基于地震正演模拟的精细层序格架分析 ——以渤海湾盆地梁家楼地区Es3z为例

Refined sequence framework analysis based on seismic forward modeling: a case study of Es3z of Liangjialou area, Bohai Bay Basin

杨丽玉 徐少华 秦磊 毛金昕 李小刚 尚文亮 刘家恺

重庆科技学院复杂油气田勘探开发重庆市重点实验室，重庆 401331 重庆科技学院石油与天然气工程学院，重庆 401331

Chongqing Key Laboratory of Complex Oil and Gas Field Exploration and Development, Chongqing University of Science and Technology, Chongqing 401331, China College of Petroleum and Natural Gas Engineering, Chongqing University of Science and Technology, Chongqing 401331, China

文中利用地震正演模拟技术，基于地震反射结构特征对梁家楼地区Es3z（S6层序）的层序边界进行识别，探索Es3z内部低位体系域（LST）在地震剖面上能够识别的地层厚度下限，建立Es3z时期的精细层序格架。研究发现：当地震主频为22 Hz时，梁家楼地区LST在地震剖面上可识别的沉积厚度下限为45 m。由下至上准层序S6-7至S6-6属于高位体系域（HST），准层序S6-5至S6-2属于下降体系域（FSST），准层序S6-1是LST（低位体系域）和TST（海侵体系域）的复合体系域。受气候影响，季节性湖盆可容空间的快速变化导致梁家楼地区LST沉积厚度往往较薄。

Using seismic forward modeling technique, and based on seismic reflection structure characteristics, this paper identified sequence boundaries of Liangjialou area Es3z (S6 sequence), and explored the lower limiting value of identifiable formation thickness of the lowstand systems tract (LST) of Es3z on the seismic section. The fine sequence framework of Liangjialou area in Es3z period was established. The study shows the lower limiting value of identifiable sedimentary thickness of LST on the seismic section in Liangjialou area is 45 m when seismological dominant frequency is 22 Hz. From bottom to top, parasequences S6-7 to S6-6 belong to the highstand systems tract (HST), parasequences S6-5 to S6-2 belong to the falling stage systems tract (FSST), and parasequence S6-1 is a complex system tract of the lowstand systems tract (LST) and the transgressive systems tract (TST). Influenced by the climate, the thickness of LST in Liangjialou area is usually thin due to the rapid change of the accommodation in the seasonal lake basin.

10.6056/dkyqt202101015