珠江口盆地储层特征

Characteristics of reservoirs in the Pearl River Mouth Basin

早渐新世晚期(30Ma)南海运动后,珠江口盆地大部分进入浅水陆架区,由陆相环境向海相环境过渡,古近纪末(23.8Ma)白云运动后,随着海平面的不断上升,盆地整体进入海相沉积环境。珠江口盆地经历了不同的构造演化阶段,发育不同类型的储层,储层主要发育在上部的晚渐新世—第四纪海陆交互相及海相沉积中。浅水区储层主要包括三角洲砂体、陆架砂脊、滨岸砂、生物礁及扇三角洲砂体沉积,其中由古珠江大河控制的陆架三角洲—滨岸体系及生物礁是已发现油田最主要的产层;深水区储层主要包括海底扇,陆架边缘三角洲,台缘斜坡扇沉积,其中低位的海底扇砂体和陆架边缘三角洲是深水区最具潜力的勘探目标。

After the 'South Sea movement' in the late of Early Oligocene,most parts of the Pearl River Mouth Basin are shallow-water shelf deposits,transiting from continental environment to marine environment.After 'Baiyun movement' at the end of Paleogene,the basin wholly entered to marine environment as the sea level rose.Different tectonic evolution that the Pearl River Mouth Basin experienced leads to different types of reservoirs,which mainly developed in late Oligocene-Quarternary marine-continental and marine facies.Reservoirs in shallow water include delta deposits,shelf sand ridges,coastal sandstone,bioreefs and fan deltas,of which the shelf delta-coastal system and bioreef deposits have been found as the most important producing layers of the oil fields.Reservoirs in deep water include submarine fans,shelf-margin deltas and platform-margin slope fan.Among these deposits submarine fans in the LST as well as shelf-margin delta are the most potential exploitation objects in the deep water.