Study on a New Drilling Fluid Lubricant BH-MAL

A white-oil based lubricant, BH-MAL, is developed for use in drilling fluid to solve the problems faced with lubricants presently used. These problems include poor stability at elevated temperatures, fluorescence that interferes with logging interpretation, foaming, and poor lubricity of mud cake. BH-MAL is prepared with white oil, surfactant OP-7 and a newly developed lubricant additive in a mass ratio of 90︰3︰7. Pre-hydrated bentonite mud, when treated with 0.25% of BH-MAL, has its adhesive friction reduced by 75%, greatly reducing operation cost. BH-MAL can be used at up to 180 ℃, has a fluorescence level of 2, and does not cause drilling fluid to foam, satisfying the need for filed application. BH-MAL has some tolerable effect to the rheology of drilling fluid.