Pumping sub for well logging tools

Abstract

The pumping sub comprises first and second inflatable bladders which are pressurized to inflate to accommodate various pipe diameters. Pressure relief value means is provided to assist in clearing obstructions within the pipe. The pumping sub acts as a parachute to slow the fall of a logging tool and enables the logging tool to be pumped up and down a drill pipe. FIG. 4

1 . A pumping sub for use in a drill pipe, said pumping sub comprising inflatable bladder means, said inflatable bladder means being adapted to expand to conform to the diameter of a drill pipe when inserted into said drill pipe.  
     
     
         2 . A pumping sub as claimed in    claim 1    in which the inflatable bladder means comprises an inner inflatable bladder situated within a cage of spring wires and in which internal pressure within said bladder causes said spring wires to move outwardly with increase in size of said bladder to conform to the internal diameter of a drill pipe into which said pumping sub is inserted.  
     
     
         3 . A pumping sub as claimed in    claim 1    in which the inflatable bladder means comprises an inner inflatable bladder situated within a cage of spring wires and in which internal pressure within said bladder causes said spring wires to move outwardly with increase in size of said bladder to conform to the internal diameter of a drill pipe into which said pumping sub is inserted; and in which said bladder is provided with piston means operative to supply pressurized fluid to said bladder to inflate said bladder.  
     
     
         4 . A pumping sub as claimed in    claim 1    in which the inflatable bladder means comprises an inner inflatable bladder situated within a cage of spring wires and in which internal pressure within said bladder causes said spring wires to move outwardly with increase in size of said bladder to conform to the internal diameter of a drill pipe into which said pumping sub is inserted; in which said bladder is provided with piston means operative to supply pressurized fluid to said bladder to inflate said bladder; and in which said piston means is situated within a cylinder and said piston means is provided with spring means creating pressure on said piston means, in which said cylinder means is filled with fluid and in which said cylinder means is connected to said bladder means thereby to create continual pressure within said bladder means.  
     
     
         5 . A pumping sub as claimed in    claim 1    in which the inflatable bladder means comprises an inner inflatable bladder situated within a cage of spring wires and in which internal pressure within said bladder causes said spring wires to move outwardly with increase in size of said bladder to conform to the internal diameter of a drill pipe into which said pumping sub is inserted; in which said bladder is provided with piston means operative to supply pressurized fluid to said bladder to inflate said bladder; in which said piston means is situated within a cylinder and said piston means is provided with spring means creating pressure on said piston means, in which said cylinder means is filled with fluid; in which said cylinder means is connected to said bladder means thereby to create continual pressure within said bladder means; and in which said piston means is situated at first end of said bladder means.  
     
     
         6 . A pumping sub as claimed in    claim 1    in which the inflatable bladder means comprises an inner inflatable bladder situated within a cage of spring wires and in which internal pressure within said bladder causes said spring wires to move outwardly with increase in size of said bladder to conform to the internal diameter of a drill pipe into which said pumping sub is inserted; in which said bladder is provided with piston means operative to supply pressurized fluid to said bladder to inflate said bladder; in which said piston means is situated within a cylinder and said piston means is provided with spring means creating pressure on said piston means, in which said cylinder means is filled with fluid; in which said cylinder means is connected to said bladder means thereby to create continual pressure within said bladder means; in which said piston means is situated at first end of said bladder means; and in which mud flow inlet means is provided adjacent to said piston means to allow mud flow pass said piston means and passageway means is provided through a central portion of said bladder means and connected to said mud flow inlet means to allow mud to flow through the bladder means, and in which said passage means is connected to relief valve means operative to allow passage of mud through said mud flow inlet means and said passageway means when said mud flow pressure exceeds a maximum value.  
     
     
         7 . A pumping sub as claimed in    claim 1    in which the inflatable bladder means comprises an inner inflatable bladder situated within a cage of spring wires and in which internal pressure within said bladder causes said spring wires to move outwardly with increase in size of said bladder to conform to the internal diameter of a drill pipe into which said pumping sub is inserted, wherein the inflatable bladder is a hollow member having an opening at either end, tie bladder being secured, about the periphery of each said opening, to a housing, by means of an anchoring collar that grips the bladder and secures it relative to the housing.  
     
     
         8 . A pumping as claimed in    claim 1    in which the inflatable bladder means comprises an inner inflatable bladder situated within a cage of spring wires and in which internal pressure within said bladder causes said spring wires to move outwardly with increase in size of said bladder to conform to the internal diameter of a drill pipe into which said pumping sub is inserted, wherein the inflatable bladder is a hollow member having an opening at either end, the bladder being secured, about the periphery of each said opening, to a housing, by means of an anchoring collar that grips the bladder and secures it relative to the housing; and wherein each said spring wire is received at each end in a respective aperture in a said anchoring collar, each said aperture defining a shoulder facing away from the bladder and each said spring wire including secured thereto a portion lying to the side of the shoulder remote from the bladder and so shaped and/or dimensioned as to be incapable of passing beyond the shoulder towards the bladder, whereby the spring wire is slidably captive relative to the anchoring collar.  
     
     
         9 . A pumping sub as claimed in any one of claims  1  in which the inflatable bladder means comprises an inner inflatable bladder situated within a cage of spring wires and in which internal pressure within said bladder causes said spring wires to move outwardly with increase in size of said bladder to conform to the internal diameter of a drill pipe into which said pumping sub is inserted, wherein said pumping sub comprises two said inflatable bladder means mounted in tandem but with opposite bands, each said bladder means being provided with mud flow inlet means and passageway means, said passageway means each being provided with relief valve means.  
     
     
         10 . A pumping sub as claimed in    claim 1    in which the inflatable bladder means comprises and inner inflatable bladder situated within a cage of spring wires and in which internal pressure within said bladder causes said spring wires to move outwardly with increase in size of said bladder to conform to the internal diameter of a drill pipe into which said pumping sub is inserted; wherein said pumping sub comprises two inflatable bladder means mounted in tandem but with opposite hands, each said bladder means being provided with mud flow inlet means and passageway means, said passageway means each being provided with relief valve means; and in which said relief valve means for said two inflatable means are combined into a single bi-directional relief valve means.  
     
     
         11 . An apparatus for inserting an inflated pumping sub into a fluid filled drill pipe, the apparatus including a hollow, generally cylindrical sleeve of smaller outer diameter than the internal diameter of a drill pipe and into which the pumping sub is insertable via an opening at an in use lower end thereof, an upper portion of the sleeve including one or more passages providing fluid communication between the interior and exterior of the sleeve whereby on insertion of a said sleeve containing a said pumping sub into a said drill pipe, so that the level of fluid reaches the or a said passage, the said fluid flows into the sleeve above the pumping sub to equalise fluid pressure on either side thereof and permit subsequent removal of the sleeve from the pumping sub.  
     
     
         12 . An apparatus according to    claim 11    wherein the sleeve includes a vent that in use lies above the said passage.  
     
     
         13 . An apparatus according to    claim 11    including one or more exterior projections that in use of the apparatus lie above the said passage and engage a drill pipe into which the sleeve is inserted, thereby retaining the sleeve at the top of the drill pipe.