强制性海退沉积物与油气分布

强制性海退形成于相对海平面下降期间,对应于早期低位体系域的快速下降和缓慢下降以及晚期高位体系域的缓慢下降,引起沉积环境向海方向的迁移;当沉积物供应充足时,在斜坡边缘地区可以发育典型的进积斜坡沉积,表现在地震剖面中常为前积斜交反射结构。随滨岸线向海退却,在近岸一侧或浅海环境通常缺失低位体系域或陆架边缘体系域,强制性海退形成的砂体沉积往往离岸较远;缓慢下降期的晚期高位体系域也是强制海退的产物。强制性海退可以形成准层序边界和层序边界相一致的特殊现象,层序边界可以构成准层序边界的底界、顶界。

Forced Regressive Sedimentary and the Distribution of Oil and Gas

Forced regressive formats in the decline of relative sea level,corresponding to the early Lowstand systems tract and the late Highstand systems tract,causes the direction of sedimentary environment migrate to the sea.When the sediment supply is sufficient,the slope of the marginal areas can develop into typical plot slope sediments,in seismic common Progressive curved reflection structure.In the lowest position of the sequence is LST,with the coast shoreline retreat to the sea,in shallow coastal environments are often missing Lowstand systems tract or Shelf margin systems tract,Forced regressive sandstone is often far from offshore.Slow decline of the late Highstand systems tract is also a product of forced regression.