Coal rock flow field in-situ fluorescent bacterium microscopic tracing method

Abstract

The invention discloses a coal rock flow field in-situ fluorescent bacterium microscopic tracing method, and belongs to a gas-containing coal seam hydraulic measure effect evaluation method. According to the microscopic tracing method, dual-band fluorescent tracing bacteria serve as a tracing medium, primary distribution of the tracing medium in coal seam fractures is completed in a positive and negative pressure tide supply mode, and the fluorescent bacteria are small in individual size (1t; 5 [mu] m) and cannot be segmented continuously, fluorescence can be excited under irradiation of light with a specific wavelength, a dual-band fluorescence characteristic is achieved, thalli can be concentrated through centrifugation, and a sensitive factor autonomous avoidance characteristic is achieved; and further completing the distribution of the strain in the mesopores by utilizing the approach and avoidance characteristics of the sensitive factors of the tracer bacteria. The method has the advantages that (1) infinite dilution of the tracing medium due to coal seam water interference is avoided; (2) the tracer medium is easy to observe and high in recognition sensitivity due to the characteristic that the dual-wavelength can be excited to emit fluorescence; and (3) the medium can be fully distributed in a mesoporous fissure space, and the sensitivity of hydraulic measure effect evaluation is higher.

Description

technical field [0001] The invention relates to a method for evaluating the effect of hydraulic measures for gas-containing coal seams, in particular to a method for in-situ fluorescent bacteria microscopic tracing in a coal rock flow field. Background technique [0002] Hydraulic measures (hydraulic fracturing, coal seam water injection, etc.) are an effective technical way to increase the permeability of coal and rock mass, promote gas desorption, and improve the effect of coal seam gas drainage. Permeability enhancement in low permeability coal seams. However, due to the colorless and odorless characteristics of water and the opaqueness of coal and rock mass, it is impossible to clearly determine the flow direction, influence range, and restrictive factors of the injected water during the implementation of the hydraulic measures technology, resulting in the implementation effect of the hydraulic measures. It has great uncertainty and uncontrollability. [0003] Evaluati...

AI Technical Summary

Problems solved by technology

[0008] Technical problem 1: The dilution effect of coalbed water and coalbed methane on the tracer leads to many tracer interference factors. When the tracer is excessively diluted, it cannot be enriched by physical methods, making it difficult to measure, thereby reducing the sensitivity of tracer technology

[0009] Technical problem 2: Affected by the water sealing effect in the mesoporous fracture space of the coal body, it is difficult for the tracer to effectively distribute in the mesoporous fracture space regardless of ion tracer or gas tracer

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