Stephen M Burrow

US Patent:

7117948, Oct 10, 2006

Filed:

Jun 28, 2004

Appl. No.:

10/878801

Inventors:

Mark Mazzella - Washington TX, US
Mike L. Smith - McAllen TX, US
Stephen M. Burrow - Willis TX, US
Brent S. Lim - Arlington TX, US

Assignee:

Varco I/P, Inc. - Fort Worth TX
Integrated Production Services LLC - Houston TX

International Classification:

E21B 10/086

US Classification:

166379, 166 774, 166383

Abstract:

A snubbing unit for running and retrieving a string of tubing into a well under pressure selectively operates in a stand alone mode and a rig assist mode. The unit has a lower frame for mounting during the stand alone mode on a snubber blowout preventer. Stationary weight supporting slips and snubbing slips are carried by the lower frame during the stand alone mode. The unit has four hydraulic cylinders with weight supporting slips and snubbing slips carried by a traveling base plate on the piston rods. A stationary base plate is mounted between the lower frame and the traveling base plate. A spacer tube is connected to and between the lower frame and the stationary base plate in the stand alone mode. In the rig assist mode, the lower frame along with the stationary weight supporting slips and the spacer tube are removed to enable a rig blowout preventer to connect to the stationary base plate.