String bypass
First Claim
1. A bypass apparatus for use in a testing string having a pump and a packer, said apparatus comprising:
- case means for positioning in said testing string between said pump and packer, said case means defining a transverse port therein in communication with a well annulus;
valve means disposed in said case means for moving between an open position and a closed position, said valve means having first passageway means thereon for providing communication between a central bore of said testing string and said port when said valve means is in said open position and for preventing said communication when said valve means is in said closed position; and
second passageway means for providing communication between said pump and said packer.
1 Assignment
0 Petitions
Accused Products
Abstract
A string bypass for bypassing fluid around a packer as a testing string is lowered into or raised out of a well bore. The string bypass includes an outer case with an inner mandrel positioned therein such that an annular cavity is defined therebetween. A reciprocating piston is positioned in the annular cavity. The case and mandrel both define transverse holes therethrough, and the piston includes a transverse passageway which provides intercommunication between the holes when the piston is in an open position. A spring biases the piston toward the open position. A pump is used to inflate the packer, and, as the pump pressure gradually increases, a differential between the pump pressure and well annulus pressure acts against an annular area on the piston and overcomes the spring force so that the piston is moved to a sealed, closed position in which communication between the holes is prevented. The piston also includes a substantially longitudinal passageway therethrough which provides continuous fluid communication between the pump above the string bypass and the packer below the string bypass.
29 Citations
20 Claims
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1. A bypass apparatus for use in a testing string having a pump and a packer, said apparatus comprising:
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case means for positioning in said testing string between said pump and packer, said case means defining a transverse port therein in communication with a well annulus; valve means disposed in said case means for moving between an open position and a closed position, said valve means having first passageway means thereon for providing communication between a central bore of said testing string and said port when said valve means is in said open position and for preventing said communication when said valve means is in said closed position; and second passageway means for providing communication between said pump and said packer. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A bypass apparatus for use in a well testing string between a packer inflation pump and an inflatable packer, said apparatus comprising:
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an elongated case defining a transverse hole therethrough; a mandrel having a transverse hole therethrough disposed in said case, said mandrel and case defining an annular cavity therebetween; a piston defining a passageway therethrough and reciprocably disposed in said annular cavity, said piston having an open position wherein said passageway provides communication between said hole in said mandrel and said hole in said case and further having a closed position, and said piston comprising; a first portion; and a second portion such that an annular shoulder extends between said first and second portions; and biasing means for biasing said piston toward said open position; wherein, said piston is movable from said open position toward said closed position when a differential pressure between said pump and a well annulus acting on a net annular area corresponding to an annular area of said shoulder is greater than a force exerted on said piston by said biasing means. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A downhole testing tool having a central flow passageway therethrough and comprising:
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a pump attached to an upper testing string portion; an inflatable packer disposed below said pump and positionable adjacent a well formation to be tested; a porting sub adjacent said formation and providing communication between said formation and said central flow passageway; and a string bypass disposed between said pump and packer, said string bypass comprising; first passageway means for providing fluid communication between said central flow passageway and a well annulus above said packer when said first passageway means is open, such that fluid in a well annulus below said packer will be bypassed around said packer as said tool is run into a well bore; valve means for opening said first passageway means for providing said fluid communication and closing said first passageway means in response to pumping pressure from said pump for preventing such bypassing of fluid; and second passageway means for providing communication between said pump and said packer. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification