Sulfonated Asphalt, Modified Starch, Lubricant manufacturer / supplier in China, offering Water Based Drilling Mud Additive Filtrate Reducers Modified Starch for Oilfield, Oil Drilling Chemical Auxiliary Agent Modified Starch Oil Drilling Fluid, Oil Drilling Mud Additive Shale Stabilizer / Sodium Asphalt Sulfonated / Sulphonated Aspahlt and so on.