沉积残留物的识别及规模

The identification and scale of depositional remnant

在低可容纳空间和浅海大陆架环境中,可容纳空间变化可能导致沉积残留物变化,变化的规模从岩性单一储层规模(几到几十km2)到岩性比较复杂的盆地规模(数百km2)。包裹在低渗透相中的沉积残留物的孔隙、渗透相,是一种比较重要且相对常见的地层圈闭类型。在前陆盆地,沉积残留物更常见于末端而非近端;在斜坡边缘环境,沉积残留物表现出低位体系域与海侵体系域沉积的紧密联系。沉积残留物的识别,可以通过识别广泛分布的区域侵蚀面,以及详细对比上覆和下伏时间地层单位来实现。沉积残留物的识别也是油气勘探和生产很重要的方面,有利于在含油气盆地开发中晚期发现新的勘探区带。

In low accommodation and shallow-shelf settings,spatial variations in accommodation commonly result in the formation of remnants ranging in size from small（few to tens of square kilometers） to basin scale（hundreds of square kilometers）.Remnants of porous and permeable facies encased in low-permeability facies are an important and relatively common type of stratigraphic trap.In foreland basins,remnants may be more common in distal than proximal settings;in ramp-margin settings,depositional remnants appear to be closely associated with lowstand to transgressive systems tract deposits.To identify depositional remnants,the first step is the identification of regionally extensive erosion surfaces;then,the key to remnant identification lies in the detailed correlation of both overlying and underlying time-stratigraphic units.Depositional remnants are used to illustrate their significance to petroleum exploration and production;recognition and integration of the depositional remnant concept into stratigraphic studies may lead to new exploration plays in mature hydrocarbon producing basins.