碎软煤层井下长距离定点密闭取心技术研究  

Study on long-distance fixed-point sealed coring technology in broken-soft coal seam

作　　者：龙威成 孙四清 陈建[2] LONG Weicheng;SUN Siqing;CHEN Jian(Xi’an Research Institute Co.Ltd.,China Coal Technology and Engineering Group Corp.,Xi’an 710077,China;Huainan Mining Industry(Group)Corp.,Ltd.,Huainan 232001,China)

机构地区：[1]中煤科工集团西安研究院有限公司,陕西西安710077 [2]淮南矿业(集团)有限责任公司,安徽淮南232001

出　　处：《煤田地质与勘探》2022年第8期93-98,共6页Coal Geology & Exploration

基　　金：天地科技股份有限公司科技创新创业资金专项项目(2020-TD-MS010)。

摘　　要：随着矿井采掘、钻探等技术的快速发展和矿井提能增效的需求日增,区域超前探测煤层瓦斯含量的需求越来越迫切。近年来研发的井下长钻孔高压水密闭取心瓦斯含量测定技术已应用于中硬煤层矿区,效果显著,但在碎软煤层中应用存在局限性。针对采用现有定向钻孔高压水密闭取心技术进行碎软煤层取心时,存在煤心易冲散、孔壁易坍塌、喷孔、取心率低、安全风险大的问题,并结合矿井钻取含原始水分煤样的需求,提出采用“气体取心钻进+气体输送封堵球+高压水与气体联合密闭煤心”的双循环介质碎软煤层井下长距离定点密闭取心技术工艺,研发了基于井下压风取样钻进的长距离干式密闭取心系统,以压风代替压水用于钻孔排渣、取心钻头冷却和封堵球输送;以风和水两种介质组合打压驱动密闭取心装置在孔内关闭。选取淮南矿区某矿同一区域的主采煤层进行试验,碎软煤层井下长距离定点密闭取心瓦斯含量测值为6.65~7.82 m^(3)/t,常规取心瓦斯含量测值为5.11~6.45 m^(3)/t。工程试验表明,碎软煤层井下长距离定点密闭取心技术为碎软煤层井下长距离测定瓦斯含量提供了一种新途径,实现碎软煤层井下精准定点、长距离瓦斯含量精确测定,可解决碎软煤层井下大区域探测瓦斯赋存信息需求,保障矿井安全高效生产。With the rapid development of mining,drilling and other technologies in the field of coal mine and the in-creasing demand for enhancing production and profit in the coal mine,the demand is increasingly urgent for detection of coal seam gas content in the initial stage.In recent years,the gas content measurement technology of underground long borehole high-pressure water sealed coring has been applied in the medium hard coal seam mining area with remarkable effects,but its application is limited in broken-soft coal seam.A number of issues are encountered that easy breakup of coal core sample,easy wall collapse of the bore hole,gas inrush from borehole,low success rate for coal sample coring,and large risk,when the existing coring technology through directional drilling and sealed high-pressure water is em-ployed in the broken-soft coal seam.In order to solve the aforementioned issues and meet the demand of coal samples containing original moisture,a long-distance fixed-point closed coring technology process was proposed to use"gas cor-ing drilling+gas conveying plugging ball+high-pressure water and gas combined sealing coal core"in the soft coal seam with double circulation medium.A long-distance dry closed coring system is proposed through downhole pressur-ized air sampling drilling,in which pressurized air is used instead of pressurized water for drilling slag discharge,core bit cooling and plugging ball transportation;air and water are combined to press.The sealed coring device in the hole is closed through the drive from a combination of wind and water.The main coal seam in the same area of a mine in Huainan mining area is selected for testing.The gas content of long-distance fixed-point closed coring in broken-soft coal seam is measured as 6.65~7.82 m^(3)/t,while the gas content of conventional coring is measured as 5.11~6.45 m^(3)/t.It is found that the gas content of airtight coring samples is generally higher than that of conventional coring samples.The research shows that the long-distance fixed-point clo

关 键 词：密闭取心 定点取心 碎软煤层 瓦斯含量 压风钻进 

分 类 号：TD712[矿业工程—矿井通风与安全]