迈陈凹陷三角洲地层地震沉积学解释

Seismic Sedimentology Interpretation of Delta Strata in Maichen Depression

以迈陈凹陷古近系流三段三角洲地层为例,探索适合滚动勘探阶段井震结合的地震沉积学研究方法。流三段为湖泊三角洲沉积环境,发育三角洲前缘水下分流河道、水下分流河口砂坝、席状砂等沉积微相类型。根据研究区单砂体厚度小、平面差异大的特点,构造新的地震属性类型,通过多属性优选和井点标定的属性定量分析预测砂岩分布,建立平面沉积微相的初步认识。利用相位转换剖面和地震相分析落实相边界位置,实现沉积微相的精细描述。该方法对其他地区滚动勘探阶段的沉积微相研究具有指导意义。

Taking Paleogene delta strata of Liusan Formation in Maichen Depression as an example, this paper probes into seismic sedimentology study method suitable for progressive exploration stage. The sedimentary environment of the study strata is lacustrine delta with underwater distributary channel, distributary channel mouth bar, sand sheet and so on. A new seismic attribute is created due to the thin and lateral-instahle sand bodies, and sand distribution is predicted with multi-attributes selection and well-calculated quantitative seismic attributes analysis, and thus a preliminary understanding of the microfacies distribution is achieved. Then phase-rotating seismic profiles and classical seismic facies analysis are employed to get fine sedimentary facies distribution. This study builds a practical seismic sedimentology study method and workflow which can be used in microfacies study of progressive exoloration stage in other oil fields.