Land rigs are generally either wheel-mounted portable types or a component system that must be moved by trucks and cranes. The drilling floor generally sits on top of a steel substructure that could be 30 fe.
[pdf] Several different kinds of top drives exist, and are usually classified based on the "Safe Working Load" (SWL) of the equipment and the size and type of motor used to rotate the drillpipe. For offshore and heavy duty use, a 1000 short ton unit would be used, whereas a smaller land rig may only require a 500 short ton device. Various sizes of hydraulic motors, or AC or DC electric motors, are available.
[pdf] Drilling derricks and Rig Masts consist of a steel framework with a square or rectangular cross-section. Their purpose is to support the hoisting equipment and rack the tubulars while tripping pipe. The numbe.
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