摘要
中国陆相页岩气资源潜力较大。与海相页岩相比,陆相页岩气层具有厚度薄、脆性矿物含量低、黏土矿物含量高、压力低等特点,海相页岩气的开发技术(特别是压裂技术)并不完全适用。为此,针对陆相页岩气层的储层特征和压裂改造难点,分析了CO2泡沫压裂技术、CO2增能压裂技术和液态CO2压裂技术的特点,并在鄂尔多斯盆地中生界延长组长7段页岩气层开展了液态CO2压裂、CO2增能压裂应用试验。结果表明:纯液态CO2在2.0m3/min排量下可压开长7段页岩气层,压后排液迅速,24h后即点火可燃;同时,CO2增能压裂能显著提高压裂液返排速度和返排率,缩短排液周期,有利于陆相页岩气的勘探开发。此外,根据目前国内压裂设备和技术现状以及环保问题,提出了陆相页岩气层CO2压裂技术今后的应用和发展思路。
China boasts of abundant terrestrial shale gas resources. Compared with marine shale, terrestrial shale has smaller thick- ness, lower content of brittle minerals, higher content of clay minerals, and lower pressure. Hence, the development technology for marine shale gas, especially the fracturing technology, is not entirely applicable to terrestrial shale. To this end, aimed at the reser- voir characteristics and fracturing difficulties, the features of liquid CO2 foam and CO2 energized fracturing technology were ana- lyzed, and their application tests were carried out in the gas shale in the Chang-7 Member of Mesozoic Yangchang Fm in the Ordos Basin. The application results showed that pure liquid CO2 at a discharge rate of 2.0 m3/min was capable of fracturing shale gas res ervoirs in Chang 7 Member with a rapid liquid unloading, and ignition could he conducted after 24 h. Meanwhile, CO1 energized frac turing greatly improved the fracturing fluid flowback speed and rate to shorten the liquid unloading period, which all benefited the terrestrial shale gas exploration and development. Moreover, based on the analysis of the state-of-the art of fracturing technologies and facilities in China, the application prospect and development idea were presented of the CO2 fracturing technology applied in ter- restrial shale gas development.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2014年第1期64-67,共4页
Natural Gas Industry
基金
国家科技支撑计划项目"陕北煤化工CO2捕集
埋存与提高采收率技术示范"(编号:2012BAC26B00)
陕西省科学技术研究发展计划项目"液态CO2压裂工艺优化设计理论研究"(编号:2011KJXX-57)
陕西省科技统筹创新工程计划项目"陆相页岩气资源地质研究与勘探开发关键技术攻关"(编号:2012KTZB03-03)
关键词
页岩气
陆相页岩
CO2增能压裂
液态CO2压裂
应用
试验
鄂尔多斯盆地
shale gas, terrestrial shale, marine shale, CO2 energized fracturing, liquid CO2 fracturing, application, test, Ordos Basin
