liner string and the outer sleeve;    an annular feed channel placing the annular region and the fluid chamber in fluid communication;    an inflow valve permitting the oil to flow from the annular region into the fluid chamber;    an outflow valve permitting the oil to flow from the fluid chamber against the lower end of the displacement piston in response to rotational movement of the rotor piston; and    the fluid chamber sized and configured such that reciprocal movement of the rotor piston causes axial movement of the displacement piston within the wellbore.    
     
     
         15 . The apparatus of  claim 14 , wherein the rotor piston has a bottom face at its lower end, the bottom face having a wave form configuration; 
 the second end of the rotor piston is reciprocated axially within the fluid transfer chamber by rotating the rotor piston;    
     
     
         16 . The apparatus of  claim 15 , further comprising a stationary stator member, the stator member having a top face having a wave form configuration; and 
 wherein the bottom face of the rotor piston rides on the top face of the stator member such that rotation of the rotor piston imparts an upstroke and a downstroke to the rotor piston, causing the rotor piston to reciprocate axially within the fluid transfer chamber such that oil is drawn into the fluid transfer chamber on the downstroke of the rotor piston, and oil is extruded under pressure against the displacement piston on the upstroke, thereby imparting axial movement to the displacement piston and to the expander tool within the wellbore.    
     
     
         17 . The apparatus of  claim 16 , further comprising a spring disposed in the fluid transfer chamber, the spring biasing the rotor piston to ensure essentially continuous contact between the bottom face of the rotor piston and the top face of the stator member.  
     
     
         18 . The apparatus of  claim 17 , wherein the displacement piston moves axially relative to the outer sleeve.  
     
     
         19 . The apparatus of  claim 18 , wherein the displacement piston moves axially relative to the inner mandrel.  
     
     
         20 . The apparatus of  claim 15 , 
 further comprising a stationary stator member, the stator member having a top face having a wave form configuration; and    wherein the bottom face of the rotor piston rides on the top face of the stator member such that rotation of the rotor piston imparts a downstroke and an upstroke to the rotor piston, causing the rotor piston to reciprocate axially within the fluid transfer chamber such that oil is drawn into the fluid transfer chamber on the upstroke of the rotor piston, and oil is extruded under pressure against the displacement piston on the downstroke, thereby imparting axial movement to the displacement piston and to the expander tool within the wellbore.    
     
     
         21 . An apparatus for translating an expander tool axially within a wellbore in order to facilitate the expansion of an upper portion of a liner string into a surrounding string of casing, the apparatus comprising: 
 a fluid transfer chamber having an upper end and a lower end;    a displacement piston having an upper end and a lower end, the upper end of the displacement piston acting upon the expander tool, and the lower end being in communication with the fluid chamber;    a rotor piston having an upper end and a lower end, the upper end of the rotor piston sealingly residing within the fluid transfer chamber, and the lower end having a bottom face, the bottom face having a wave form configuration;    a spring disposed in the fluid transfer chamber, the spring biasing the rotor piston to ensure essentially continuous contact between the bottom face of the rotor piston and the top face of the stator member;    a stator having an upper face having a wave form configuration which mates with the bottom face of the rotor piston; and    wherein the bottom face of the rotor piston rides on the top face of the stator member such that rotation of the rotor piston imparts an upstroke and a downstroke to the rotor piston, causing the rotor piston to reciprocate axially within the fluid transfer chamber such that oil is drawn into the fluid transfer chamber on the downstroke of the rotor piston, and oil is extruded under pressure against the displacement piston on the upstroke, thereby imparting axial movement to the displacement piston and to the expander tool within the wellbore.    
     
     
         22 . The apparatus of  claim 21 , further comprising a plurality of check valves, the check valves being constructed and arranged to allow the oil to enter the fluid transfer chamber on the downstroke of the rotor piston, and to exit the fluid transfer chamber on the upstroke of the rotor piston.  
     
     
         23 . The apparatus of  claim 22 , further comprising a plurality of check valves, the check valves being constructed and arranged to allow the oil to enter the fluid transfer chamber on the upstroke of the rotor piston, and to exit the fluid transfer chamber on the downstroke of the rotor piston.  
     
     
         24 . The apparatus of  claim 22 , further comprising: 
 an inner mandrel, the inner mandrel defining a tubular body nested essentially concentrically within the displacement piston;    an outer sleeve, the outer sleeve defining a tubular body surrounding the displacement piston such that the displacement piston is nested essentially concentrically within the outer sleeve; and    wherein the fluid medium is loaded in an annular region defined between the expandable liner string and the outer sleeve.