Fracturing method of coal bed gas in smashed pea coal

Abstract

The invention provides a fracturing method of coal bed gas in smashed pea coal. Perforation parameters are optimized, and a liquid inlet channel is established in a stable coal seam section; in the whole fracturing process, the using proportion of pre-liquid volume is increased, and the pre-liquid volume is increased to 45-55% of total fracturing fluid; firstly, pure fracturing fluid accounting for 20-25% of the total fracturing fluid is pumped; then prepad fluid is pumped and a sand slug is added; sand-carrying fluid and the added sand slug support fractures and prevent sand blocking; and at last, displacing liquid is pumped. According to the fracturing method of the coal bed gas in the smashed pea coal, fracturing modification of the coal bed gas in the smashed pea coal can be effectively guided through the methods of optimizing the perforation parameters, optimizing the pumping procedure and the like.

Description

technical field [0001] The invention relates to the technical field of fracturing engineering for coalbed methane exploration and development, in particular to a coalbed gas fracturing method for finely divided coal. Background technique [0002] 1. Fracturing is an important measure for increasing the production of coalbed methane reservoirs. For the structural fragmentary coal whose original structure is damaged by stress, it can be effectively developed only through targeted fracturing. [0003] 2. The bedding rationality of the coal body structure of the crushed coal has been severely damaged, and the structure, structure, composition, and endogenous fractures of the coal seam have all changed. difficulty. [0004] 3. The existing method of reforming fine-grained coal mainly adopts conventional sandstone gas reservoir fracturing technology, that is, after the coal seam section is perforated, high-pressure liquid and proppant are pumped into the coal seam to obtain the e...

AI Technical Summary

Problems solved by technology

[0003] 2. The bedding rationality of the coal body structure of the crushed coal has been severely damaged, the structure, structure, composition, and endogenous fractures of the coal seam have all changed, the fractures in the seam are interlaced, the coal seam is loose as a whole, and there is a large amount of coal powder. difficulty

[0005] 4. In actual construction cases, conventional hydraulic fracturing methods failed to achieve good transformation results in the transformation of crushed coal

The main manifestations are: high fracturing construction pressure, wasting power of fracturing equipment; loose coal seams, severe liquid filtration and low efficiency; limited extension range of fractures; risk of sand plugging during construction; fractures are easy to close after fracturing, etc.