特低渗储层孔隙结构对CO_2驱特征影响  

The Effect of Pore Structure on CO_2 Flooding Performance in Ultra-low Permeability Reservoir

作　　者：赵清民 吕成远[1] 孙侃[2] 伦增珉[1] 郎东江[1] 

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083 [2]中国石油塔里木油田勘探开发研究院,库尔勒841000

出　　处：《科学技术与工程》2013年第32期9498-9501,共4页Science Technology and Engineering

基　　金：国家863计划(2009AA06ZX1483630)资助

摘　　要：由于强烈的成岩作用,特低渗储层孔隙结构特征复杂。核磁共振实验结果表明,渗透率相近的岩心具有不同的孔隙结构。实验特低渗岩心孔隙结构特征表现为双峰分散型、双峰偏细歪度型及双峰偏粗歪度型。通过核磁共振方法研究了孔隙结构对水驱及后续CO2驱特征的影响。结果表明,不同孔隙结构岩心CO2驱提高采收率机理不同。对于双峰偏细歪度型岩心,CO2驱主要驱替小孔隙中的富集原油,提高了微观波及效率;对于双峰偏粗歪度岩心,CO2驱主要驱替大、中孔隙中的残余油滴和油膜,提高了驱油效率。实验结果为CO2驱提高采收率机理研究及油藏优选提供了参考。The strong diagenesis causes a complicated pore structure characteristic in ultra-low permeability res- ervoir. The experimental results of nuclear magnetic resonance show that cores with similar permeability have differ- ent pore structures, the pore structure characteristic of ultra-low permeability core show double peak dispersion, double peak with smaller slanting degree and double peak with bigger slanting degree. The effects of pore structure on water flooding and CO2 flooding performances were investigated through the method of nuclear magnetic reso- nance. The results indicate that the enhanced oil recovery mechanisms of CO2 flooding in natural cores with differ- ent pore structure are different, for core with type of double peak with smaller slanting degree, the enrichment oil in small pore are mainly displaced, and the microscopic swept efficiency is improved. In contrast, for core with type of double peak with bigger slanting degree, the residual oil and oil film in big and medium pore are displaced, and oil displacement efficiency is increased. The experiments provide references for the study on the recovery mecha- nism of CO2 flooding and the optimization of reservoir.

关 键 词：特低渗油藏 孔隙结构 核磁共振 CO2驱 提高采收率 

分 类 号：TE348[石油与天然气工程—油气田开发工程]