Inflatable packer

Abstract

An improved inflatable packer is provided. In one embodiment, the improved packer has a tubular mandrel with an outer diameter essentially equal to the deflated inner diameter of an inflatable element surrounding the mandrel and has fluid flow passages that are adapted to cause at least a portion of pressurized fluid for inflating the element to be introduced into the annular space between the packer and the mandrel in a direction substantially parallel to the longitudinal axis of the tubular mandrel.

1 . An inflatable packer comprising: 
 (a) a tubular mandrel having a longitudinal axis;    (b) an inflatable element substantially concentrically disposed around said tubular mandrel, said inflatable element having a first end and a second end with each said end being sealingly attached to said tubular mandrel, and said inflatable element being adapted (i) to be inflated by introduction of pressurized fluid into an annular space between said inflatable element and said tubular mandrel and (ii) to be deflated by removal of said pressurized fluid from said annular space; and    (c) one or more fluid flow passages positioned substantially longitudinally along said tubular mandrel and extending through said annular space between said inflatable element and said tubular mandrel, which fluid flow passages are adapted to cause at least a portion of said pressurized fluid to be introduced into said annular space in a direction substantially parallel to said longitudinal axis of said tubular mandrel.    
   
   
       2 . The inflatable packer of  claim 1  wherein said tubular mandrel has an outer diameter that is substantially equal to the inner diameter of said inflatable element prior to inflation.  
   
   
       3 . The inflatable packer of  claim 1  wherein at least one of said fluid flow passages is formed by two or more grooves in said tubular mandrel.  
   
   
       4 . The inflatable packer of  claim 1  wherein said inflatable element comprises an outer elastomeric cover and a plurality of interconnected inner slats and, further, wherein at least a portion of said outer elastomeric cover has been removed such that at least a portion of said plurality of interconnected inner slats are exposed.  
   
   
       5 . An inflatable packer suitable for use under a pre-selected compressive load, said inflatable packer comprising: 
 (a) a tubular mandrel having a longitudinal axis, and    (b) an inflatable element substantially concentrically disposed around said tubular mandrel and adapted to provide pressure seals above and below said inflatable packer when inflated, and further said tubular mandrel having an outer diameter configured to prevent bending and buckling of said tubular mandrel under said pre-selected compressive load that results in failure of either of said pressure seals or of said inflatable packer and said tubular mandrel having one or more fluid flow passages positioned substantially longitudinally along said tubular mandrel and extending through an annular space between said inflatable element and said tubular mandrel.    
   
   
       6 . An inflatable packer suitable for use under a pre-selected external pressure, said inflatable packer comprising: 
 (a) a tubular mandrel having a longitudinal axis;    (b) an inflatable element comprising an inner bladder and an outer elastomeric cover and being substantially concentrically disposed around said tubular mandrel, said inflatable element having a first end and a second end with each said end being sealingly attached to said tubular mandrel, and said inflatable element being adapted (i) to be inflated by introduction of pressurized fluid into an annular space between said inflatable element and said tubular mandrel and (ii) to be deflated by removal of said pressurized fluid from said annular space;    (c) one or more fluid flow passages positioned substantially longitudinally along said tubular mandrel and extending through said annular space between said inflatable element and said tubular mandrel, wherein fluid flow passages are adapted to cause at least a portion of said pressurized fluid to be introduced into said annular space in a direction substantially parallel to said longitudinal axis of said tubular mandrel, and further said tubular mandrel having an outer diameter configured to prevent extrusion of said inner bladder into one or more of said fluid flow passages in said direction substantially parallel to said longitudinal axis of said tubular mandrel when said inflatable packer is subjected to said pre-selected external pressure.    
   
   
       7 . An inflatable packer comprising: 
 (a) a tubular mandrel having a longitudinal axis and one or more fluid flow passages positioned substantially longitudinally along said tubular mandrel, and    (b) an inflatable element comprising an inner bladder and an outer elastomeric cover and being substantially concentrically disposed around said tubular mandrel, said inflatable element having a first end and a second end with each said end being sealingly attached to said tubular mandrel, and said inflatable element being adapted (i) to be inflated by introduction of pressurized fluid into an annular space between said inflatable element and said tubular mandrel and (ii) to be deflated by removal of said pressurized fluid from said annular space, and further said tubular mandrel having an outer diameter configured to prevent folding of said inner bladder within said annular space between said inflatable element and said tubular mandrel.    
   
   
       8 . An inflatable packer comprising: 
 (a) a tubular mandrel having a longitudinal axis and one or more fluid flow passages positioned substantially longitudinally along said tubular mandrel, and    (b) an inflatable element comprising an outer elastomeric cover and a plurality of interconnected inner slats and being substantially concentrically disposed around said tubular mandrel, said inflatable element having a first end and a second end with each said end being sealingly attached to said tubular mandrel, and said inflatable element being adapted (i) to be inflated by introduction of pressurized fluid into an annular space between said inflatable element and said tubular mandrel and (ii) to be deflated by removal of said pressurized fluid from said annular space, and further wherein at least a portion of said elastomeric cover has been removed such that an appropriate length of said plurality of interconnected inner slats are exposed to minimize the deflated diameter of said inflatable element and to prevent loss of said outer elastomeric cover when said inflatable packer undergoes a plurality of inflation/deflation cycles.    
   
   
       9 . An inflatable packer suitable for use under a pre-selected internal pressure, said inflatable packer comprising: 
 (a) a tubular mandrel having a longitudinal axis and one or more fluid flow passages positioned substantially longitudinally along said tubular mandrel, and    (b) an inflatable element comprising an outer elastomeric cover, an inner bladder, and a plurality of interconnected inner slats and being substantially concentrically disposed around said tubular mandrel, said inflatable element having a first end and a second end with each said end being sealingly attached to said tubular mandrel, and said inflatable element being adapted (i) to be inflated by introduction of pressurized fluid into an annular space between said inflatable element and said tubular mandrel and (ii) to be deflated by removal of said pressurized fluid from said annular space, and further, wherein a portion of said outer elastomeric cover has been removed such that an appropriate length of said plurality of interconnected inner slats are exposed to prevent said exposed plurality of interconnected inner slats from damaging said inner bladder when said inflatable packer is subjected to said pre-selected internal pressure.    
   
   
       10 . An inflatable packer suitable for use under a pre-selected external pressure, said inflatable packer comprising: 
 (a) a tubular mandrel having a longitudinal axis;    (b) an inflatable element comprising an inner bladder and an outer elastomeric cover and being substantially concentrically disposed around said tubular mandrel, said inflatable element having a first end and a second end with each said end being sealingly attached to said tubular mandrel, and said inflatable element being adapted (i) to be inflated by introduction of pressurized fluid into an annular space between said inflatable element and said tubular mandrel and (ii) to be deflated by removal of said pressurized fluid from said annular space;    (c) one or more fluid flow passages positioned substantially longitudinally along said tubular mandrel and extending through said annular space between said inflatable element and said tubular mandrel, wherein fluid flow passages are adapted to cause at least a portion of said pressurized fluid to be introduced into said annular space in a direction substantially parallel to said longitudinal axis of said tubular mandrel, and wherein at least one of said fluid flow passages has at least one edge that is chamfered at an angle of about 40 degrees to about 50 degrees.    
   
   
       11 . An inflatable packer suitable for use under a pre-selected external pressure, said inflatable packer having a fixed end and a floating end and comprising: 
 (a) a tubular mandrel having a longitudinal axis;    (b) an inflatable element comprising an inner bladder and an outer elastomeric cover and being substantially concentrically disposed around said tubular mandrel, said inflatable element having a first end and a second end with each said end being sealingly attached to said tubular mandrel, and said inflatable element being adapted (i) to be inflated by introduction of pressurized fluid into an annular space between said inflatable element and said tubular mandrel and (ii) to be deflated by removal of said pressurized fluid from said annular space;    (c) one or more fluid flow passages positioned substantially longitudinally along said tubular mandrel and extending through the annular space between said inflatable element and said tubular mandrel, which fluid flow passages are adapted to cause at least a portion of said pressurized fluid to be introduced into said annular space in a direction substantially parallel to said longitudinal axis of said tubular mandrel; and    (d) at least one device adjacent said fixed end, said device being adapted to prevent extrusion of said inner bladder into one or more of said fluid flow passages in a direction substantially parallel to said longitudinal axis of said tubular mandrel when said packer is subjected to said pre-selected external pressure.    
   
   
       12 . The inflatable packer of  claim 3 , further comprising a screen in the form of a cylindrical sleeve sized to fit around said tubular mandrel, said screen having holes to allow fluid flow but prevent extrusion of said inflatable element during deflation of said inflatable packer.  
   
   
       13 . The inflatable packer of  claim 12 , wherein said screen sleeve is confined on said tubular mandrel axially by a diameter upset on said tubular mandrel at one end, and a removable securing device at the other end.  
   
   
       14 . A method comprising: 
 providing an inflatable packer comprising a tubular mandrel having a longitudinal axis and one or more fluid flow passages positioned substantially longitudinally along said tubular mandrel, and an inflatable element substantially concentrically disposed around said tubular mandrel, said inflatable element having a first end and a second end with each said end being sealingly attached to said tubular mandrel, and said inflatable element being adapted (i) to be inflated by introduction of pressurized fluid into an annular space between said inflatable element and said tubular mandrel and (ii) to be deflated by removal of said pressurized fluid from said annular space; and    disposing said inflatable packer into a wellbore.    
   
   
       15 . The method of  claim 14 , wherein said one or more fluid flow passages are adapted to cause at least a portion of said pressurized fluid to be introduced into said annular space in a direction substantially parallel to said longitudinal axis of said tubular mandrel.  
   
   
       16 . The method of  claim 14  wherein said tubular mandrel has an outer diameter that is substantially equal to the inner diameter of said inflatable element prior to inflation.  
   
   
       17 . The method of  claim 14  comprising defining at least one of said fluid flow passages to be formed by two or more grooves in said tubular mandrel.  
   
   
       18 . The method of  claim 14  wherein said inflatable element comprises an outer elastomeric cover and a plurality of interconnected inner slats and, further, wherein at least a portion of said outer elastomeric cover has been removed such that at least a portion of said plurality of interconnected inner slats are exposed.  
   
   
       19 . The method of  claim 18  comprising configuring a portion of said outer elastomeric cover has been removed such that an appropriate length of said plurality of interconnected inner slats are exposed to prevent said exposed plurality of interconnected inner slats from damaging said inner bladder when said inflatable packer is subjected to said pre-selected internal pressure.  
   
   
       20 . The method of  claim 14  comprising configuring said inflatable packer to have an outer diameter suitably large to prevent bending and buckling of said tubular mandrel under said pre-selected compressive load that results in failure of either of said pressure seals or of said inflatable packer.  
   
   
       21 . The method of  claim 14  comprising configuring said tubular mandrel to have having an outer diameter suitably large to prevent extrusion of said inner bladder into said one or more of said fluid flow passages in said direction substantially parallel to said longitudinal axis of said tubular mandrel when said inflatable packer is subjected to said pre-selected external pressure.  
   
   
       22 . The method of  claim 14  wherein at least one of said fluid flow passages has at least one edge chamfered at an angle of about 40 degrees to about 50 degrees.  
   
   
       23 . The method of  claim 14  comprising expanding said inflatable packer to seal a portion of said wellbore.  
   
   
       24 . The method of  claim 23  comprising producing hydrocarbons from said wellbore by utilizing said expanded inflatable packer.