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Title: Hydraulic catworks system

Patent ·
OSTI ID:6344915

A hydraulic catworks system is described for use on a well drilling rig for making up and breaking out a drill string which includes a hydraulic makeup piston and cylinder assembly for actuating a makeup line connected to the makeup tongs, and a breakout piston and cylinder assembly connected to a breakout line for actuating the breakout tongs. A makeup hydraulic control valve controls hydraulic fluid to first and second lines connected to the makeup assembly with the first line connected for extending the makeup line and the second line connected for retracting the makeup line. A breakout hydraulic control valve controls fluid to third and fourth lines with the third line connected for extending the breakout line and the fourth line connected for retracting the breakout line. Manual air control means are provided for selectively actuating the makeup and breakout control valves. A variable pressure control is connected to the second line for controlling the makeup torque. Preferably, the makeup and breakout assemblies are vertically connected to the legs of the drilling rig and rollers are positioned horizontally with the makeup and breakout tongs and connected to the breakout and makeup lines. Preferably, a sheave is connected to the makeup assembly and the makeup line passes over the sheave with its free end fixedly secured. A re-generative system is provided on the makeup assembly for increasing the speed of the makeup line extension. Preferably the makeup and breakout cylinders are of the same cross-sectional area with the stroke of the breakout cylinder being less than the stroke of the makeup cylinder.

Assignee:
IFI; EDB-81-105570
Patent Number(s):
US 4253354
OSTI ID:
6344915
Resource Relation:
Patent File Date: Filed date 12 Sep 1979
Country of Publication:
United States
Language:
English