二连盆地阿尔凹陷东部陡坡带腾一下亚段重力流沉积特征

Sedimentary characteristics of gravity flow from lower submember of the first Member of Tengger Formation in the eastern steep slope belt of Aer Sag, Erlian Basin

王予帆 尹天豪 丁毅 纪友亮 马刚 杨旭

中国石油大学（北京）油气资源与探测国家重点实验室，北京 102249 中国石油华北油田公司二连分公司，河北 任丘 062550 中国石化石油物探技术研究院，江苏 南京 211103

State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing 102249, China Erlian Branch Company, Huabei Oilfield Company, PetroChina, Renqiu 062550, China Geophysical Research Institute, SINOPEC, Nanjing 211103, China

基于岩心、测井和三维地震资料分析，对二连盆地阿尔凹陷东部陡坡带下白垩统湖底扇沉积特征及其控制因素进行了系统的分析，建立了研究区湖底扇发育模式。研究区重力流沉积类型主要有滑塌、砂质碎屑流、颗粒流、浊流4种沉积类型；受阿尔凹陷东部陡坡带古地貌、物源供给以及外界触发机制的共同影响，多期重力流在研究区湖盆形成湖底扇；近源区湖底扇沉积以滑塌、厚层砂质碎屑流和颗粒流为主，湖底扇中部主要充填砂质碎屑流成因的厚层砂岩，随着流体的运移和沉降，砂质碎屑流逐渐转变成远端浊流，在湖底扇末端主要沉积正粒序层理的浊积岩和湖相泥岩。

Based on the analysis of core, logging and 3D seismic data, the sedimentary characteristics and its controlling factors of Lower Cretaceous  sublacustrine fan in the eastern steep slope belt of Aer Sag, Erlian Basin were systematically analyzed, and the development model of sublacustrine fan in the study area was established. The types of gravity flow deposition in the study area mainly include landslides, sandy debris flows, particle flows, and turbidity currents. Affected by the palaeogeomorphology, provenance supply and external trigger mechanism in the eastern steep slope belt of Aer Sag, multi-phase gravity flow forms a sublacustrine fan in the lake basin of the study area. The sublacustrine fan deposition near the source area are mainly dominated by landslides, thick sandy debris flows and particle flows. The middle part of the sublacustrine fan is mainly filled with thick sandstone caused by a large set of sandy debris flow. As the fluid moves and settles, the sandy debris flow gradually transforms into remote turbidity current. At the end of the sublacustrine fan, turbidite with positive grain sequence bedding and lacustrine mudstone are mainly deposited.

10.6056/dkyqt202204009