A Test Device System for Cracking Mud Shale under Hydraulic Fracturing

The exploitation of shale gas has always been a major problem, and the solution to this problem must start with the study of its nature. A kind of simulation device and monitoring method of mud shale cracking was designed and assembled by ourselves. First of all, made with two layers of the general principle and four layers of 60 ° prefabricated crack two groups of similar material sample of the shale, then in turn for each block of multistage hydraulic fracturing test, and the use of strain gauge for strain monitoring. Results show that under the condition of no native prefabricated crack, hydraulic direction tend to toward weak bedding plane direction of crack extension until she reached the weak bedding surface, and then the main cracks along the weak bedding surface directly, at the same time there are prefabricated crack in native and weak stratification plane, in stage and the area between the prefabricated crack priority area map cracking formation, the results for the exploitation of shale gas has important guiding significance.