A pumping method for stepped displacement fracturing based on combined perforation

Abstract

The invention discloses a stepped displacement fracturing pump casting method based on combined type perforation. The stepped displacement fracturing pump casting method comprises the steps that (1) after perforation, quick water fracturing liquid is subjected to pump casting in a stepped displacement mode; (2) guar gum fracturing liquid containing a supporting agent is subjected to pump casting;(3) clear water is subjected to pump casting for replacement; (4) the supporting agent ratio is increased, and guar gum fracturing liquid containing the supporting agent is subjected to pump casting;(5) then clear water is subjected to pump casting again, and thus sand-containing liquid and the clear water are alternatively subjected to pump casting till the ratio of the supporting agent reaches20%; and (6) finally, a large amount of clear water is subjected to pump casting till the supporting agent conducts complete replacement in cracks. According to the stepped displacement fracturing pump casting method based on combined type perforation, combined-type-structural-perforation-containing shafts are further included, the situation that complex crack networks are formed in unconventionaloil-gas reservoirs with the large burial depths is facilitated, the scale of the hydraulic cracks is effectively increased, and thus the purpose that the permeability is artificially increased is achieved.

Description

technical field [0001] The invention relates to the technical field of unconventional oil and gas reservoir development, in particular to a combined perforation-based step displacement fracturing pump injection method. Background technique [0002] With the continuous reduction of conventional natural gas resources and the increasing difficulty of development, unconventional natural gas represented by shale gas and coalbed methane is affecting the world's energy structure. my country has abundant reserves of unconventional oil and gas resources and great potential for development. At present, breakthroughs have been made in the exploration and development of unconventional oil and gas resources. need to be resolved. [0003] Theoretical and practical research at home and abroad shows that segmented and clustered volume fracturing technology has become one of the main means of developing unconventional oil and gas reservoirs, and forming complex fracture networks in reservoir...

AI Technical Summary

Problems solved by technology

[0009] At present, research on fracturing of unconventional oil and gas reservoirs seldom involves relatively complex deep unconventional oil and gas reservoirs. As the development depth continues to increase, the structural in-situ stress becomes more and more complex, especially for those with strong heterogeneity and fractures. For well-developed shale reservoirs, due to the complexity and extension distance of fractures, it is often difficult to guarantee, thus reducing the recovery rate

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