1. State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology,Shandong University of Science and Technology,Qingdao　 266590,China; 2. College of Mining and Safety Engineering,Shandong University of Science and Technology, Qingdao　 266590,China

为提高煤层瓦斯抽采效果,提出利用核磁共振(NMR)无损害测试方法,结合煤矿实际需求,从孔隙负压和表面活性剂两个方面对煤层水锁效应解除方法进行实验研究。结果表明:随孔隙负压的增加,核磁共振T2截止值可分为3个阶段:"稳定—降低—稳定"阶段。当煤层内的孔隙负压小于360.9 Pa时,煤层内的外来水会堵塞煤体孔隙,产生煤体水锁效应;当孔隙负压大于769.6 Pa时,能够消除水分对煤层孔隙的封堵,解除煤层水锁效应。在表面活性剂方面,阴离子和非离子表面活性剂溶液可以解除煤体中的水锁效应,有利于瓦斯抽采,且阴离子表面活性剂溶液解除水锁程度要大于非离子表面活性剂溶液;阳离子表面活性剂溶液会抑制煤层水锁效应的解除,阻止瓦斯在煤层中的运移,抑制瓦斯的抽采。

In order to improve the effect of coal seam gas drainage,the nuclear magnetic resonance ( NMR) testing method was used,combined with the requirements of mining reality,to conducted an experimental research on the re- moving methods of water blocking effect (WBE) from two aspects of drainage negative pressure and surfactants. The results show that the NMR works well for doing research on the removing methods of WBE. Drainage pressure,for re- moving WBE,can be divided into three stages,“ stable-decrease-stable”,according to T2 cutoff value. When drainage pressure is smaller than 360． 9 Pa,the external water will block coal pores,so that WBE arises; when negative pres- sure of gas drainage is bigger than 769． 6 Pa,it can eliminate the water blocking of coal pore and remove WBE. Anion- ic and nonionic surfactant liquor can remove WBE in coal,which is benefit to gas drainage,and anionic surfactant liq- uor can do better than nonionic surfactant liquor to remove WBE. In addition,cationic surfactant restrains the process of removing WBE,prevents gas movement in coal and restrains gas drainage. The research offers a theoretical guidance for mine gas drainage.

国家自然科学基金资助项目(51704186)；山东省自然科学基金资助项目(ZR2016EEQ18)；中国博士后科学基金面上资助项目(2017M622235)；

NI Guanhua,LI Zhao,XIE Hongchao. Experimental research on the methods to remove water blocking effect based on nuclear magnetic res- onance testing[J]. Journal of China Coal Society,2018,43(8):2280-2287.