塔里木盆地塔河油田西部斜坡区中下奥陶统古岩溶洞穴发育特征

为研究塔里木盆地塔河油田西部斜坡深切曲流峡谷区中下奥陶统的古岩溶发育条件和洞穴发育特征，基于地震及钻井资料，利用层拉平法、构造趋势面、振幅异常等方法，还原了古水文地貌条件和古岩溶水系统，划分了深切曲流峡谷区岩溶洞穴类型，构建了深切曲流峡谷背景下岩溶洞穴的发育模式。结果表明：(1)研究区发育海西早期古岩溶作用，古地貌总体东高西低，岩溶地貌单元以峡谷、溶丘和洼地为主，地表主干水系深切曲流为研究区最低的岩溶水排泄基准，地下、地表分支水系由南北平台区向中心主干汇流；(2)深切曲流峡谷区地下河洞穴识别了暗河型、伏流型、穿洞型、顺河潜流型、渗流入流型等5种类型，主要分布在不整合面以下0~90 m，穿洞型、顺河潜流型溶洞易被泥质充填；(3)深切曲流峡谷、岩溶残丘和断裂联合控制了古岩溶洞穴的发育，形成了塔河岩溶盆地海西早期深切曲流峡谷区中心汇流型岩溶洞穴模式。

Features of Middle-Lower Ordovician paleo-karst caves in western slope area,Tahe Oil Field,Tarim Basin

Seismic and drilling data were obtained to study the paleo-karst development conditions and cave developmental characteristics of the Middle-Lower Ordovician in the incised meandering canyon area on the western slope of Tahe Oilfield, Tarim Basin. Using layer leveling, tectonic trend surface, amplitude anomaly and other methods, the paleo-hydrogeographic conditions and paleo-karst fluid system were restored, the types of karst caves in the incised meandering canyon area were divided, and the development model of karst caves under the background of incised meandering canyons was re-constructed. Results showed that: (1) Early Hercynian paleo-karst was developed in the study area. The paleo-geomorphology was generally high in the east and low in the west. The karst geomorphic units were mainly valleys, karst hills and depressions. The incised meandering of the main surface water system was the lowest karst water discharge benchmark in the study area, and the underground and surface branch water systems converged from the southern and northern platforms to the central main body. (2) The underground river caves in the incised meandering canyon area were identified as subterranean river type, swallet stream type, perforated type, phreatic type along river valley and vadose type of sink hole, which were mainly distributed 0-90 m below unconformity surface. The perforated type and phreatic type along river valley were easy to be filled by mud. (3) Incised meandering canyon, karst residual hill and fault controlled the development of ancient karst caves, forming a central confluence karst cave model in the Early Hercynian incised meandering canyon area of the Tahe karst basin.