Optimum design method for staged fracturing perforation cluster parameters of horizontal well of shale reservoir

Abstract

The invention relates to an optimum design method for staged fracturing perforation cluster parameters of a horizontal well of a shale reservoir. The optimum design method includes the following steps of S1, selecting high-fracture-performance fracturing well sections; S2, building a mathematical model for hydrofracture fracture progressing, analyzing an induction stress field model for fracture extension, and analyzing a fracture diverting mechanism; S3, analyzing extending conditions of main fractures, and selecting cluster distances capable of allowing the main fractures to evenly extend forwards; S4, analyzing change conditions of stress fields around the main fractures, selecting the perforation cluster distances with the horizontal principal stress ratios smaller than 1.3, and determining the optimal perforation cluster distances in cooperation with the step S3; S5, further improving the complexity of the fractures through an alternate fracturing principle, and setting the perforation density of perforation clusters in the middle to range from 10 to 16 per m and the perforation density of perforation clusters in the two sides to be larger than 16 per m. By means of the optimum design method, the perforation cluster distances can be optimized, largest fracture transforming sizes can be obtained, the practical effect of reservoir transforming can be improved, and high construction cost and the poor fracturing effect which are caused by aimlessly setting the perforation cluster distances can be avoided.

Description

Technical field [0001] The invention relates to the technical field of oil and natural gas development. In particular, it relates to a shale reservoir horizontal well staged fracturing perforation cluster parameter optimization design method. Background technique [0002] Shale reservoirs are playing an increasingly important role in my country's reserves growth and energy security. Shale reservoirs have the characteristics of low permeability, high strength, and uneven distribution of reservoirs. The staged fracturing stimulation technology for horizontal wells is an important technology for developing such reservoirs and increasing single wells to control reserves and productivity. Staged fracturing of conventional horizontal wells adopts single-stage perforation and single-stage fracturing. From the perspective of reducing the interference between fractures, it is considered to increase the perforation spacing as much as possible to form multiple transverse fractures perpendi...

AI Technical Summary

Problems solved by technology

However, formation factors, multi-fractures and fracture spacing have an important impact on the fracturing results of horizontal wells, and the above factors have not been considered in the existing research at home and abroad.

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