A method for optimal design of perforation cluster position in staged multi-cluster fracturing of horizontal well

Abstract

The invention relates to an optimized design method for the positions of horizontal well segmented multi-cluster fracturing perforation clusters. The optimized design method comprises the steps that first, the positions of the perforation clusters of a first fracturing segment are determined according to borehole characteristics and development requirements; second, induced stress generated at a crack of the last perforation cluster of the first fracturing segment is calculated; third to sixth, the position of the first perforation cluster of an N fracturing segment is initially selected; seventh to tenth, the position of the next perforation cluster is initially selected, till the transverse transformation ranges of a perforation cluster crack and a previous perforation cluster crack are connected end to end; eleventh, the seventh step to the tenth step are repeated, till the requirement of the N fracturing segment number design is met; twelfth, the effective net pressure and induced stress of a crack at the last perforation cluster of the N fracturing segment relative to a stratum close to an (N+1) fracturing segment are calculated; and thirteenth, N is equal to N+1, the third step to the twelfth step are repeated, till the requirement of the transformation length of the horizontal segment of a well is met. The optimized design method better conforms to the actual working condition of segmented multi-cluster fracturing.

Description

technical field [0001] The invention relates to a horizontal well staged multi-cluster fracturing reservoir transformation technology, in particular to a horizontal well staged multi-cluster fracturing perforation cluster position optimization design method. Background technique [0002] Horizontal well staged multi-cluster fracturing technology is an effective means to develop unconventional low-permeability reservoirs. This technology can not only realize the communication between artificial fractures and natural fractures, but also use induced stress to promote stress diversion to generate diverted branch fractures. A complex fracture network is formed in the formation, which makes the seepage distance of oil and gas in the matrix in any direction "shortest" to the fractures, which greatly improves the overall permeability of the reservoir and the productivity and ultimate recovery of oil and gas wells. [0003] The formation of complex fracture networks in unconventional...

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Problems solved by technology

At present, no one has proposed an optimal design method for perforation clusters that meets the multi-cluster fracturing conditions of horizontal wells and aims at the end-to-end connection of the fracturing areas in the horizontal well section.

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