A foam-gas composite staged fracturing method

Abstract

The invention relates to a foam-gas composite stage fracturing method, which belongs to the technical field of hydraulic fracturing; it includes the following steps: 1) well drilling treatment; 2) liquid injection treatment: a gas storage tank truck injects liquid N through a booster pump. 2 Or air is injected into the wellbore through the annulus; 3) Perforation treatment: Coiled tubing transports and sprays water-based sand-containing perforating fluid; 4) Foam fracturing treatment: The injection fluid is replaced with water + foaming agent + foam stabilizer, Air and gas turbulently mixed into foam fracturing fluid; 5) Propping treatment: adding proppant to support the fracturing fracture; 6) Staged fracturing treatment: dragging continuous tubes sequentially or alternately to complete fracturing in all stages; 7) Gas Fracturing treatment: injecting liquid N into the wellbore 2 Or air; 8) Flowback of soaked wells: the foam fracturing fluid of the present invention is mixed in the downhole and fracturing in stages to avoid the high-pipe flow friction in the continuous tube, and use its high viscosity to plug the fractured fractures and then Injecting gas realizes unblocking of fractures, which solves the problems of poor fracturing effect and low work efficiency.

Description

technical field [0001] The invention belongs to the technical field of hydraulic fracturing, and in particular relates to a foam-gas composite staged fracturing formation method. Background technique [0002] my country is rich in unconventional oil and gas resources, but its low permeability requires reservoir stimulation methods such as fracturing to realize industrial exploitation. Gel, slick water, foam fracturing fluid, supercritical carbon dioxide (SCCO 2 ) and other fracturing fluid systems have been used in oil and gas reservoir fracturing operations. Among them, high-viscosity fracturing fluid such as gel has strong sand-carrying ability and is easy to form long, straight and wide fractures, but it is easy to cause damage to the reservoir permeability; slick water has low viscosity and is easy to form complex fractures, but the water consumption is large and the sand-carrying ability Weak; Patents CN 108165249A, CN 109111910A, CN 102766450B etc. published CO 2 , ...

AI Technical Summary

Problems solved by technology

[0004] The present invention overcomes the deficiencies of the prior art, and proposes a foam-gas composite segmental fracturing formation method, which solves the problem of poor fracturing effect caused by the large flow friction resistance of foam fracturing fluid coiled pipes existing in the current foam fracturing formation process. The problem of better and lower work efficiency, and the method of using the high viscosity of foam fracturing fluid to plug the fractured fractures and then inject gas to realize the unplugging of fractures

Images