摘要
为兼顾生产成本与开发效果,海上稠油油田开发大多采用多层合采,层内和层间的差异对水驱开发效果影响显著,针对纵向非均质严重的问题,基于不同渗透率级差、不同平均渗透率,建立了反韵律下9种非均质物理模型,研究层内和层间非均质性对海上稠油油田水驱开发效果的影响.研究结果表明:对于层内非均质模型,渗透率级差对开发效果影响更大,平均渗透率相近时,级差越大,层内非均质性越强,注入水沿高渗透层突进,油层下部驱替效果越差,采出程度越低;层内均质层间非均质时,级差越大采出程度越低,高渗层段注入水形成优势通道抑制低渗透层吸水,高渗透层最高采收率达77.4%,低渗层采收率可低至0.7%,使油层上下部驱替效果相差较大;层内和层间都非均质时,分层开采的开发效果好于多层合采,各层采收率变化幅度与分层开采时差异较大;利用综合影响因子表征层内和层间非均质性的综合影响,其值为0.08时对应采出程度为41.48%,综合影响因子越高,纵向非均质性越强,采出程度越低.
In order to consider both production cost and development effect,the multilayer commingled production was common in offshore heavy oilfield,in-layer difference and interlayer difference affect water flooding development effect obviously,concerning this issue the severe heterogeneous,nine reverse rhythm heterogeneous physical models of different permeability ratio and different average permeability were built,the influence in-layer heterogeneity and interlayer heterogeneity on the water flooding development effect in offshore heavy oilfield was studied.The results showed that for the in-layer heterogeneity model,the effect of permeability ratio was observably,if average permeabilities were similar,the greater the permeability ratio,the more intense the in-layer heterogeneity,injected water would break along high permeability layer,the displacement effect of lower formation was bad,recovery degree was low;for the in-layer homogeneity- interlayer heterogeneity model,the greater the permeability ratio,the lower the recovery degree,injected water from high permeability layer would restrain low permeability layer absorption due to preponderance flow path,the highest recovery efficiency of high permeability layer can reach to 77.4%,the lowest recovery efficiency of low permeability layer can reach to 0.7%,which made the displacement effects difference of upper part and lower part great;for the in-layer heterogeneity- interlayer heterogeneity model,the effect of slice mining was better than commingling production,there were recovery efficiency variation amplitude differences of every layer between slice mining and commingling production,the comprehensive influence factor could express the comprehensive influence both in-layer heterogeneity and interlayer heterogeneity,if the comprehensive influence factor was0.08,the recovery degree was 41.48%,so the higher the comprehensive influence factor,the stronger the heterogeneity,the lower the recovery degree.
出处
《数学的实践与认识》
北大核心
2017年第1期128-134,共7页
Mathematics in Practice and Theory
基金
国家重大专项子课题(2011ZX05024-002)
关键词
海上稠油油田
非均质性
渗透率级差
开发效果
offshore heavy oilfield
heterogeneity
permeability ratio
development effect
