Method for Fracturing Coalbed Gas Reservoir Using Nitrogen Foam Fracturing Fluid

Abstract

The invention relates to a method for fracturing coalbed methane reservoirs by using nitrogen foam fracturing fluid, and fracturing coalbed methane wells, wherein the coalbed methane wells include: fracturing operation strings, well completion casings, packers, hydraulic Anchors and sliding sleeves; nitrogen foam fracturing equipment includes sand tanks, sand mixing trucks, liquid distribution tanks, liquid distribution pumps, liquid nitrogen trucks, liquid nitrogen pumps, foam fluid generators, fracturing pump trucks, and high-pressure tees; A method for fracturing coalbed methane reservoirs with foam fracturing fluid, comprising the following steps: S1, preparation before nitrogen foam fracturing operation, S2, pumping nitrogen foam fracturing fluid, S3, fracturing crack control, S4, fracturing construction Parameter monitoring and regulation, S5, fracturing fluid flowback, S6, post-fracturing evaluation. Compared with the prior art, the present invention can significantly reduce the leakage of fracturing fluid during the fracturing process of coalbed methane reservoirs, has little reservoir pollution, high construction safety, fast flowback speed of fracturing fluid, and short construction period; simple operation steps , the construction parameters are clear, and the operability is strong.

Description

technical field [0001] The invention belongs to the field of oil and gas resource development, and in particular relates to a method for fracturing coalbed gas reservoirs by using nitrogen foam fracturing fluid. Background technique [0002] As a clean energy source, coalbed methane is an important part of unconventional natural gas in my country. It is a self-generated and self-storage gas in coal seams, and its main component is methane. Coalbed methane exists in two states of adsorption and dissociation in coal seams. Due to the lack of free coalbed methane, the production of coalbed methane wells is generally low, which cannot reach the economic mass production index. Therefore, it is necessary to perform fracturing stimulation operations on coalbed methane reservoirs. At present, the main methods of fracturing and stimulating CBM wells include: water-based fracturing (active water, jelly fracturing fluid, clean fracturing fluid), oil-based fracturing and CO2 fracturing...

AI Technical Summary

Problems solved by technology

[0004] (2) In the jelly fracturing method, a large amount of jelly residue remains in the reservoir during the fracturing process, resulting in serious reservoir pollution

After the fracturing is completed, it is not easy to break the gel, which blocks the flowback channel of the reservoir water and significantly reduces the gas production capacity of the coalbed methane well

[0005] (3) Oil-based and clean fracturing fluid methods have high construction costs, low safety, and difficult control of gel breaking, resulting in their low application in coalbed methane well fracturing

[0006] (4) CO 2 The dry fracturing method requires high equipment and poor sanding capacity (CO 2 There is no way to add a large amount of sand in the sealed tank), and it is impossible to effectively control the size and shape of the fracture during the fracturing process

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