达坂城次凹二叠系页岩气地质特征与勘探潜力  

Geological characteristics and exploration potential of Permian shale gas in Dabancheng sub-sag

作　　者：张雪峰 徐最 康弘男 胡永 ZHANG Xuefeng;XU Zui;KANG Hongnan;HU Yong(Engineering Technology Company of CNOOC Energy Development Co.,Ltd.,Tianjin 300452,China;156 Exploration Team of Xinjiang Coalfield Geological Bureau,Urumqi,Xinjiang 830009,China)

机构地区：[1]中海油能源发展股份有限公司工程技术分公司,天津300452 [2]新疆煤田地质局一五六煤田地质勘探队,新疆乌鲁木齐830009

出　　处：《石油地质与工程》2023年第1期26-31,38,共7页Petroleum Geology and Engineering

基　　金：中海油能源发展重大专项(E-J613D002)。

摘　　要：柴窝堡凹陷达坂城次凹上二叠统芦草沟组泥页岩在前期勘探中已证实具备页岩气成藏条件,但勘探潜力仍不明确。基于野外剖面露头样本分析测试数据,结合区域地震、钻井及测井资料,对芦草沟组泥页岩发育情况、地球化学特征、储集条件和页岩气成藏模式进行分析。结果表明:受沉积环境的影响,达坂城次凹芦草沟组页岩分布和发育情况具有较为明显的南北部不同的特征。次凹南部地区为滨浅湖相-三角洲相沉积环境,泥页岩厚度薄,有机质丰度低,以Ⅲ型干酪根为主,不具备页岩气成藏的地质条件;次凹北部发育深湖相富有机质泥页岩,厚度较大,有机质类型以Ⅰ、Ⅱ_(1)、Ⅱ_(2)型为主,有机质丰度高,微裂隙发育,脆性矿物与黏土矿物组合优越,具备页岩气勘探潜力,但成熟度偏低,风险较大。通过区域页岩气成藏模式分析可知,达坂城次凹北部区域斜坡带断裂构造较少的部位是页岩气勘探的有利区带。The shale of Lucaogou formation from upper Permian in Dabancheng sub-sagof Chaiwopu sag has been proved to have shale gas reservoir forming conditions in early exploration, but its exploration potential is still unclear.Based on the analytical and test data of field profile outcrops, combined with regional seismic, drilling and logging data, the study on shale development, geochemical characteristics, reservoir conditions and shale gas accumulation model of Lucaogou formation has been carried out.The results indicate that affected by the sedimentary environment, the distribution and development of Lucaogou formation shale in Dabancheng sub-sag has obvious characteristics of northern-southern zone.In southern part, it is a shore shallow lacustrine delta sedimentary environment, with thin shale thickness and low organic matter abundance, dominated by type Ⅲ kerogen and have no geological conditions for shale gas accumulation.In northern part, it is a deep lacustrine organic rich shale, with large thickness.The organic matter belongs to types Ⅰ,Ⅱ_(1)and Ⅱ_(2),and has a high abundance.With developed microfractures, superior combination of brittle minerals and clay minerals, it has good potential on shale gas exploration, with low maturity and high risk.Through the analysis of regional shale gas accumulation model, it can be seen that the position with less fault structures in the slope zone in the northern part is a favorable area for shale gas exploration.

关 键 词：柴窝堡凹陷 达坂城次凹 芦草沟组 页岩气 地球化学特征 

分 类 号：TE112.221[石油与天然气工程—油气勘探]