地震地层体及其分析方法

Seismic stratigraphic volume and its analysis method

地震地层体是指一种利用地震反射波所蕴含的地层反射界面特征和地层沉积特征,从地震数据中提取的一系列地震层位所组成的特殊三维数据体,是前人所提出的"相对地质年代体"和"层位体"概念的一种扩展。利用地震地层体可确定地层界面的形态及某些层状或近层状地质体的外部轮廓,并可根据不同地层界面之间的接触关系对地质构造和沉积环境进行分析。本文首先介绍地震地层体概念,然后详细描述了地震地层体分析方法及流程,最后以理论模型和实例说明这套方法具有的特点及能生成高精度地震地层体的良好应用效果。基于倾角传播技术的地震地层体分析方法能在地层倾角扫描的基础上获得高精度地震地层体,为真三维构造解释模式提供了一种实现途径。与前人所提出的层位体方法相比,本文提出的地震地层体分析具有三个特点:1利用基于最小方差法多方位倾角估算技术可获得高精度地层倾角信息;2应用倾角传播技术可提高层位追踪的准确性;3在复杂断裂区利用控制层位对追踪层位进行校正。

Seismic stratigraphic volume is a special 3D seismic volume which is composed of a large number of horizons extracted from seismic data based on stratigraphic reflection interface and sedimentation characteristics in seismic reflection waves.The concept ofseismic stratigraphic volume'is an extension ofrelative geologic time volume'andhorizon cube'proposed by predecessors.Seismic stratigraphic volume can be used to unearth the topography of stratigraphic interfaces and extract the shapes of layered or near-layered geobodies,and implement structure and depositional environment analysis according to the contact relationship among different stratigraphic interfaces.First we discuss in this paper the concept of seismic stratigraphic volume,and then introduce a seismic stratigraphic analysis method and its typical workflow in detail.Finally we use a theoretical model and a real example to introduce its characteristics and illustrate its effects in generating high-precision seismic stratigrahic volume.Seismic stratigraphic volume analysis technique based on dip spreading can achieve high-precision seismic stratigraphic volume,and provide an effective way for real 3D structure interpretation mode.Compared with previous horizon cube technique,seismic stratigraphic volume analysis has three characteristics:A.using dip-scanning technique based con minimum variance algorithm to achieve high-precision stratigraphic dip field;B.using dip spreading technique to improve the precision of horizon auto-tracking;C.using control horizons to implement horizon adjustment in complex fault block zones.