A close-cut fracturing method

Abstract

The invention relates to a close-cut fracturing method. The method includes: evaluation of shale parameters and optimization of fracture parameters and fracturing construction parameters; performing a first perforation operation; fracturing treatment; liquid rubber plug of the agent; replacement operation; carry out the second perforation operation; fracturing treatment, replacement operation; temporary plugging of the reconstructed perforation cluster; fracturing treatment for the unmodified perforation cluster; replacement operation; next Insert the bridge plug, repeat the above until all constructions are completed; drill the plug after pressing, flow back, test and produce. Through two perforation operations and temporary plugging in a single stage, the difficult operation of 5-8 clusters was transformed into a 3-stage fracturing operation, thereby reducing the conventional single-stage 3-6 clusters to a single-stage 1-2 cluster fracturing operation, increasing the single-cluster fluid intake, reducing the demand for displacement in fracturing construction, and increasing the construction pressure window; at the same time, the horizontal principal stress difference is reduced through stress shadowing, which increases the complexity of fractures and increases the depth of Shale gas well stimulation volume.

Description

technical field [0001] The invention relates to the field of fracturing, in particular to a multi-cluster fracturing technology for shale gas wells, and in particular, to a tight-cut fracturing method suitable for deep shale gas wells. Background technique [0002] my country is rich in deep shale gas resources with a depth of more than 3500 m, accounting for more than 85% of shale gas resources. Therefore, the successful development of deep shale gas resources is of great significance for my country to further tap potentials and increase reserves. Practice has proved that the close-cut fracturing process, that is, reducing the cluster spacing and increasing the number of fracturing clusters, is one of the important ways to achieve efficient development of deep shale gas. Taking North America as an example, from 2011 to 2017, the cluster spacing of Haynesville shale gas wells decreased from 15 to 24 m to 10 to 15 m; in the Eagle Ford shale oil and gas area, the average clust...

AI Technical Summary

Problems solved by technology

[0007] In order to solve the problems existing in the existing deep shale gas fracturing, the present invention proposes a new fracturing method, through which the perforating gun is perforated twice to realize 1 to 2 clusters of fluids in a single section, reducing the The displacement and construction pressure requirements increase the construction pressure window; at the same time, using the stress shadow effect generated in the multi-cluster crack expansion, the horizontal principal stress difference is reduced, and the difficulty of crack network formation is reduced, so as to realize the narrow construction pressure window. Intensive cutting of sweet spot areas under certain conditions, thereby improving the reservoir stimulation effect of deep shale gas wells

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