优质烃源岩识别及其多属性反演技术定量评价——以渤海海域辽东南洼陷为例

以渤海海域辽东南洼陷为例，综合利用地球化学、测井与地震资料，建立了优质烃源岩常规地球化学参数、测井参数与地震反射三级识别标志：常规地化特征主要为总有机碳含量（TOC）大于2%，生烃潜力（S₁+S₂）大于10mg/g，镜质体反射率（R₀）大于0.5%；测井曲线具有高伽马、高电阻率、高声波时差、高中子孔隙度、低密度的特点；地震上具有低频、强振幅、连续、平行反射的特征。利用测井数据，对比交会分析、多元回归法与ΔlgR法，建立单井TOC曲线。再利用地震资料，提取地震属性，运用多元回归分析和神经网络方法进行属性优化训练，优选与TOC相关性较高的属性组合，反演得到TOC数据体。结果表明：研究区各层段的优质烃源岩整体展布范围广，厚度较大。洼陷北部优质烃源岩明显比南部厚，是该区生烃中心，南部则主要沿走滑断层呈串珠状分布，明显受到走滑断层控制。辽东南洼烃源岩发育层系较多、规模较大、生烃潜力大，是渤海海域极具勘探潜力的地区。

High-quality hydrocarbon source rock identification and quantitative evaluation with multi-attribute inversion: A case study of Liaodong south sub-sag,Bohai Bay Basin

A high-quality hydrocarbon source rock identification scheme is established based on geochemistry, logging and seismic data in the Liaodong south sub-sag, Bohai Bay Basin.For this three-grade scheme, geochemical characteristics include TOC>2%, hydrocarbon generation potential >10mg/g, and vitrinite reflectance (R₀)>0.5%.Logging curves are characterized by high gamma, high resistivity, high moveout, high neutron porosity, and low density.Seismic reflection is characterized by low frequency, strong amplitude, continuous and parallel reflection.TOC curves of single well is created with logging data, cross-plot analysis, multiple regression, and the ΔlgR method, which provides independent variables for seismic multi-attribute inversion.Multi-attributes relative to TOC are optimized with multiple regression and neural network, and are inverted into TOC volume.So quantitative TOC evaluation is realized.According to our results, high-quality source rocks are widely distributed in the south sub-sag.The north part is the hydrocarbon-generation center, in which source rocks are thicker than that the south part.Source rocks in the south part are bead-distributed along a strike-slip fault.Several-series source rocks existed in the south sub-sag are widely distributed and will be a bright prospect for the future petroleum exploration.