Study on the Optimization of Staged Fracturing for Horizontal Wells

In order to connect natural fracture with hydraulic fracture formed in staged fracturing for horizontal wells, forming a complex fracture network to improve the production of single well. Geometric model of hydraulic fracture induced stress field has been established, we studied the induced stress distribution of staged fracturing for horizontal well, compared the different effect of induced stress under the condition of different fracturing technology showed that: Induced stress along the minimum horizontal principal stress direction is the largest, with the increase of crack distance, induced stress decreased. Different fracturing technology can lead to different induced stress, the third crack fractured between two former cracks; induced stress of the third crack is obviously bigger than induced stress of crack by sequential fracturing. By comparing induced stress in the condition of fracturing three cracks, five cracks, seven cracks, found that induced stress increased with the increase of quantity of cracks. The larger induced stress made the branch crack shifted, enhancing connectivity among branch crack, main crack and natural fracture to improve channel structure for oil and gas flowing to the main crack, and finally achieve the purpose of improving productivity for oil and gas well. The study results had important guiding significance for efficient development of reservoir and optimization of parameters for horizontal wells.