Performance evaluation of water soluble diverter agent and its temporary plugging effect in refracturing

Refracturing is one of the important ways to restore well productivity and improve the ultimate recovery. Currently, the most effective way of refracturing is reorientation refracturing using diverter agent. In this paper, a water soluble diverter agent was synthesized by environmentally friendly non-toxic materials, the diverter agent particle size can be customized according to the fracture width, and it has good water solubility and can be water soluble completely after 4 hours of fracturing operation. Cores flow experiments show that the water soluble diverter agent plugging efficiency can reach more than 99% under over 40 MPa pressure, it has little harm effect on cores permeability, which satisfies the requirements of refracturing. The water soluble diverter agent was applied in filed for one well, the refracturing pressure increased 5 MPa after adding the water soluble diverter agent, which showed a good temporary plugging effect. The daily production after refracturing increased 1.98t, water cut decreased 10%. The results show that this refracturing mode is able to restore well productivity and decrease water cut.