珠江口盆地高束缚水饱和度成因低阻油层地质控制因素及分布规律差异

摘要

为了更深入地总结珠江口盆地高束缚水饱和度成因的低阻油层的分布规律,以该地区A油田和B油田的低阻油层为例,对其地质控制因素进行了分析.结果表明这2个油田的高束缚水饱和度低阻油层的地质控制因素存在差异,而且控制因素的差异决定了低阻油层平面分布规律的不同,即A油田受陆棚、下临滨砂坝沉积微相代表的低能沉积环境控制,其低阻油层平面分布广泛且和沉积相带分布有较好的一致性;B油田受长石的粒内溶蚀、自生粘土矿物和硬石膏胶结等有利于束缚水形成的成岩作用控制,其低阻油层局部发育且和沉积相带分布规律不一致.本文研究成果对珠江口盆地同类成因的低阻油层的勘探和开发评价具有一定的指导意义.%To further generalize the distribution pattern of low-resistivity oil layer(LROL)caused by high irre-ducible water saturation in Pearl River Mouth basin,the geological factors are analyzed by taking A & B oil-fields as examples.Results show that geological controlling factors is different for these two oil fields,which results in distribution pattern difference of LORL.For A oil field,low energy sedimentary environment repre-sented by such micro sedimentary facies as continental shelf and low shore face sand bar are the geological con-trolling factors and LORL plane distribution is wide and consistent with sedimentary facies distribution.How-ever,in B oilfield,the diagenetic effect contributing to irreducible water such as feldspar grain dissolution and cementation of anhydrite and authigenic minerals is the geological controlling factors and LORL plane distribu-tion is local and different from sedimentary facies distribution pattern.The results can provide reference on ex-ploration and development evaluation of LORL with the similar cause in Pearl River Mouth basin.