海上油田高倍水驱油微观驱油规律试验  

Experiment on micro oil displacement of high volume water flooding in offshore oilfields

作　　者：李彦来 杨东东 刘春艳 王美楠 郭敬民 LI Yanlai;YANG Dongdong;LIU Chunyan;WANG Meinan;GUO Jingmin(Tianjin Branch of CNOOC(China)Company Limited,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《中国石油大学学报(自然科学版)》2025年第2期183-188,共6页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：中国海洋石油集团公司“十四五”重大科技项目(KJGG2021-0501)。

摘　　要：为了进一步明确高倍数水驱油的微观机制和岩心物性的时变规律,以指导海上油田高含水后期开发。采用先进低场核磁共振技术,利用在线原位成像试验实现岩心高倍数水驱过程的可视化;同时,基于水驱过程中的岩心动态核磁T_(2)谱,量化不同孔隙内微观驱油效率,分析不同位置岩心孔隙的变化;最后,基于试验结果建立储层尺度的渗透率时变模型。结果表明:高倍水驱能够大幅度降低残余油饱和度,提高驱油效率,中孔的贡献最大,大孔与小孔的贡献相对较小;高倍水驱会改变有效孔隙分布,沿着水驱方向,靠近注入端的岩心内有效孔隙增多,而靠近出口端的有效孔隙减少;在高倍水驱后岩心的有效孔隙度增大,渗透率也相应增加。It is important to deepen the understanding of the oil displacement mechanisms behind high volume water flooding and the changes of rock physical properties of offshore oilfields with high water cut.In this study,an innovative online in-situ imaging set-up for core flooding was used to conduct micro oil displacement experiments using a low-field nuclear magnetic resonance(NMR)technique.Based on the NMR T_(2)signal analysis,the micro oil displacement efficiency within different pores was quantified,and the changes in pore size distribution during high volume water flooding were examined.A reservoir scale permeability time-varying model was established based on experimental results.The results show that high volume water flooding can significantly reduce residual oil saturation and improve oil displacement efficiency.The contribution from mesopores to oil recovery is the largest,while the contributions from macropores and small pores are relatively small.Moreover,high volume water flooding can lead to changes in pore size distribution,resulting in an increase of the effective pore volume near the injection site and a decrease in pore volume near the outlet of the core along the direction of water flooding.Furthermore,the experimental results show that,after high volume water flooding,the porosity of the core increases and its permeability improves.

关 键 词：高倍水驱 微观机制 核磁共振 驱油效率 物性时变 

分 类 号：TE353[石油与天然气工程—油气田开发工程]