A novel simulation approach for far-field temporary plugging fracturing in horizontal wells

Far-field temporary plugging fracturing can enhance fracture complexity and improve reservoir stimulation effectiveness, making it a powerful technique for the efficient development of unconventional oil and gas. Existing numerical methods face significant challenges in simulating the mechanical process of plugging the fracture tip and forcing the formation of new fractures. Numerical studies on far-field temporary plugging fracturing are rarely published, which constrains the application and development of this technique. This work developed a user subroutine to define field variable (USDFLD) to identify and control the rock properties at the fracture tip. It also established a numerical model for far-field temporary plugging fracturing based on the cohesive zone method (CZM). The model successfully achieved effective temporary plugging of propagating fractures, and its validity was verified through laboratory experiments. The results indicate that when the fracture tip encounters a temporary plugging body, fracture growth ceases and the pressure inside the fracture rises. The fracture width first increases until a new fracture forms, after which it gradually decreases. As the temporary plugging distance increases, the rate of internal pressure rise after contacting the temporary plugging body slows down. The farther the temporary plugging body is positioned, the greater the fracture width that can form during plugging. Implementing temporary plugging at a greater distance from the fracture tip is more beneficial for enhancing fracturing effectiveness. During Hydraulic fracture propagation, fractures may directly cross natural fractures. Implementing temporary plugging fracturing can activate structural weak planes that were not opened before plugging, thereby expanding the stimulated reservoir volume. On this basis, secondary temporary plugging further promotes the formation of new fracture paths and a more complex fracture network. The research provides a new tool for optimizing far-field temporary plugging fracturing design.