A shale gas well co 2 and slick water hybrid fracturing process

Abstract

The invention discloses a shale gas well CO2 and slickwater mixing fracturing technology, and relates to the technical field of shale gas exploiting, in particular to the mixing fracturing technology by adopting CO2 and slickwater. In the construction process, a fracturing truck, a fracturing blender truck, a CO2 tank truck, a CO2 pump truck, a measuring truck, a fracturing manifold truck, an acid tank, propping agents and a liquid storage pot group need to be prepared, the fracturing manifold truck is provided with a low-pressure manifold and a high-pressure manifold, and the measuring truck is provided with a monitoring instrument, and the technology is characterized by comprising seven steps of doing well site planning, pressure testing, acid liquid processing, CO2 fracturing construction, slickwater fracturing construction, well closing after fracturing, and flow opening and flowback after fracturing. The shale gas well CO2 and slickwater mixing fracturing technology has the advantage that the shale gas exploiting method which is low in cost, low in relative construction difficulty, small in damage to a shale gas reservoir stratum and efficient is achieved.

Description

technical field [0001] The invention relates to the technical field of shale gas exploitation, in particular to a 2 and slick water mixed fracturing process. Background technique [0002] Shale gas refers to the natural gas that mainly exists in the interlayers of dark mudstone, high-carbon mudstone, shale and silty rock in an adsorbed or free state. Shale gas is different from conventional natural gas reservoirs. It is not only the source rock for natural gas generation, but also the reservoir and cap rock for accumulating and preserving natural gas. Due to its low porosity and low permeability, all shale gas wells usually need to be fractured. Transformation can be mined. [0003] At present, the fracturing method used in shale gas wells is mainly slick water large-scale fracturing. The slick water fracturing fluid system is mainly composed of chemical additives such as clean water, drag reducer, drainage aid, clay stabilizer, and fungicide. The water consumption of cra...

AI Technical Summary

Problems solved by technology

The slick water fracturing process has adverse effects in the following two aspects. First, the high clay content of shale reservoirs predestined potential damage to formations caused by large fluid volumes. A large amount of water entering the reservoirs will cause clay minerals to expand and disperse to migrate. This leads to a decrease in permeability and blockage of pore channels, which affects the final stimulation effect; secondly, a large amount of liquid also consumes a large amount of water resources, which also seriously affects the flowback speed and flowback efficiency of fracturing fluid, which seriously affects fracturing stimulation. Effect

[0004] Chinese invention (CN102852508A) proposes a liquid CO 2 Although the fracturing process solves the problems of high damage to shale gas reservoirs, low flowback speed and flowback efficiency of the slick water fracturing process, the use of liquid CO 2 During the fracturing process, it is necessary to be equipped with more sophisticated instruments, such as a closed sand mixing vehicle, the corresponding cost increases, and the construction process is relatively difficult, so it is not suitable for large-scale promotion

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