NEW CASING TOOLS MAY ELIMINATE NEED FOR SUPER RIGS.

There is an alternative to bigger drawworks, higher capacity brakes, higher capacity masts, and bigger blocks. It is a hydraulic casing jack system. Instead of using the rig's capacity to hold the heavy string, an independent jacking system is used. Two load supporting columns are located between the sides of the substructure and sit on concrete foundations located in the wellhead cellar. Two 20-ft stroke, 500-ton capacity hydraulic cylinders are supported by them. Spider and elevator support beams straddle the cylinders and carry the casing load using conventional 1,000-ton casing elevator/spider combination units. A hydraulic power supply with accumulators and a load dissipating heat exchanger complete the major parts of the jacking system. The system is designed to be installed in the rig prior to running the casing and will not require any special rig modifications.