Low permeability gas reservoir turning repeated fracturing technological method

Abstract

The invention provides a low permeability gas reservoir turning repeated fracturing technological method. The specific technological method comprises the following steps of gas well initial fracturing failure or low-efficiency reason analyzing, reservoir stratum evaluating conducted before turning repeated fracturing, turning repeated fracturing well selection and stratum selection decision making, rock mechanical parameter and ground stress testing, turning repeated fracturing ground stress field changing simulating, fracture geometrical parameter and flow conductivity optimizing, turning repeated fracturing technology optimizing, fracturing liquid and turning agent studying, repeated fracturing constructing and evaluating conducted after repeated fracturing. The well selection and stratum selection decision making and residual gas detecting serve as verification systems of each other, fracturing design and fracture detecting serve as verification systems of each other, and a novel fracture turning agent is used in the low permeability gas reservoir turning repeated fracturing technological method. The integrated design of the low permeability gas reservoir turning repeated fracturing is achieved, and the low permeability gas reservoir turning repeated fracturing technological method has the advantages that the design links are macroscopically integrated, local innovation is achieved, linkage is close, mutual verification is achieved, the design is advanced, and the technological advantage is obvious.

Description

technical field [0001] The invention relates to a low-permeability gas reservoir diversion repeated fracturing process, which belongs to the field of petroleum fracturing. Background technique [0002] Most of the gas reservoirs in my country are low-permeability gas reservoirs. Such gas reservoirs generally have the characteristics of low porosity and low permeability. They have low natural productivity and poor conditions for stable production. Most wells have to undergo sand fracturing before being put into production. However, affected by various factors such as geology and engineering, some wells have low production after the initial fracturing, and even fail to reach the industrial gas flow. Even if the economic recovery value is reached, after long-term production activities, the fracture conductivity gradually decreases until it fails, which seriously affects the gas field. For the normal development of such wells, refracturing must be carried out in order to restore...

AI Technical Summary

Problems solved by technology

[0005] However, in the diversion fracturing of low-permeability and ultra-low-permeability gas wells, especially non-water-producing gas wells, this kind of plugging agent has the problem of difficulty in degradation, which affects the effect of diversion fracturing, and even leads to ineffective fracturing

In addition, another problem with the above kinds of diverting agents is that after the diverting agent is degraded, the temporary plugged part of the fracture is easy to close, resulting in a decrease in the fracture conductivity and the production of oil and gas wells

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