Study On The Influence Law Of Electrical Characteristics Based On Coal Petrophysical Factors

With the continuous increase of the depth and scale of coal mining in China,the frequency of coal mine disasters also increases,resulting in greater harm.The safety of coal mine production is related to the stability of national energy supply and the safety of workers' life,so it is of great significance to study the prediction methods of various mine disasters.People have carried out in-depth research and analysis on all kinds of methods to predict coal mine disasters,among which resistivity method is also used to predict coal mine disasters.Resistivity method can detect fault fracture zone,karst development zone,aquifer,geological structure and coal rock dynamic disaster by taking advantage of the different conductivity of various rocks in the earth's crust and by exploring and revealing the distribution law of stable electric current field artificially established underground.The physical properties of coal(such as metamorphism degree,composition of coal and rock,humidity,temperature,etc.)are one of the main factors affecting resistivity.Therefore,it is of great significance to the safety production of coal mine to deeply study and reveal the influence law of coal petrophysical factors on resistivity and establish the correlation between resistivity and coal petrophysical properties.This paper takes coal resistivity as the research object and collects five kinds of coal with different metamorphic degrees in different mining areas in China.In the sampling sites,Dashiquan mine is long-flame coal,Hongxing mine is fat coal,Dongli mine is coking coal,Laowa Mine is lean coal and Baiyangling mine is anthracite.Through the experimental testing system,the resistivity of coal under the influence of different physical properties(different metamorphic degree,different coal rock composition,different humidity,different temperature,different test frequency)was measured.The experimental results can provide basic theoretical guidance for the prevention and control of coal mine water damage and fire.With the increase of humidity,the resistivity of coal samples shows a decreasing trend and the law is obvious.The coal resistivity and its change law can be used to detect the aquifer and predict the mine water damage.The resistivity of coal decreases with the increase of temperature,and the higher the temperature is,the more stable the resistivity is,which can be used to calculate the temperature of abandoned coal in goaf and judge the danger area of spontaneous combustion.In this paper,the resistivity field test is carried out in a mine,and the risk of water inrush in front of the detected roadway is predicted by analyzing the change rule of the resistivity chart obtained from the test.The paper has 33 figures,9 tables,and 66 references.