摘要
克拉玛依砾岩油藏目前处于高含水开发阶段,储层精细分类特征研究及不同油藏类型水驱油机理和影响因素分析成为油藏提高采收率的基础和关键.首先利用储层综合对比技术,从沉积物源、岩石学特征、物性特征、渗流特征及孔隙结构等方面分析三类油藏,明确导致不同类型砾岩油藏水驱油机理存在差异的根本原因;然后基于核磁共振岩心分析技术进行微观水驱油机理研究.实验结果表明:水驱过程中大孔隙中的原油采出程度最高,而渗吸过程中主要动用中小孔隙中的原油,水驱方式与渗吸作用的结合可有效提高砾岩油藏采收率.分析三类砾岩油藏储层物性、孔隙结构、微观非均质性、润湿性及原油黏度对水驱油效率的影响,其中物性及微观孔隙结构的不同导致微观水驱油机理的差异,而在宏观上储层的非均质性、润湿性和原油黏度又对注入水的渗流体系和驱替路径起决定作用.综合分析结果表明:Ⅰ类油藏水驱油效率最高,Ⅱ类的次之,Ⅲ类的最差.最后结合测井与生产动态资料,讨论水驱油特征对储层整体水淹规律的控制作用.当储层性质相似时,注水条件越强,水淹程度越高;当注水条件相似时,储层物性越好,水淹越强,另外,相同油藏类型物性较差的Ⅲ、Ⅳ类流动单元储层在非强水洗条件下,一般表现为弱水淹层,甚至为油层,成为剩余油富集的有利区.
The conglomerate reservoir in Karamay oilfield presently is in high water development stage,the research on fine reservoir classification characteristics and analysis on water displacing oil of different reservoir types and their influence factors become the basis and key for improving oil recovery.In this paper,firstly the comprehensive reservoir contrast technique is used to analyze reservoir feature of three types of conglomerate reservoirs from sedimentary source,petrological characteristics,physical property,percolation characteristics and pore structure etc,and make clearly the basic reason of water displacing oil mechanism difference for different types of conglomerate reservoir.Then the micro water displacing oil mechanism is researched based on NMR core analysis technology,the experimental results show that the recovery percent of reserves of large pore is the highest in the water displacing oil process,and in the imbibition process the crude oil in middle-small pores is mainly displaced.So the combination with water displacing method and imbibition way can effectively improve the conglomerate reservoir recovery.Based on above research,the influence factors of water displacing oil efficiency are analyzed for three types of conglomerate reservoir,which include to physical property,pore structure,micro-heterogeneity,wettability and crude oil viscosity etc,in which the difference of physical properties and micro pore structure leads to the difference of micro water displacing oil mechanism,and in macroscopic the reservoir heterogeneity,wettability and crude oil viscosity play a decisive role to seepage system and displacement path of injection water.The comprehensive analysis results show that the water displacing oil efficiency of reservoirⅠis the highest,reservoirⅡis the secondary and reservoirⅢis the worst.Finally,the control action what water displacing oil feature influence whole reservoir water flood rule is discussed combined with well logging data and production performance information.When the reservoir properties are similar,the water flood degree is higher with stronger of water injection conditions,when the water injection conditions are similar,the water flood degree is higher with better of reservoir physical properties.In addition,for the same reservoir type the flow unitⅢ,Ⅳ with poor physical property generally express low water flood layer under non-strong washing conditions,even as the oil layer,these reservoir become the favorable area of remaining oil enrichment.
出处
《东北石油大学学报》
CAS
北大核心
2015年第4期21-30,118,共11页
Journal of Northeast Petroleum University
基金
中国科学院大学校部青年教师科研启动基金项目(55103BY00)
国家基础研究发展计划(973计划)项目(2007CB209600)
关键词
砾岩油藏
储层分类特征
水驱油机理
影响因素
水淹规律
克拉玛依油田
conglomerate reservoir
reservoir classification characteristics
mechanism of water displaced oil
influencing factors
water flooding laws
Karamay oilfield