Abstract: The main layer of the shale in Pingqiao block of Fuling shale gas field has a depth of 3 900-4 100 m, which is located in the strong compressive stress area and has large formation dip, so the effect of formation fracturing is limited. The optimization of deep fracturing technology was studied by combining experimental simulation with field test. The results show that optimizing deep fracturing technology mainly includes the following methods: (1)Optimizing the distance of stages between 45 m and 50 m; (2)Using directional three-cluster perfora-tion can avoid the problem of deep fracture extending along the bedding, but also can ensure that the fracture has a certain degree of complexity; (3)Rapidly increasing the construction displacement of pre-glue fluid and increasing the construction displacement step by step in the stage of drag-reducing water and sand-carrying, which is beneficial to increase the complexity of the fractures after forming a certain width of main fracture in the initial stage; (4)The single-stage construction scale should be controlled at 1 900-2 000 m³. Compared with the conventional fracturing process, the net pressure in fracture increased by 12.5%, the average sand-fluid ratio increased by 75.56%, and the average single-stage gas production increased by 114.90%. The optimized process has broad application prospects.

Key words: fracturing, deep shale, distance between stages, directional perforation, construction displacement, construction scale