A method for evaluating crack diversion performance

Abstract

The invention discloses a method for evaluating fracture diversion performance, and belongs to the technical field of volume fracturing. The evaluation method of fracture diversion performance is obtained by obtaining a core sample with a wellbore, fixing it in a simulated crack initiation device with a triaxial stress, and performing a fracturing test by injecting a preset displacement of fracturing fluid, The steering process of the simulated on-site fractures is realized. At the same time, by simulating the fracturing test under the on-site conditions, the waveform diagram of the pressure changing with time during the fracturing process is obtained, and the pressure value of the peak in the waveform diagram and its subsequent adjacent trough The pressure value of the pressure value is recorded as a set of pressure data, and multiple sets of pressure data are obtained. The pressure value of the peak in each set of pressure data is subtracted from the pressure value of the subsequent adjacent trough to obtain multiple sets of pressure differences. The pressure difference of multiple groups is summed and divided by the number of groups to obtain the diverting pressure difference of the core sample, and determine the fracture diverting performance of the core sample, which can play a certain guiding role for on-site fracturing construction.

Description

technical field [0001] The invention belongs to the technical field of volume fracturing, in particular to an evaluation method for fracture diversion performance. Background technique [0002] With the commercial development of the Sichuan Changning-Weiyuan National Shale Gas Demonstration Zone and the Chongqing Fuling National Shale Gas Demonstration Zone, volume fracturing technology has increasingly become a hot spot in reservoir stimulation technology. In order to achieve volume fracturing, temporary plugging and diversion technology is generally used to add temporary plugging agent in real time during the fracturing process to temporarily plug old or sanded fractures, and divert the fluid through changes in fracture pressure and fracture extension pressure, thereby creating Make a new seam. Fracture diversion performance directly affects the effect of volume fracturing, so the research on fracture diversion performance is very important. [0003] The existing evaluat...

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Problems solved by technology

[0005] The core specimens used in the existing evaluation methods are small in size and cannot ensure that the core is under the condition of formation stress, so that the turning process of the fracturing site cannot be truly simulated, and it is easy to cause the test results to differ from the fracture turning during the fracturing operation. Inconsistency, and thus cannot effectively guide the volume pressure operation in the actual production process

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