地震地层学在沅江凹陷的应用

APPLICATION OF SEISMIC STRATIGRAPHY TO YANGJIANG DEPRESSION

杨爱棠

Yang Aitang

地质矿产部中南石油地质局

Central-South China Bureau of Petroleum Geology, Ministry of Geology anc Mineral Resources

本文利用地震磁带记录,结合其他物探、钻井地质成果,用地震地层学方法对沅江凹陷第三—白垩纪地层作波组特征的划分,追踪其不整一的接触关系;研究反射能量、结构形态特征与岩性、物性资料相结合,可定性地探讨其地震相与沉积相;据波组反射形态及内部结构,对比其纵横向变化,确定各种构造形态及凹陷内的构造发育特征,从而阐明区域构造发育史,在以上研究基础上,据强反射结构、振幅异常等试定性地预测少数油气圈闭。

In this paper, seismic stratigraphy is applied to interpret the sequences, structural characteristics and depositional facies in Yangjiang District, and the oil/gas prospects are evaluated as well. Ⅰ. Based on the seismic stratigraphic analysis, the Meso-Cenozoic sequences in the depression can be divided by two erosional hiatus, two truncations, three onlaps and a toplap unconformity. Ⅱ. According to the configurations and patterns of the seismic reflections, it is revealed that some growth normal faults developed in the depression. with rolling anticlines and antithetic normal faults during Meso-Cenozoic times there Then, the depression was transformed into a "V" shaped extensional basin by the successive tractions. Ⅲ. Nine types of seismic facies units are classified and the depositional facies belt are established based on the integrated analysis of seismic reflection configurations, structures, and reflective amplitudes combined with other informations. Ⅳ. According to the distribution of strong phase amplitude anomalies ("facies surface"), the possible oil-gas prospects are predicted without the analysis of seismic velocity and frequency.

https://doi.org/10.11781/sysydz198703228