Experimental Study to Quantify Fracture Propagation in Hydraulic Fracturing Treatment

Hydraulic fracturing plays an important role in the commercial development of unconventional oil and gas, which is directly related to the production of oil and gas wells. An accurate evaluation is critical for hydraulic fracturing, but it is urgent to propose a quantitative assessment of hydraulic fracturing fracture propagation for realizing hydraulic fracturing fracture propagation and multiposition permeability measurement under an in situ stress environment. Herein, a true triaxial stress loading and permeability testing device was designed and fabricated, and a permeability evaluation model was established under various states, which can realize the accurate measurement of multiple faces and the total permeability of tight specimens before and after hydraulic fracturing. It can directly measure permeability under the conditions of the true triaxial fracture propagation experiment. The comparative experimental result shows that the new technique can quantitatively evaluate the fracture propagation experiment of true triaxial hydraulic fracturing. The overall permeability and the directional permeability of the five faces were obtained, and the fracture propagation was evaluated by comparing the change in permeability. The test permeability error rate is within ±10%. Furthermore, a more refined evaluation of hydraulic fracturing fracture propagation can be carried out based on the fracture observation and AE event results. The research results provide a new strategy for a more quantitative and refined evaluation of fracture propagation and help to optimize the parameters of hydraulic fracturing.