摘要
中国碎软低渗煤层发育,气含量高,资源潜力大,瓦斯压力大、煤岩力学强度低、顺煤层钻进成孔困难,"有气难出"一直是困扰这类煤层气高效开发和矿井瓦斯治理的关键科学技术问题。芦岭煤矿8煤层为碎软、高瓦斯、突出、低渗、难抽采煤层,顶板可钻性较好。引进水平井分段压裂技术,沿煤层顶板施工水平井,采用"泵送桥塞封隔分段、多段多簇定向射孔、逐段分步定向压裂"等成套开发技术,以及"先低后高、先细后粗"的加砂工艺,适时应用段塞式加砂技术,在煤层中形成了多组具有高渗流能力的北东向垂直主裂缝带。经过精细排采,创造了煤层气水平井日产气量超万立方米的纪录。碎软低渗煤层顶板水平井分段压裂技术的成功应用,突破了"构造煤是煤层气开发禁区"的观念,填补了难抽采突出煤层区地面煤层气高效开发和矿井瓦斯治理技术的空白。
Broken soft and low permeability coal seam, with high gas content, high gas pressure, grant re- source potential, and low mechanical strength, developed well in China. Formation of hole along the coal seam drilling is difficult, and the key science and technology problem in CBM efficient development and the mine gas control of this coal seam area have always been difficult to extract gas.No.8 coal seam of Luling coal mine is in broken soft, high gas, outburst, low permeability, difficult extraction, easy drill ability of roof.Introducing horizontal well and multistage fracturing techniques, constructing horizontal well along the coal seam roof,using a complete set of developing techniques, pumping bridge plug multistage, multi- stage clustering directional perforation,piecewise directional fracturing step by step,and adopting the sand technologies of first low to high,first coarse to fine,applying slug-style sand technology duly,multiple sets of north-east main vertical fracture belts with high seepage ability were formed in the coal seam.Through fine drainage management technology, the horizontal well creates a record that daily CBM production is more than ten thousand cubic meters.The successful application of multistage fracturing in horizontal well along the roof of broken soft and low permeability coal seam,breaking through the concept that ＂structure coal is forbidden zone to develop CBM＂, filling the techniques gap in surface CBM efficient development and coal mine gas control of difficult extracting coal seams area.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2017年第12期1873-1881,共9页
Natural Gas Geoscience
基金
国家科技重大专项课题(编号:2016ZX05045-002)资助
关键词
分段压裂
定向射孔
水平井
碎软低渗煤层
芦岭煤矿
Multistage fracturing
Oriented perforating
Horizontal well
Broken soft and low permeability coal seam
Luling coal mine
