Device for testing true triaxial hydraulic fracturing strain characteristic of rock

Abstract

The invention discloses a device for testing the true triaxial hydraulic fracturing strain characteristic of a rock. The device includes a loading frame, an axial lifting mechanism, an axial load sensor, a hydraulic fracturing plug, a strain gauge, a static strain gauge, a true triaxial clamper, an X-direction stress control system, a Y-direction stress control system and a hydraulic fracturing control system, the axial lifting mechanism is arranged at the bottom of the loading frame, and the axial load sensor is arranged at the upper part of the loading frame; the X-direction stress control system and the Y-direction stress control system are respectively connected to the left side and the right side of the cylindrical shell of the clamper through stress joints; and the strain gauge is vertically arranged in a cavity and contacts with a rock core to be tested, and the static strain gauge is respectively electrically connected with the strain gauge and the axial load sensor. The devicerealizes the development of indoor hydraulic fracturing experiments and test of the stress and strain characteristics of the rock during the experiments by using true triaxial stress loading, and hasthe advantages of beautiful and compact overall structure, complete functions and easiness in operation.

Description

Technical field [0001] The invention relates to the technical field of petroleum geology, and specifically to a rock true triaxial hydraulic fracturing strain characteristic testing device. Background technique [0002] Since natural rocks are generally subjected to three-dimensional stress in the underground environment, the laboratory study of the stress-strain characteristics of the rock during hydraulic fracturing under the three-dimensional stress state can better reflect the actual situation of the natural rock mass. [0003] Limited by true triaxial stress loading, the existing equipment is generally limited to hydraulic fracturing fluid pressure and flow monitoring, which can locate and record the occurrence and expansion of fractures in the fracturing simulation test; [0004] For example, the publication number is 105352811A, the publication date of the Chinese patent document on February 24, 2016 discloses a small hydraulic fracturing triaxial evaluation test pressurizatio...

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Problems solved by technology

[0005] However, under the joint action of hydraulic fracturing and triaxial stress, the research on the real-time recording and quantitative description of the stress-strain characteristics of the core with the change of pressure and flow rate or the change of fracture generation and expansion process is still relatively rare.

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