RESEARCH OF EXPANSION GRAIN CHEMICAL FOR WATER SHUTOFF AND PROFILE CONTROL

The underground cross-linked degree and the selective injectivity of the gel are the important factors influencing the effects of water shutoff and profile control. To deal with them better, a new kind of expansion grain chemical has been developed. It is a surface pre-crossliked polymer, with the advantages of controllable expansion and grain size, nearly same specific gravity as water, good stability and selectivity. With the help of it, the problems such as non-crosslinking of conventional water shutoff and profile control chemical in the formation have been solved. Meanwhile, the reasonable selection of grain size and injection pressure has made the chemical plug the surface of the low permeability formation and enter into the high permeability flushed formation. Thus,the objective for water shutoff and profile control chemical selectively entering into the large pore channel has been attained.