Fracturing Parameters Optimization of Horizontal Wells in Shale Reservoirsduring "Well Fracturing-Soaking-Producing"

Regarding the absence of a systemic and complete method for optimizing the multi-stage fracturing parameters of horizontal wells in shale reservoirs during well fracturing-soaking-producing, a fracturing parameter optimization method was developed based on the dynamic inversion theory. First, a numerical model (EDFM-NM) for horizontal wells was established depending on the complex induced fracture networks formed in hydraulic fracturing of shale oil reservoirs, which takes into consideration the characteristics of the reservoirs as well as complex natural fractures. With the model, solution for the pressure of reservoirs with discrete natural fractures and numerical solution of bottom hole pressure of horizontal wells after multi-stage fracturing were obtained. Second, approaches for optimization of stage spacing, soaking time, and well spacing were proposed utilizing the dynamic analysis. Finally, the optimization method was applied to shale oil Well XC in Changqing Oilfield. Reasonable stage spacing, soaking time, and well spacing were found to be 100−125 m, 25−35 d, and 590−610 m, respectively. The research results can provide a theoretical basis for the optimization of fracturing parameters during “well fracturing–soaking–producing” of shale reservoirs in Changqing Oilfield.