Pressure-control fracturing method for improving fracture complexity of deep shale gas well

Abstract

The invention discloses a pressure-control fracturing method for improving fracture complexity of a deep shale gas well. The pressure-control fracturing method comprises the following steps of (1) evaluating key shale parameters and optimizing fracturing construction parameters; (2) carrying out perforation operation; (3) carrying out acid treatment; (4) making a main fracture by adopting a high-viscosity glue solution; (5) injecting high-viscosity slickwater carrying a 80-120-mesh propping agent; (6) injecting high-viscosity slickwater carrying a 40-70-mesh propping agent; (7) injecting a high-viscosity glue solution; (8) injecting an acidic slickwater system; (9) repeating the steps (6)-(8) twice or more; (10) injecting a high-viscosity glue solution carrying a 40-70-mesh propping agent;(11) carrying out displacement operation by adopting displacement liquid, and then tripping in a bridge plug; and (12) repeating the steps (2)-(11) until construction completion of all sections, andfinally, carrying out plug drilling, flowback, testing and production solving after fracturing. According to the pressure-control fracturing method, the high-viscosity liquid is replaced by the acidicslickwater to be matched with a variable-displacement fracturing process, so that the efficient transformation of deep shale gas is realized.

Description

technical field [0001] The present invention relates to the field of oil field development, in particular to the segmented multi-cluster fracturing technology for shale gas wells, in particular to a hydraulic fracturing method suitable for deep shale gas wells, and in particular to a deep shale gas well with complex fracture enlargement A unique controlled pressure fracturing method. Background technique [0002] Blocks such as Jiaoshiba, Weiyuan, and Dingshan are rich in deep shale gas resources and have a large gas-bearing area. According to statistics, the deep shale gas resources at a depth of 3,500 m account for more than 65% of the total resources. Among them, the 3,500 m deep shale gas in the Sichuan Basin With deep shale gas resources as high as 4612×10 8 m 3 Therefore, the successful development of deep shale gas resources is of great significance for my country to further tap the potential and increase reserves. [0003] Development practice shows that deep shal...

AI Technical Summary

Problems solved by technology

[0010] To solve the problems of narrow operating pressure window and difficulty in increasing the complexity of fractures in the fracturing of existing deep shale gas wells, the present invention proposes a deep shale gas well The pressure-controlled fracturing method is to increase the net pressure in the fracture by adjusting the discharge of glue and spacer fluid, thereby opening natural fractures, and controlling the rising speed of the surface pump pressure under a narrow construction pressure window; subsequent pumping of acidic slippery water, Through viscosity fingering and acid dissolution, the natural fractures are further extended and communicated to increase the complexity of the fractures; at the same time, the small particle size proppant carried is used to further enhance the long-term flow conductivity of the reconstructed volume

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