The principle of rotary screw air compression is really no different than reciprocating (piston) compression. Both are positive displacement machines that take in a fixed volume of air at atmospheric press.
[pdf] Use Our Compressor Maintenance Checklist – Download our free PDF to keep track of routine tasks. Track Your Data: Use our printable Rotary Screw Maintenance Schedule to record service dates, hours, and temperature readings.
[pdf] A bottom hole assembly (BHA) is a component of a drilling rig. It is the lowest part of the drill string, extending from the bit to the drill pipe. The assembly can consist of drill collars, subs such as stabilisers, reamers, shocks, hole-openers, and the bit sub and bit. The BHA design is based upon the requirements of having enough weight transfer to the bit (WOB) to be able to drill and achieve. VariationsRotary assemblies are commonly used where formations are predictable and the rig economics are an issue. In such an assembly the weight of the drill collars gives the BHA the tendency to sag or flex to the low s. .
A stabiliser is used within a column of drill collars. They help guide the bit in the hole. They play a major part in as it helps determine the well-bore path and angle. It is used to.
[pdf] 
