Research And Application Of Coal Seam Water Injection Mechanism With Surfactant

Coal seam water injection is widely used in coal mining because of its simple operation and low cost.The hydrophilicity of Surfactant,commonly used as a water injection additive during water injection,can significantly increase the effect of water injection.With the increase of mining depth,the occurrence state of coal seam is more complex,and the change of coal seam wettability by traditional Surfactant is less and less,which can not achieve the expected effect.Therefore,in view of the fact that the effect of coal seam water injection is not good in deep mining,the mechanism of Surfactant increasing the effect of coal seam water injection is studied,and the reasons of the effect are analyzed,so as to provide theoretical guidance for developing efficient wetting agents.In this paper,SDBS and IDS water injection experiments were carried out to study the laws of mineral dissolution and physical and mechanical properties of coal under different time and concentration.The results are as follows:(1)the determination of ions in the soaking solution by ICP-AES(Inductively coupled plasma atomic emission spectroscopy-RRB-shows that the solubility of minerals contain Kng k is the highest when the concentration SDBSSDBS is 0.20wt% and the soaking time is 8 days;When IDS concentration was 0.20wt% and soaking for 12 days,the mineral dissolvability of Ca was the highest,and when IDS concentration was 0.20wt% and soaking for 12 days,the mineral dissolvability of MG was the highest The dissolved ability of minerals containing Al was the highest when IDS concentration was 0.15 wt% and soaked for 12 days,and the dissolved ability of minerals containing Fe was the highest when IDS concentration was 0.20 wt% and soaked for 8 days.(2)through nitrogen adsorption experiment,it is found that IDS and SDBS can effectively increase the porosity of coal,and IDS has more obvious effect on the increase of porosity,which makes the coal form new pore structure.(3)through the detection of the water content of the soaked coal,it was found that the water content of the two groups of experimental coal reached saturation under the condition of 0.20wt% concentration and soaking for 8 days,and the effect of IDS on the water content of the soaked coal was better than that of SDBS.(4)it is found that the uniaxial compressive strength,impact energy index and dynamic failure time of coal have certain regularity with the use concentration and soaking time of IDS and SDBS,i DS is more beneficial to decrease the uniaxial compressive strength and impact energy index of coal,and increase the dynamic failure time of coal,and the change of mechanical properties of coal is more obvious than SDBS.The purpose of adding SDBS is to decrease the hydrophobicity of coal seam surface,increase the hydrophilicity and surface activity,and make the water enter the coal body more easily,increasing the contact area of water and the surface activity of coal seam from the inside of coal increases the water content of coal seam,thus increasing the permeability of coal seam.IDS and SDBS can increase the permeability of coal seam in different degree by increasing the porosity and surface tension of coal seam,and IDS can effectively open the pores of coal seam in the process of water injection in deep and low permeability coal seam,improve the permeability,for deep mining coal seam water injection effect is not good to provide solutions.