... the purification,modification,processing.developed with the bentonite for drilling mud,which quality meet European standards of OCMA and ... when used,can increase the lubrication of drilling,cleaning the debris during drilling,as well as for the rig-freeing ... agent.so which is widely used in complex geological formation drilling. Physical & Chemical IndexOCMAItemIndexViscosity 600 r/min≥30Yield value≤ ...