A low-cost drilling rig is being developed, based on the Asian Sludging technique; a hand operated percussion drill where cuttings are removed by being drawn up the drill string under suction. This thesis investigates the drilling rig proto-type by considering aspects of the drilling operation including stroke length, stroke type and fluid viscosity. The relationship between these variables with both fluid discharge and drill penetration are discussed. The effect of using a funnelled cutting shoe on the end of the drill string is also studied. The thesis shows that the penetration of the drilling rig in soft material directly corresponds with the fluid discharge that it receives. A high solid load in the drilling fluid and a high pumping head are both identified as prime causes for a loss in potential fluid discharge. The cutting shoe greatly enhances the performance of the drilling rig.
Wardle, C. Investigation into the effective use of a low-cost water well drilling rig. (1999) 54 pp. [MSc thesis, Cranfield University at Silsoe]