SSAS is a powder sulphonated asphalt, which is different from the present national products with the same name and made from coal tar pitch, fuming sulphuric acid and sodium humate. Based on the factors of the chemical components, material structure, molecular weight,causes of geological formation and fined technology etc., the sulphonated asphalt specially selected was sulphonated to gasous sulphoric anhydride, then neutralized and dried to form DSSAS. During processing the technical parameters, such as material dehydrlysis, concentration adjustment, sulphonating temperature, ratio of feedstock, reaction degree, blending condition, heat transmission and so on, have been properly controlled, held quality testings to guaratee the product properties e. g. stabilizing hole wall, inhibiting the dispersion of cuttings, filtration control at high temperature and lubrication, anti-sticking and emusification as well.DSSAS is not a single-function additive, but a multi function, such as anti-sticking, lubrication, emulsification, filtration control, increasing mud redispersibility at high temperature etc.We reasonally adjust the adding volume to desired requirements. It is harmless to people or am mals. And there is also no pollution to environment. Through application of 3,000t to over 1,000 oil-gas wells in three oilfields, it had abtained obvious effects and good social and economical benefits. The specialists who assess it have thought that, the product had uniquely selected.material, scientific prescription, advanced gas-solid phase sulphonated technology and mid-fi nal control, and superior to the traditional products, It has not only held an lead in China, but also reached international level, and won the second-grade prize of science and technology of MGMR.