摘要
上扬子地区下志留统龙马溪组页岩气具有较好的勘探前景。早志留世龙马溪期为浅水．深水陆棚沉积环境，笔石页岩尤为发育。利用最新的钻井资料以及野外露头等样品的分析测试资料，以龙马溪组富有机质页岩分布特征、有机地球化学特征、储集条件、保存条件及页岩含气性等为重点，研究龙马溪组页岩气的成藏条件与资源潜力。研究表明上扬子地区下志留统龙马溪组页岩底界深度2000～8000m（一般在4500m以内），分布广泛，连续沉积厚度大（一般在50—500m）；机碳含量较高（0．15％～12．5％），有机质类型为Ⅰ—Ⅱ1型，有机质成熟度达到高-过成熟阶段；富有机质页岩脆性矿物含量高，储层空间丰富；多处勘探井中龙马溪组显示气测异常。综合研究认为宜宾-习水-正安一带和彭水-咸丰-鹤峰一带是研究区最有利勘探区带。
Shales in Longmaxi Formation of Lower Silurian in upper Yangtze region are gaining more attention with favorable exploration prospects. The depositional environment of Longmaxi Formation in the study area is shal- low or deep shelf environment,in which graptolite-rich black shale is widely developed. Based on the new drilling data and testing data of field samples, by focusing on distribution characteristics, organic geochemistry, reservoir and preservation conditions , and gas content, reservoir forming conditions and resource potential of shale in Long- maxi Formation of Lower Silurian in upper Yangtze region are studied in detail. The results indicate that buried depth of organic-rich shale in Longmaxi Formation of Lower Silurian in the study area is relatively shallow with depth of bottom between 2 000 and 8 000 m, average is 4 500 m, and the thickness ranges from 50 to 500 m. Total organic carbon content of shale ranges from 0. 15% to 12.5%, and the organic matter with Ⅰ - Ⅱ 1 kerogen is at high or over mature stage. Moreover, shale with various types of reservoir space has a higher content of brittle minerals. More importantly, shale gas were identified in some exploration wells in the study area. Then, Yibin-Xishui-Zheng＇ an area and Pengshui-Xianfeng-Hefeng area are predicted as favorable exploration regions by synthetical analysis of reservoir forming conditions and resource potential.
出处
《科学技术与工程》
北大核心
2014年第17期40-47,58,共9页
Science Technology and Engineering
基金
湖北省自然科学基金项目(2011CDB005)
中海油研究中心项目(CNOOCRC(LTD)-2010-ZHKY-018)资助
关键词
龙马溪组
富有机质页岩
成藏条件
有利勘探区带
Longmaxi Formation
organic-rich shale
reservoir forming conditions
favorable explora- tion regions
