Volume transformation process of low permeability reservoir

Abstract

The invention discloses a volume transformation process of a low permeability reservoir, and the volume transformation process sequentially comprises the following steps of (1) selecting a coal bed, shale, tight sand or other low-permeability reservoir; and (2) adopting a pitching current-limiting hydraulic fracturing way after perforating a plumb shaft; adopting a segmental multi-cluster perforation hydraulic fracturing way after perforating a horizontal well; and varying displacement, propping agent, fracturing fluid and sand ratio in the pumping process in both fracturing ways. Due to adopting the measures for varying the displacement, the sand ratio, the propping agent and the fracturing fluid in the hydraulic fracturing process, pitching current limitation can be adopted when the plumb shaft is fractured or the segmental multi-cluster perforation fracturing process is adopted for the horizontal well, and a netted crack system is formed in the reservoir. Due to adopting the volume transformation process, the volume transformation effect is realized, the weakness of the traditional hydraulic fracturing process that a single crank cannot conform to the commercial production capacity or the later yield is reduced too fast can be avoided, and technical support can be provided for the oil-gas resource development of the low-permeability reservoir.

Description

technical field [0001] The invention belongs to the technical field of oil and gas exploitation and production, and in particular relates to a volume reconstruction process of low-permeability reservoirs. Background technique [0002] Low-permeability reservoirs such as coal seams, shale and tight sandstone contain abundant unconventional oil and gas resources, and reservoir stimulation technology is the key to realizing commercial production. However, in traditional hydraulic fracturing, when the net pressure of fracture extension is greater than the sum of the difference between the two horizontal principal stresses and the tensile strength of the rock, bifurcated fractures are likely to occur, and multiple bifurcated fractures will form a "fracture network" system. The main fracture is the backbone of the "fracture network" system, and the bifurcated fractures may return to the original fracture orientation after extending a certain distance from the main fracture, and fi...

AI Technical Summary

Problems solved by technology

However, in traditional hydraulic fracturing, when the net pressure of fracture extension is greater than the sum of the difference between the two horizontal principal stresses and the tensile strength of the rock, bifurcated fractures are likely to occur, and multiple bifurcated fractures will form a "fracture network" system. The main fracture is the backbone of the "fracture network" system, and the bifurcated fractures may return to the original fracture orientation after extending a certain distance from the main fracture, and finally form a single-directional fracture with the main fracture as the backbone, and store The formation has not been reformed, and the permeability is still poor, which is not enough to provide effective vertical permeability, resulting in low fracturing production or rapid production decline after fracturing.