In order to alleviate this industry headache, researchers from the CSIRO, in conjunction with US firm Halliburton Energy Services' Baroid Drilling Fluids, have developed a low-cost, environmentally safe drilling fluid dubbed 'green muds'.

The green muds were created to perform as well as traditional oil and synthetic-based fluids when drilling difficult oil wells. "The green muds can also be more effective than oil and synthetic-based fluids which are normally used to maintain shale stability in the drilling of long-reach wells," CSIRO Petroleum said. "One clear advantage of this is that if operators can drill successfully and economically out to 10km or beyond, fewer platforms are needed to exploit the field."

The company added the key to drilling these long wells in shale is to maintain the precarious balance between drilling fluid pressure and rock stresses over extended periods of time.

The new green muds contain special polymers which coat the surface of the hole and minimise the fluid from the drilling mud from seeping in and destabilising the wellbore. A world patent has been filed for the formulations and trials for this drilling fluid system are now being conducted in the Gulf of Mexico and the North Sea.