Multi-stage apparatus for installing tubular goods

Abstract

A pipe gripping assembly includes, among other components, a fluid conducting swivel, a fluid-powered linear actuator and a pipe gripping assembly. The linear actuator has a central rod mounted within a multi-stage, segmented barrel assembly. Each barrel segment acts as a piston, with control fluid forces being transmitted to the barrel assembly to selectively extend or retract the barrel assembly in order to engage or disengage the pipe gripping assembly. By aggregating such force, the total combined force generated by the barrel piston assemblies, the actuator assembly of the present invention can operate using pneumatic control fluid, and can operate at much lower control fluid pressures than other actuators.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention pertains to an apparatus for conveying pipe and other tubular goods within wellbores penetrating subterranean formations. More particularly, the present invention pertains to a fluid powered, multi-stage linear actuator and associated equipment that can be used in many different applications including, without limitation, in connection with casing running tools.[0003]2. Brief Description of the Prior Art[0004]Oil and gas operations frequently involve the use of pipe and / or other tubular goods manipulated from a surface drilling rig or other surface facility. Such tubular goods are usually inserted into a well in a number of separate sections of substantially equal length called “joints.” Such joints are typically screwed together or otherwise joined end-to-end at the rig floor of a drilling rig in order to form a substantially continuous “string” of pipe that reaches downward into the earth's crust...

AI Technical Summary

Benefits of technology

The present invention provides an RT that can operate using pneumatic power, eliminating the need for a hydraulic power source and reducing cost and logistical challenges associated with transporting the invention to and from a well site. The actuator of the invention can also be configured for operation using hydraulic control fluid, making it safer for use on small rigs and increasing lifting capacity while reducing the size of the actuator assembly.

Problems solved by technology

Although such top drive units have been used on drilling rigs for some time to make-up drill pipe connections and to efficiently drill wells, such top drive systems generally have not been used to make-up and run casing strings until relatively recently.

Conventional RT devices are often severely limited in terms of lifting capacity or rotating speed, or both.

Images