缝面位移控制压裂裂缝同步扩展数值模拟.

Segmented multi cluster fracturing is an important process for effective production of unconventional oil and gas reservoirs. The complexity of fracturing fractures is the basis for improving single well production and controlling reserves. The expansion of reservoir fractures is more complex affected by formation physical properties and fracturing process parameters. In order to explore the morphological characteristics and influencing factors of synchronous propagation of fracturing cluster fractures, a mathematical model of segmented fracturing plane slit displacement parameters controlling double cluster fracture propagation is established. Through the core mechanical experiment and numerical simulation of typical wells, the results show that: (1) the synchronous propagation of segmented fracturing cluster fractures is closely related to the well deviation angle. When the well deviation angle is reduced from 90° to 0°, the fracture propagation morphological characteristics change from symmetrical to asymmetric. At 90°, the cluster fractures deflect outward, and the directions of the maximum and minimum principal stresses turn at the fracture tip and stress shadow area, which is more conducive to the formation of complex fracture network; When it is less than 90°, the slit deflects to the inside. (2) The intensity of stress interference between clusters of staged fracturing is positively correlated with the fracturing displacement and negatively correlated with the distance between clusters. Fracturing displacement has an obvious effect on increasing the expansion distance of fracture length and width, which can effectively improve the controlled reserves range of a single well, but there is an upper limit on the expansion of fracture width; When the cluster spacing is 10 m, the displacement of each hole is not less than 0.12 m³/min to effectively form the stress interference between clusters; When the displacement is 0.18 m³/min and the distance between clusters is less than 20 m, the stress interference between slit is significant, and the directions of the maximum and minimum principal stresses turn, which is better to form a complex joint network. When the distance between clusters is greater than 20 m, it is not conducive to the formation of a complex joint network. (3) The microseismic fracture detection confirms that the numerical simulation results are consistent with the fracture propagation distance of the adjacent well microseismic detection. Staged fracturing can effectively improve the complexity of the fracture network of unconventional oil and gas reservoirs, and improve the production and control reserves of unconventional resource by increasing the well inclination, increasing the fracturing displacement and reducing the cluster spacing. [ABSTRACT FROM AUTHOR]