塔里木盆地库车坳陷南斜坡新和地区白垩系亚格列木组沉积模式及油气意义

Depositional model and petroleum significance of the Cretaceous Yageliemu Formation in Xinhe area on the southern slope of Kuqa Depression, Tarim Basin

周学文 林会喜 郭景祥 姚威 张坦 周学慧 罗亮

ZHOU Xuewen LIN Huixi GUO Jingxiang YAO Wei ZHANG Tan ZHOU Xuehui LUO Liang

中国石化 石油勘探开发研究院, 北京 102206 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 214126 新疆大学 地质与矿业工程学院, 乌鲁木齐 830017

Petroleum Exploration & Production Research Institute, SINOPEC, Beijing 102206, China Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China School of Geology and Mining Engineering, Xinjiang University, Urumqi, Xinjiang 830017, China

近年来，塔里木盆地库车坳陷南斜坡新和地区钻井揭示，白垩系亚格列木组在地层—岩性圈闭领域油气显示活跃、勘探潜力大，是下步战略突破的重要方向。基于岩心、测录井和三维地震资料，综合利用岩心相、测井相、小波变换、“印模法”古地貌恢复、地震相、地震属性及相干体切片的分析方法，对新和地区亚格列木组系统开展了层序与古地貌控制下的沉积体系研究。新和地区发育2种古地貌类型，即西侧多级坡折带斜坡古地貌和东侧逆冲断崖古地貌。亚格列木组可划为一个三级层序SQ1，其中包括低位域、湖侵域和高位域，分别对应该组3个逐期超覆于西侧斜坡的地震反射。亚格列木组在西侧多级坡折带斜坡之上发育低位域斜坡扇和高位域扇三角洲沉积，在东侧逆冲断崖之下发育湖侵域—高位域近岸水下扇沉积，断崖之上的侵蚀沟谷作为补给水道为其供源。新和地区发育三叠系克拉玛依组原地成熟烃源岩，且处于远源油气运移指向区，油气源和成藏条件优越。分布于逆冲断崖北侧的低位域斜坡扇和湖侵域—高位域近岸水下扇等“源上”地层—岩性圈闭勘探潜力大，可作为该区下一步隐蔽油气勘探的主要目标。

In recent years, drilling in Xinhe area on the southern slope of Kuqa Depression, Tarim Basin revealed that the Cretaceous Yageliemu Formation has active hydrocarbon display and high exploration potential in the field of stratigraphic-lithologic traps, which is an important direction for the next strategic breakthrough. Based on the core, well logs, drill cuttings and 3D seismic data, this paper integrated the analytical methods of core facies, electrofacies, wavelet transform, "impression method" paleogeomorphic restoring, seismic facies, seismic attributes, and coherence cube slicing to study the depositional system of the Cretaceous Yageliemu Formation in Xinhe area under the sequence stratigraphic and paleogeomorphic controls. The study shows that there are two types of paleogeomorphology developed in Xinhe area: (ⅰ) western multi-stage slope breaks, and (ⅱ) eastern thrust cliff paleogeomorphology. The Cretaceous Yageliemu Formation can be classified as a third-order sequence SQ1, which includes the lowstand systems tract (LST), transgressive systems tract (TST) and highstand systems tract (HST), corresponding to the three-phase seismic reflections of this formation overlying the western slope, respectively. The LST slope fans and HST fan deltas of the Yageliemu Formation were deposited above the western multi-stage slope breaks, and TST-HST subaqueous nearshore fans were deposited below the eastern thrust cliff, with erosional valleys on the cliff serving as the feeder channels and providing sources for the subaqueous fans. In situ mature hydrocarbon source rocks of the Triassic Karamay Formation are developed in Xinhe area, which is the migration direction of oil and gas far away from hydrocarbon source, indicating excellent source rocks and reservoir forming conditions. The stratigraphic-lithologic traps of the LST slope fan and TST-HST subaqueous nearshore fan located in the northern part of the thrust cliff are lying on the Triassic source rocks and have great exploration potential, which can serve as the main targets for the next subtle oil and gas exploration in this area.

中石化科技部科技攻关项目“库车坳陷斜坡带地层岩性油气藏形成条件与目标优选” P21049-1

https://doi.org/10.11781/sysydz202302266