Reservoir transformation method and application of normal-pressure shale gas horizontal well

Abstract

The invention discloses a yield increasing method and application of a normal-pressure shale gas well. The yield increasing method comprises the steps that a shaft is subjected to acid treatment, and specifically, the shaft is pretreated through single-section acid liquor; prepad glue liquid joint making is conducted, glue liquid is injected to serve as fracturing fluid, the glue liquid displacement is increased in a stepped mode, and it is guaranteed that joints are effectively opened; pump injection of proppant-carrying hot slickwater is conducted for energy-enhancing joint expansion, the hot slickwater carrying a proppant is injected in a segmented mode, regular fluctuation of a construction pressure curve is controlled, and the purposes of improving reservoir energy, accelerating glue breaking and expanding the joints are achieved. According to the method, the shale energy value increased by fracturing can be quantified, so that the problems that the fracturing result cannot be quantified, the original reservoir temperature is reduced by the fracturing fluid, the reservoir energy of the normal-pressure shale gas reservoir is low, so that self-spraying production cannot be achieved, the natural gas in organic matter pores is slowly released, glue breaking is not thorough, the reservoir damage is easily caused and the like are solved. The method is high in operability, and the normal-temperature and normal-pressure shale gas fracturing effect is obviously improved and quantitatively evaluated.

Description

technical field [0001] The invention belongs to the technical field of production stimulation and transformation of shale gas reservoirs, and in particular relates to a production stimulation method and application of normal pressure shale gas wells. Background technique [0002] Atmospheric pressure shale gas refers to shale formations with a pressure coefficient of 0.8-1.2. Due to the tectonic uplift of formations during geological evolution, part of the originally generated hydrocarbons escapes, and the pressure and temperature of reservoirs are relatively low. Compared with the two, the difference is obvious, and the development of normal pressure shale gas is very difficult. How to produce atmospheric shale gas resources and realize its effective development has always been a major difficulty for researchers in shale gas exploration and development. [0003] At present, some active explorations have been carried out on normal-pressure shale gas horizontal wells, mainly...

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Problems solved by technology

[0003] At present, some active explorations have been carried out on normal-pressure shale gas horizontal wells, mainly using techniques such as staged perforation, continuous sand addition, and normal-temperature fracturing fluid construction, which have achieved certain results in southeast Chongqing, but shale gas still exists. Gas wells are difficult to produce spontaneously, and the production is low

[0004] From a technical point of view, the main problems of normal pressure shale gas fracturing are: normal pressure shale gas reservoirs usually have the characteristics of low pressure coefficient, low formation temperature, etc., and insufficient formation energy, which is manifested by the difficulty or inability of spontaneous flow production of horizontal wells , the flowback rate of fracturing fluid is low, and the electric submersible pump or jet pump can only be used to assist the drainage, which increases the production cost and makes it difficult to achieve the purpose of economical and effective development of shale gas; High sand-carrying ability and fluid loss control function, but if the gel is not completely broken after fracturing and still has a certain viscosity for a long time, it will significantly reduce the conductivity of the proppant-packed zone, resulting in different degrees of reservoir Injury, affecting production of shale gas wells

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