辽东湾北部东营组同沉积断裂对沉积充填控制

Control of the Syndepositional Fault on Depositional Fillings of the Dongying Formation in Northern Liaodong Bay

夏世强 林畅松 杜晓峰 李俊乾 李虹

XIAShiqiang LINChangsong DUXiaofeng LIJunqian LIHong

华北理工大学矿业工程学院, 河北 唐山 063210 中国地质大学(北京)教育部海相储层演化与油气富集机理重点实验室, 北京 海淀 100083 中国地质大学(北京)海洋学院, 北京 海淀 100083 中海石油(中国)有限公司天津分公司, 天津 塘沽 300459 中国石油大学(华东)地球科学与技术学院, 山东 青岛 266580

College of Mining Engineering, North China University of Science and Technology, Tangshan, Hebei 063210, China MOE Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism, China University of Geosciences(Beijing), Haidian, Beijing 100083, China School of Ocean Science, China University of Geosciences(Beijing), Haidian, Beijing 100083, China CNOOC China Limited, Tianjin Branch, Tanggu, Tianjin 300459, China School of Geosciences, China University of Petroleum(East China), Qingdao, Shandong 266580, China

为了探讨东二早期同沉积断裂对沉积充填的控制作用，利用辽东湾拗陷北部区域的岩芯分析数据、钻井、测井及地震资料，对东二下亚段层序划分、同沉积断裂活动性变化及其对轴向曲流河三角洲湖底扇沉积充填演化的控制作用进行了分析。研究结果表明，东二下亚段为一个三级层序，根据最大泛湖面可在内部划分为低位+水进体系域和高位体系域。低位+水进体系域，曲流河三角洲发育在同沉积断裂活动引起的高沉降速率阶段，断裂两侧地层厚度差异大，滑塌形成的浊积在地震上表现为强振幅、低频、高连续性特征，根据钻测井标定，测井曲线呈中高幅度齿状为主，岩性以粉砂岩和泥岩为主，没有明显的沉积构造。而高位域曲流河三角洲形成于同沉积断裂活动所造成的低沉降速率阶段，断裂两侧地层厚度差异小，滑塌形成的浊积在地震上表现中弱振幅蠕虫状杂乱反射特征，测井曲线呈中低幅度钟形或者漏斗形为主，岩性以中粗砂岩为主，局部含砾，沉积构造以软沉积变形构造为主。

To investigate the control of the syndepositional faults on the depositional fillings in the lower E, regional core analysis data, drilling logs, and seismic data from the northern section of the Liaodong Bay Depression were used to analyze sequence division, changes in activity level of synsedimentary faults, and controlling effect on the axial meandering river deltasublacustrine fan sedimentary filling evolution in the lower E segment layer. The lower E segment layer was shown to be comprised of three layers that can be divided into lowstand+transgressive system tracts and highstand systems tracts according to the flooding surface. In the lower+transgressive system tracts, the meandering river delta developed in the high sedimentation rate stage due to syndepositional fault activity. The difference in stratum thickness between the two sides of the fault was significant, and the turbidity formed by the slump showed strong amplitude, low frequency, and high continuity on seismic section. According to the drill logging calibration, the logging curve exhibited a tooth shape with medium to high amplitude and the lithology was mainly siltstone and mudstone without obvious depositional structure. The meandering river delta in the highstand systems tracts formed in the low sedimentation rate stage due to syndepositional fault activity. The difference in the stratum thickness between the two sides of the fault was negligible, and the turbidity formed by the slump was characterized by a vermicule chaotic reflection with weak amplitude on seismic section. The logging curve exhibited bell or funnel shapes of medium to low amplitude and the lithology was predominantly medium coarse sandstone with gravel present in local areas. In addition, the depositional structure was shown to be dominated by soft-sediment deformation structure.

10.11885/j.issn.1674-5086.2018.07.18.02