Compact Rigs a Boost to Geothermal Drilling - Part 2
The use of compact drill rigs would help make geothermal resources more cost-competitive as a power-generating fuel. Last month, this article covered compact drill requirements relative to rig style, depth capabilities, coring capabilities and the rig's mast. We pick it up here, starting with primary power for the rig.
Approximately 1,000 horsepower (HP) should be adequate to run the drawworks, a THD and floor devices. The speed and torque flexibility of DC/SCR is a desirable advantage as is the smaller size of the motor. If, in addition, this prime mover were to be used to run four 400-HP mud pumps, at least 2,600 HP should be planned. If compressors/boosters are to be electric powered, then up to 4,000 HP might be needed. It seems logical to assume that an electrically powered THD would be vulnerable to serious damage or destruction if live steam were to escape the hole and come into contact with the THD. It should be noted that live steam also could seriously damage or ruin hoses used to run a hydraulic THD.