Plugging equipment for ground fracturing plugging water-bearing stratum

Abstract

The invention discloses plugging equipment for a ground fracturing plugging water-bearing stratum. The plugging equipment comprises a fracturing plugging feed system, a stirring system and a discharge system, wherein the fracturing plugging feed system comprises two feed pipelines; the first feed pipeline comprises a first fracturing pumper which is connected with a first liquid tank; the second feed pipeline comprises a second fracturing pumper which is connected with a second liquid tank; the stirring system comprises a stirring cabin which is arranged at a well head; stirring blades which are connected with a power device are arranged in the stirring cabin; the discharge system comprises a bushing which is positioned below the stirring cabin and is communicated with the stirring cabin;the wall of the lower part of the bushing is provided with a hole; the lower part of the bushing is positioned in a well; and the first fracturing pumper and the second fracturing pumper are communicated with the stirring cabin through a first high-pressure hose and a second high-pressure hose respectively. The plugging equipment aims to solve the problem that the water-bearing stratum is possibly communicated with a coal seam in a fracturing process because the water-bearing stratum is closer to the coal seam; and in order to guarantee that the coal seam is not communicated with the water-bearing stratum of a surrounding rock during hydraulic fracturing, the plugging equipment for the ground fracturing plugging water-bearing stratum for fracturing and reconstructing of a coal reservoir is realized.

Description

technical field [0001] The invention relates to a plugging device for ground fracturing to plug an aquifer. Background technique [0002] At present, coalbed methane wells are mainly produced by desorption of coalbed methane through "drainage-depressurization". The characteristics of low permeability of coal reservoirs in my country determine that coal reservoirs need to be reconstructed before drainage. The heterogeneity of coal reservoirs, the complexity of coal-rock fracture systems, the mechanical properties of coal-rock rocks and the mechanical properties of surrounding rocks The differences in the fractures lead to the complexity of fracture extension and expansion during reservoir stimulation. Hydraulic fracturing technology has become the main fracturing fluid for coal reservoir reconstruction because of its wide supply, low price and good fracturing effect. However, the viscosity of active water is low. Therefore, in order to increase the fracturing effect, increas...

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Problems solved by technology

However, the viscosity of active water is low. Therefore, in order to increase the fracturing effect, increase the length and width of fractures, and the effective support fracture height and fracture length, the proppant particles are getting larger and the fracturing displacement is increasing. The amount of fracturing is also increasing. Under the same ground stress, coal and rock strength and other conditions, the construction pressure caused by large-scale fracturing is also increasing, and the possibility of breaking through the roof and floor of the coal seam is increasing.

When there is an aquifer within a certain distance from the top and bottom of the coal seam, it is easy to communicate with the aquifer. When the coal seam communicates with the aquifer, the water in the aquifer will flow continuously through the coal seam to the wellbore during drainage, which not only increases the difficulty of downflow , more importantly, the coal seam mainly plays the role of a water flow channel during drainage, that is, the water in the aquifer flows through the coal seam to the wellbore, but cannot form an effective pressure transmission in the coal seam, so that the pressure in the coal reservoir cannot be reduced Below the critical desorption pressure, the adsorbed gas in the coal reservoir cannot be converted into free gas, and then loses the meaning of drainage, which not only causes waste of the project, but also affects the confidence of the coalbed methane industry in people's minds, and restricts the coalbed methane industry. development of

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