Abstract:

In order to solve the problem of quantitative design of fiber in fiber temporary plugging and diverting acid fracturing, a total stress field model considering the initial artificial fracture, adjacent well artificial fracture, pore pressure change, temperature change and in-situ stress is established. And then the prediction model of diverting radius is established by multivariate nonlinear regression. Meanwhile, methods such as the displacement discontinuity method（DDM） are used to solve the model, and combined with the fiber plugging mechanism, the design model of fiber dosage is established. The simulation results show that the induced stress value of the initial artificial fracture in the direction of minimum principal stress is larger, and the influence of artificial fracture of adjacent well or wells, pore pressure variation and temperature variation on stress diverting are small. The smaller the original in-situ stress difference, the longer the initial artificial fracture length, the smaller the well spacing, the larger the net pressure in the fracture, and the larger the diverting radius. When the in-situ stress difference is large, it is necessary to use the temporary plugging of fiber to increase the net pressure of the fractures, and the fiber dosage can be determined according to the design plate. Applying the above design method to a well in Xinjiang, the results were basically close to the on-site construction results, and the new fracture diverted successfully.

Key words: temporary plugging by fiber, diverting acid fracturing, stress field, diverting radius, fiber dosage