Experimental study of the temporary plugging pattern of perforations by multi-particle size composites

Abstract

In the process of temporary plugging and diverting fracturing of horizontal wells, the seating of large-size temporary plugging balls on the perforation is unstable and the plugging efficiency of irregular perforations is low, so a smaller-size composite temporary plugging agent is needed to improve the temporary plugging efficiency. In this study, based on the actual situation of Changqing oilfield, three kinds of temporary plugging materials with small particle sizes were used to plug the perforation. A simulated perforation plugging device with different permeability was built by artificial cores, and the plugging law and pressure-bearing capacity of the composite temporary plugging materials inside the perforation were studied. The results show that the temporary plugging materials with particle sizes smaller than the diameter of the perforation can form a plug inside the perforation, and the plugging zone formed inside the perforation is discontinuous. The plugging zone has good pressure-bearing performance, and the indoor blocking pressure is more than 15 MPa. The orthogonal experiments showed that the importance of three kinds of temporary plugging agents in the composite temporary plugging materials were 3-4 mm particles, 0.15 mm powder, and 1-2 mm particles, and the optimal ratio is 3:3:2. This study provides a technical basis for the design of the temporary plugging and diverting fracturing.