摘要
南海西部油田高泥质疏松砂岩储层众多,大部分岩样无法直接利用压汞法测量其微观孔隙结构,常规驱替实验易出现岩心浆化现象而失败。选取南海西部目标油藏不同渗透率级别下的4块典型岩样,通过显微CT扫描建立数字岩心,获取介质孔道的三维几何构型及孔径尺寸的分布特征,再利用微观孔道网络模拟方法得到了储层岩石的物性参数及其非线性渗流特征,并从微观孔道网络的角度分析了储量动用过程。相同压力梯度下,渗透率越低的岩心,参与流动的孔道段数比例越小;孔径较大的孔道数量少,但其总体积与中等孔径相差不大。对于储量动用程度,压力梯度较小时,大孔道对储量动用贡献率较大,随着压力梯度增大,中小孔道贡献率增加,此时参与流动孔道中的最小孔径较小。
The micro-pore structures for rock samples in western South China Sea cannot be directly measured by the mercury intrusion method because of high mud content in loose sandstone reservoirs, and the regular flooding experiments always fail as the core slurring appears. Digital cores established through micro-CT for 4 selected typical rock samples from the target reservoir of western South China Sea under different permeability conditions and their 3D geometrical configurations of tunnels and distribution characteristic of pore size were obtained. The micro-pore-network simulation was used to study physical parameters of reservoir rocks and nonlinear flow characteristics, and reserve producing process was analyzed from micro-pore-network view- point. Under the same pressure gradient, the lower the core permeability is, the less the tunnels participate in flow are. Though the number of larger tunnels is low, the total volume difference between large tunnels and mid-pore is small. The reserve producing contribution of large tunnels is high under a small pressure gradient. The reserve producing contribution of medium and small tunnels increases and the minimum pore size participating in flow decreases with the increasing of pressure gradient.
出处
《中国海上油气》
CAS
CSCD
北大核心
2015年第4期86-92,共7页
China Offshore Oil and Gas
基金
中海石油(中国)有限公司综合科研项目"文昌13-2油田微观渗流机理及影响因素研究(编号:ZYKY-2014-ZJ-03)"部分研究成果
关键词
南海西部油田
高泥质疏松砂岩
数字岩心
微观孔道网络模拟
非线性渗流特征
储量动用过程
oilfields in western South China Sea
loose sandstone with high mud content
digital core
micropore-network simulation
nonlinear flow characteristie
reserve producing process
