High-temperature heat shock method for promoting creation of microfracture on hydraulic fracture surface of tight gas well

Abstract

The invention discloses a high-temperature heat shock method for promoting creation of a microfracture on a hydraulic fracture surface of a tight gas well. The theory is that high-temperature gas is injected into a preferable hydrofracture tight gas well to perform high-temperature thermal treatment on the hydraulic fracture surface, thermal stress and a thermal supercharging effect are achieved by using the heterogeneity and the anisotropism of thermal expansion of rock forming minerals, thermal expansion of water vapor and the pyrolysis hydrocarbon generation effect at high temperature due to possible existence of organic matters in rocks, so that microfractures grow near the hydraulic fracture surface on reservoir rocks. The high-temperature gas is continuously and intermittently fed toextend and cut through the microfractures to form a microfracture network, thus increasing the microfracture density of a tight gas reservoir. By implementation of the method, on the basis of hydrofracturing transformation, the tight gas reservoir recovery efficiency is further improved.

Description

technical field [0001] The invention relates to the field of production stimulation and transformation of tight gas reservoirs, and relates to a method for increasing the density of a tight gas well fracture network, which belongs to the method of production stimulation and transformation in the process of tight gas exploration and development. Background technique [0002] Tight gas is playing an increasingly important role in my country's reserve growth and energy supply, and has extremely important mining value. Tight gas reservoirs are generally characterized by low porosity and low permeability. The key to effective development of tight gas and enhanced recovery is to form a fracture network in the reservoir to improve gas transmission capacity. Hydraulic fracturing is the key technology to realize the economical exploitation of tight gas. Although the current hydraulic fracturing technology can greatly increase the fracture network density of tight gas reservoirs, ther...

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Problems solved by technology

Hydraulic fracturing is the key technology to realize the economical exploitation of tight gas. Although the current hydraulic fracturing technology can greatly increase the fracture network density of tight gas reservoirs, there are still low flowback rates of fracturing fluid and room for further improvement of the fracture network density. Problems such as single fracture network scale and other problems have affected the effect of reservoir stimulation. The specific performance is as follows: (1) The flowback rate of fracturing fluid after hydraulic fracturing operation is low, and the retention of fracturing fluid causes damage to reservoir water phase traps

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