摘要
为探讨低渗透油藏注水开发过程中油水互驱微观特征,以柴达木盆地H区路乐河组油藏为例,利用薄片观察、扫描电镜、物性分析及压汞实验等,开展油水互驱微观实验模拟综合研究。研究表明:该区储层物性较差,非均质性较强,岩石类型主要为岩屑长石砂岩和长石砂岩,储集空间以原生粒间孔隙为主,孔喉具有分布宽、分选较差、分布类型多且分散等特征。单相流体实验中原油在岩石内流动具有非达西渗流特征,启动压力梯度随渗透率的增加而降低,但相关性较差,增加压力梯度可使单相油渗流特征达到线性流。油驱水过程为非均匀驱替过程,油藏的微观非均质性强烈,原始含油饱和度较低;水驱油沿一两个通道快速突进,无水采油期短,水驱油效率低,增加压力可实现一定范围内增加水驱油效率,但效果并不明显;残余油主要有绕流形成的残余油、油膜残余油、边缘角隅的残余油等三种,其各自具有不同的形成机理。
The microscopic characteristics of oil-water mutual driving in the process of water flooding development of the low permeability reservoir are really complex.Taking the Lulehe formation reservoir in the H area of the Qaidam basin as an example,based on the thin slice observation,scanning electron microscope(SEM),physical property analysis and mercury pressure test,the oil-water mutual driving microscopic characteristics are comprehensive studied.It shows that the reservoirs are mainly composed of lithic arkose sandstones and arkoses with poor property and strong heterogeneity.Reservoir space is dominated by primary intergranular pores that are characterized by wide distribution,poor sorting,multiple distribution types and dispersal.In the reservoir,the flow of crude oil is non-darcy seepage,and the start-up pressure gradient is reduced along with the increase of the permeability,but the correlation is poor.Linear flow of single-phase seepage occurres after increasing the pressure gradient.It is the non-uniform displacement process with strong heterogeneity and low original oil saturation.Water flooding breakthrough rapidly along one or two channels,water-free oil production period is short,the efficiency is low.The water displacement efficiency can increase by the pressure,but the effect is not obvious.The residual oil types are flow around oil,oil film and the residual oil at the edge of the corner,the formation mechanism is different.
作者
王宝
唐启银
张虎
童金环
李强
李昀龙
李积学
WANG Bao;TANG Qiyin;ZHANG Hu;TONG Jinhuan;LI Qiang;LI Yunlong;LI Jixue(No.2 Oil Recovery Plant,Qinghai Oilfield Company,Haixi 817500,China;Testing Company,Qinghai Oilfield Company,Haixi 817500,China)
出处
《中国矿业》
北大核心
2020年第8期172-177,共6页
China Mining Magazine
关键词
油水互驱
微观实验
残余油
非均质性
柴达木盆地
oil-water mutual driving
microscopic experiment
residual oil
heterogeneity
Qaidam basin
