The product is derivant of humic acid. Put lignite or weathered coal at the proper temperature and under sulfonate technical and special reaction, get this product. The product can improve the filter cake, decrease the fluid loss, resist high temperature, and is suit for various water-based drilling fluids, especially suit for composing "Three sulfonate" drilling fluids and have better effect. It can improve the high temperature stability of the drilling fluid, and is compatible with common used drilling additives. any more detail, please see