重力同沉积断层的数值模拟

Numerical Simulation of Gravity Synsedimentary Fault

从动力学角度考虑，同沉积断层有两种成因：一种是构造成因，主要指由基底断裂活动对上覆沉积盖层影响，并在盖层中延伸。这类断层规模大且常常卷入基底，我国东部许多断陷盆地的边缘断裂及一级断裂多属此类。另一种为重力成因，多为中、小型规模，且广泛发育于沉积盖层中。本交通过建设性三角洲沉积体系的一个轴向剖面，建立了二维有限元模型，应用弹性力学方法对后一种成因的同沉积断层形成机制进行模拟，并对其铲状形态及发育方向进行探讨，更重要的是对砂体展布进行预测，直接服务于生产。

According to dynamics analysis,synsedimentary fault has two kinds of origin:one is tectonic origin,mainly refers to that basement fracture movement innuences oversedimentary cover and extents in covers,this kind of fault is great scope and often involuts basement lanother is due to gravity. For the second situation,fault is usually middle or small scope,and develops in sedimentary covers widely. The paper builds a two-dimensional finite-element model based on an axial profile of depositional system of con structive delta,and simulates the forming mechanism of the later by applying elastic mechanics method.Meanwhile, the author discusses its shovel-shape and development direction,particularly, forecasts sandbody spread. Finally,the paper shows that the fault nest sand body controlled by gravity rynsedimentary fault has very high economic value in the hydrocarbon exploration.