experimental study on membrane efficiency of shales through pore pressure transmission measurements

Membrane efficiency (me) in shale drilling particularly with water-based drilling fluids (wbdfs) has gained strong research attention due to the impact of oil-based drilling fluids on the environment and the legal challenges it presents. a suite of experiments has been conducted on selected bio-based plants containing surfactant property. these surfactants are used to formulate water-based drilling fluids and their performances tested through a pore pressure transmission test. results indicated that the type of membrane enhancer used in wbdfs affects the membrane efficiency of the shale-mud system. it also revealed that the saponin amount in the crude bio-surfactant used for the mud formulation correlates directly with the membrane efficiency and indirectly with the crude bio-surfactants critical micelle concentration (cmc). crude bio-surfactant particle size was found to have an impact on membrane efficiency at low permeabilities than at high permeabilities. depending on the bio-surfactant used membrane efficiencies were improved over several degree of percentages with the least improvement of 35%.