Dynamic permeability predicting method and device of inclined coal seam

Abstract

An embodiment of the application provides a dynamic permeability predicting method of an inclined coal seam and a dynamic permeability predicting device of the inclined coal seam. The method includessteps of confirming an equivalent geothermal gradient of a coal seam according to the coal seam buried depth and the coal seam temperature; confirming reservoir gap pressure of the coal seam under thedevelopment stage, and confirming the effective stress of the coal seam according to the reservoir gap pressure and the coal seam confining pressure; confirming function without dimension relation offactors of methane gas testing coal seam permeability, and confirming a linear regressive model of the coal seam permeability according to the function without dimension relation and the coal seam permeability data under different temperature and stress load conditions; substituting the equivalent geothermal gradient of the coal seam and the horizontal effective stress of the coal seam to the linear regressive model, and acquiring a dynamic permeability predicting model of the inclined coal seam; predicting the dynamic permeability of the coal seam according to the dynamic permeability predicting model of the inclined coal seam. According to the embodiment of the application, the method and the device can improve the accuracy predicting dynamic permeability of the inclined coal seam.

Description

technical field [0001] The present application relates to the technical field of coalbed methane development, in particular to a method and device for predicting dynamic permeability of inclined coal seams. Background technique [0002] Coalbed methane, as an alternative energy source to conventional oil and gas resources, has become an important part of the world's energy structure. Permeability, as an indicator to measure the ability of porous media to allow fluid to pass through, is one of the key indicators that affect the production of coalbed methane wells and determine the recoverability of coalbed methane reservoirs. On the one hand, when predicting the production of coalbed methane wells, it is necessary to determine and predict the migration velocity of coalbed methane, and the fluid flow rate depends to a large extent on the size of the reservoir permeability; The most commonly used parameters for mining economic value. However, because the texture of coal rock ...

AI Technical Summary

Problems solved by technology

However, because the texture of coal rock is fragile, gas adsorption and desorption have a great influence on the permeability of the reservoir, and the permeability of the coal reservoir is the most difficult parameter to measure.

[0003] At present, the existing permeability model based on elastic mechanics is to simplify the calculation process, so the accuracy of its permeability prediction is difficult to guarantee

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