The influence of proppant breakage, embedding, and particle migration on fracture conductivity

Many studies that aim to reduce the damage to fracture conductivity caused by proppant breakage and embedding have been conducted. Few studies, however, have addressed the damage to conductivity caused by proppant particle migration, which is often neglected in practical design. In this paper, a series of experiments were performed to study the influence of proppant breakage, embedding, and particle migration on fracture diversion energy. The effect of particle migration on fracture conductivity was investigated by changing the injection velocity and closing pressure, and the particle morphology in the produced fluid obtained at different experimental stages was analyzed. The results show that proppant breakage, embedding, and particle migration are harmful to fracture conductivity. The damage of particle migration to conductivity is correlated with closing pressure and flow rate, and increased fluid injection velocity aggravates the blocking effect of particle migration. When flow rate increases from 5 to 20 ml/min, the damage rate of fracture conductivity reaches 47.16%. When closing pressure is less than 50 MPa, less conductivity is generated as a result of proppant embedding, with a damage rate of 12.7%. The large embedding of the proppant occurs at a closing pressure of 50 MPa, and the damage to conductivity increases from 12.7% to 85.6%. This paper can serve as a reference for the future study of fracture conductivity damage. © 2020 Elsevier B.V.