The operations in rotary drilling comprises of 3 systems that work simultaneously in boring a hole; a hoisting system that raises and lowers the drill string in and out of the hole, a rotating system which rotates the drill bit and a circulating system that moves fluid around from the drill stem, out of the drill bit and up again to the hole at the surface (Dyke & Baker, 1998). Choosing a fluid type depends on 3 important factors; Cost, Technical performance, Environmental impact. The cost of products is very important, and should be considered on a cost-performance basis. Technical performance of the drilling mud is the most important factor (Hawker, 2001) (Devereux, 1999). The study focuses on investigating the effect of bone dust on the different mud samples and studying how they behave when they are subjected to different conditions. To do this, a number of experiments will be carried out on different mud samples with varying amount of bone dust at certain temperatures and ageing times to help the mud samples perform maximally. Amongst the tests to be carried out are filtration or water loss test, swell tests, lubricity, rheological test of the different mud samples, ageing and temperature tests.

http://www.ritchiewiki.com/wiki/index.php/Rotary_Drilling
https://link.springer.com/article/10.1007%2Fs13202-013-0059-9