摘要
对松软煤层进行穿层瓦斯抽采时,在采动影响下,易发生钻孔收缩变形和坍塌、花管堵塞等问题,导致瓦斯抽采效率低、抽采周期延长,甚至需要补孔进行二次瓦斯抽采。为此,研究一种新型自膨胀护孔抗压花管。新型自膨胀花管外围的弹簧钢片在钻孔内膨胀成球体,可有效抵御钻孔变形,弹簧钢片外围的钢丝网布可阻挡煤体坍塌,防止花管堵塞,从而在抽采中后期使煤层与花管之间仍有较大的空间供瓦斯径向流动与球向流动,有助于瓦斯由吸附态转化为游离态,提高瓦斯抽采效率。现场试验表明,在瓦斯抽采初期,采用常规花管的对照组与采用自膨胀花管的试验组相比较,平均瓦斯抽采浓度接近,但在抽采50d之后的中后期,试验组的瓦斯抽采浓度仍能保持在20%以上,瓦斯涌出量是对照组瓦斯抽采浓度的4倍以上,因此,新型自膨胀花管具有较好的应用价值。
During gas extraction through soft coal seams,under the influence of mining,it is prone to occur borehole shrinkage deformation and collapse,flower tube blockage,and other problems,resulting in low gas extraction efficiency,prolonged extraction cycle,and even the need for additional holes for secondary gas extraction.In order to solve the above problems,a self expanding and pressure-resistant flower tube for hole protection was studied.The spring steel sheet outside the new flower tube expanded into a sphere in the borehole,which can effectively resist the borehole deformation,and the outer steel wire mesh fabric prevented coal collapse and flower tube blockage.Therefore,there was still a large space for gas radial flow and spherical flow between the coal seam and the flower tube in the middle and late stages of extraction,which helped the gas to be transformed from the adsorption state to the free state and improved the gas extraction efficiency.The field test shows that in the early stage of gas extraction,the average gas extraction concentration of the control group using conventional flower tube is close to that of the experimental group using self-expanding flower tube.However,in the middle and late stage after 50days of extraction,the gas extraction concentration of the experimental group can still be maintained at more than 20%,and the gas emission is more than 4times that of the control group.Thus,the new self-expanding flower tube has a good application value.
作者
王振锋
白志强
王宇
王琼霄
曹良超
WANG Zhenfeng;BAI Zhiqiang;WANG Yu;WANG Qiongxiao;CAO Liangchao(School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo,Henan 454003,China)
出处
《矿业研究与开发》
CAS
北大核心
2024年第1期161-167,共7页
Mining Research and Development
基金
国家自然科学基金项目(41872188).
关键词
瓦斯抽采钻孔
自膨胀花管
瓦斯涌出量
瓦斯抽采浓度
数值模拟
Gas extraction borehole
Self-expanding flower tube
Gas emission amount
Gas extraction concentration
Numerical simulation
