Wang Xingwen, Lin Yongmao, Miao Weijie. Volume fracturing technology of deep shale gas in southern Sichuan[J]. Petroleum Reservoir Evaluation and Development, 2021, (1): 102-108. DOI: 10.13809/j.cnki.cn32-1825/te.2021.01.014.
Volume fracturing technology of deep shale gas in southern Sichuan
low reservoir brittle(< 0.5)and the undeveloped natural fracture
the hydraulic fracture of Weirong deep shale gas face the problems of high fracturing construction pressure
narrower pressure window
low sensitive sand concentration
high fracturing difficulty. Largescale physical model experiments show that the morphology of Weirong shale fractures are composed of main fracture and branch fracture
within low fracture complexity and forming bedding seam more easily. On the basis of geology-engineering integration
the stratigraphic segmentation and clustering are optimized in combination with geological sweet spot. Through the study of the proppant transport
the placement mode and injection timing of the three-grade particle size proppant have been optimized
which increase the sand loading. The transverse complexity of fractures is improved by the combined temporary plugging steering fracturing technology. The net pressure and complexity of fractures are improved by the temporary plugging in the fractures and the optimization of construction discharge and liquid viscosity
thereby improving the fracturing volume and control reserves. The research results have been successfully applied in Weirong Gas Field. The sand loading has been increased to 1.95 t/m
the average open flow per well is 38.5×104 m3/d
and the single well EUR is 90×108 m3. All those shows a significantly improvement compared with the previous stage. Post-pressure evaluation shows that the fracturing effect is positively correlated with the sand adding strength. Therefore
how to improve the sand adding strength and control the strength of the liquid used in deep shale gas is the key to economic and effective fracturing.