柴达木盆地北缘石炭系克鲁克组页岩气形成条件分析

Generation conditions of shale gas in Carboniferous Keluke Formation, northern Qaidam Basin

仰云峰 饶丹 付小东 申宝剑 许锦

Yang Yunfeng Rao Dan Fu Xiaodong Shen Baojian Xu Jin

中国石化 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214151 2.中国石油 杭州地质研究院, 杭州 310023

Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214151, China 2. PetroChina Hangzhou Research Institute of Geology, Hangzhou, Zhejiang 310023, China

以柴达木盆地北缘野外剖面地质调查为基础,结合相关钻井、露头资料和前人研究成果,综合分析柴北缘上石炭统克鲁克组富有机质泥页岩展布、有机地球化学、矿物组成、储集空间、含气性等方面特征。结果表明,克鲁克组页岩有机质丰度高,w(TOC)为0.28%~11.93%,平均值大于2%,Ro为0.9%~1.44%,平均为1.12%,处于有机质热演化的成熟阶段,页岩有效厚度为30~150 m,脆性矿物含量大于40%,微米—纳米级裂缝和孔隙发育,含气量为1.01~2.85 m3/t,平均为1.87 m3/t,尕丘凹陷、欧南凹陷和德令哈断陷有利于页岩气形成与富集,是克鲁克组页岩气勘探开发的有利区。

Based on outcrop geological survey in the northern Qaidam Basin and integrated with other data of drillings, outcrops and previous research results, the Carboniferous Keluke Formation shale gas accumulation conditions and core area selection were investigated by delineating regional distribution of gas shale, organic geochemical features, mineral compositions, pore system and gas content in gas shale. Shale in the Keluke Formation is rich in organic matter. The TOC value ranges from 0.28% to 11.93%, and is over 2% in average. The thermal maturity value (Ro) ranges from 0.9% to 1.44%, and is 1.12% in average, indicating for the mature stage of organic matter thermal evolution. The available thickness of shale in the Keluke Formation is 30-150 m. The content of brittle minerals is greater than 40%. Pore systems of micro and nano scales are well-developed. Gas content ranges from 1.01 to 2.85 m3/t, and is 1.87 m3/t in average. The Gaqiu Sag, Ounan Sag and Delingha Fault Depression are favorable for the generation and accumulation of shale gas, hence are the targets for shale gas exploration in the Keluke Formation.

国土资源部项目"全国页岩气资源潜力调查评价及有利区优选"的子项目(XB2011-04)资助。

https://doi.org/10.11781/sysydz201406692