Extraction mode and engineering demonstration of pressure relief three-dimensional of multi-coal seams in Pingdingshan mining area
李延河倪小明贾晋生
LI Yanhe;NI Xiaoming;JIA Jinsheng
平顶山天安煤业股份有限公司中国平煤神马控股集团有限公司河南理工大学 能源科学与工程学院河南超蓝能源科技有限公司
平顶山矿区多煤层发育、含气层段多,仅靠井下进行瓦斯治理工程量大、难度高。为了开辟平顶山矿区瓦斯抽采新模式,达到“采一层抽多层”的目的,采用气测录井与含气量测试相结合的方法精准判识了煤系主要含气层段和含气量;采用体积法评价了东部5对矿井采动区和采空区的煤系气资源量。基于“O”形圈理论和“防−抗−让”思想,分别优化设计了采动井、采空井的井位、层位和井身结构,构建了采动区、采空区多煤层卸压立体抽采模式并进行了工程示范。结果表明:① 二1煤层顶板200 m范围内存在四煤组、三煤组、二1煤层顶板60 m范围内的砂岩/泥质砂岩互层段等3处主要含气段。平顶山矿区东部5对矿井的采动区和采空区资源量分别为26.36×108 m3和20.00×108 m3。②采动井最佳井位为0.17~0.28倍采长,且靠近回风巷条带区域;走向上,采动井的间距一般为80~100 m。创建了“大口径、避开岩体变形强烈区、P110梯型扣套管”的采动直井稳孔技术体系和“下行水平轨迹+提高套管强度”的采动L型水平井稳产技术体系,保证了产气通道的畅通性。采空井一般布置在距离回风巷30~50 m的区域,完钻位置一般为二1煤层顶板40~60 m的范围;筛管布置在四煤段顶板至裂隙带底部。③建立了“地面采动直井/定向井−采动L型水平井−采空井”联作的卸压立体抽采模式,实现了多气源立体抽采。截至2024年4月30日,累计抽采纯量达
There are many coal seams and gas-bearing strata in Pingdingshan mining area, and the amount of underground gas control project is large and difficult. In order to establish a new model of gas drainage in Pingdingshan and achieve the purpose of mining one layer and extracting multiple layers, the main gas-bearing layers and gas content of coal measures were accurately identified by combining gas logging and gas content testing. The coal measures gas resources in the mining area and goaf of five pairs of mines in the east are evaluated by the volume method. Based on the theory of “O-ring” and the concept of “prevent-allow-resist”, the positions of wells and the positions of layers, and wellbore structures of the mining wells and of goaf wells were optimized respectively. A multi-coal seam pressure-relieving three-dimensional extraction model of the active mining and goaf area constructed and an engineering demonstration was carried out. The results show that: ① There are three main gas bearing sections within 200 m of the roof of coal seam Ⅱ1, including the fourth coal group, the third coal group, and the sandstone and mudstone interbedded section within 60 m of the roof of coal seam Ⅱ1.The resources of mining area and goaf area in the eastern part of Pingdingshan mining area are 26.36 × 108 m3 and 20.00 × 108 m3 respectively. ② The optimal wells position are 0.17-0.28 times the length of the coal mining face and close to the return airway strip area. The spacing between mining wells is generally 80-100 m. A stable drilling technology system for mining vertical wells with “large diameter, avoiding areas of strong rock deformation, P110 ladder type casing” and a stable production technology system for mining L-shaped horizontal wells with “downward horizontal trajectory+ increasing casing strength” was established, which can ensure the smoothness of gas production channels. The goaf well is generally arranged in an area 30-50 m away from the return airway, and the drilling position is generally within the range of 40-60 m from the roof of the Ⅱ1 coal seam; The sieve tube is arranged from the top plate of the fourth coal section to the bottom of the fracture zone. ③ A long-term stable and efficient extraction technology system for ground wells in goaf areas was established, and a pressure-relieving three-dimensional extraction mode of “ground extraction vertical well/directional well-ground extraction L-shaped horizontal well-goaf well” and realizing multi-gas source three-dimensional extraction has been formed. Up to April 30th, 2024, the cumulative extraction volume reached 52.588 million m3, and the total utilization reached 37.354 million m3, taking the lead in realizing the industrial development of coal measures gas in Henan Province, and playing a significant role in demonstrating and leading.
煤系气多煤层卸压立体抽采模式采动区采空区平顶山矿区
coal bearing gas;pressure relief of multiple coal seams;three-dimensional extraction mode;active mining area;goaf area;Pingdingshan mining area
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会