Fluid-saving pump down tool

摘要

A fluid saver tool for deploying in a wireline string comprises a main shaft having a concentric seat attached to a lower end of the main shaft and a variable-diameter piston assembly concentrically disposed on the main shaft and seated against the concentric seat. A concentric thrust bushing is installed on the main shaft in contact with an upper end of variable diameter piston opposite from the concentric seat. The tool enables the deployment operation to be accomplished with much less water, lower pump pressures and energy losses, and substantially less time required to complete the operation.

主权项

1. A fluid-saving pump down tool to transport a wireline tool string downward through a well casing, comprising:
a main shaft having a concentric seat fixed thereto toward a lower end of said main shaft; a hollow expandable cylinder forming a variable-diameter piston concentrically disposed on said main shaft and seated against said concentric seat; a bow spring assembly surrounding said variable-diameter piston and fixed to said main shaft located at one end of said bow spring assembly; and a sliding thrust bushing configured to slide along said main shaft outside said hollow expandable cylinder spring assembly; said hollow expandable cylinder formed of an elastomeric material and having a reduced wall thickness intermediate a defined length thereof, wherein said reduced wall thickness intermediate said defined length thereof flexes outward under fluid pressure from fluid pumped into a wellbore, and wherein said fluid pressure from said fluid pumped into said wellbore bears against said variable-diameter piston causing said wireline string tool to be conveyed through said well casing.