特低渗油藏CO_2驱扩大波及体积的一种新技术  

A New Technique for Enlarging Sweeping Area for CO_2 Drive in Extra-Low Permeability Reservoirs

作　　者：于春磊[1] 侯吉瑞[1] 赵凤兰[1] 郭彪[1] 

机构地区：[1]中国石油大学石油工程教育部重点实验室提高采收率研究中心,北京昌平102249

出　　处：《油田化学》2009年第2期165-168,共4页Oilfield Chemistry

基　　金：国家973项目"温室气体提高石油采收率的资源化利用及地下埋存"(项目编号2006CB705805)

摘　　要：CO2气驱油藏易出现气窜。乙二胺注入性好,可与CO2反应生成碳酸盐,选择性地封堵CO2气窜通道。本文报道在模拟吉林红岗北油藏条件下(102℃,K<0.01μm2)CO2气驱岩心乙二胺封堵实验结果,注入段塞结构为:0.1PV氮气+0.2PV乙二胺+0.1PV氮气。在气驱水填砂管(长100cm)中,乙二胺注入压力平稳,在0.2kPa以下,封堵后CO2气突破压力高达22MPa,沿程压力降和渗透率表明封堵发生在填砂管中段,封堵后气测渗透率振荡式变化并趋于平稳;并联填砂管封堵后,高渗管渗透率大幅下降(0.0184→0.000165μm2),低渗管渗透率(0.0038×10-3μm2)大体不变,沿程压力变化表明封堵发生在高渗管30～60cm段,乙二胺未进入低渗管;非均质压制人工岩心封堵后,CO2气驱油采收率提高19.8%,其中高渗岩心提高17.1%,低渗岩心提高2.7%。Gas breakthrough often occurs in gaseous CO2 driving oil reservoirs. Ethylenedlamine, EDA, possesses good injectivity, reacts with CO2 to form carbonates and thus creates blockages in gaseous CO2 passages selectively. In this paper the experimental results of plugging gaseous CO2 driving cores by EDA were presented with injected slugs ：0. 1 PV of nitrogen gas ＋ 0. 2 PV of EDA ＋ 0. 1 PV of nitrogen gas. In a sand packed tube（SPT） 100 cm long,saturated with water and drived by CO2 gas,the EDA injecting pressure was steady, 〈 0.2 kPa; a CO2 gas breakthrough pressure as high as 22 MPa was observed for the plugged SPT; the plug was created in the middle zone of SPT as indicated by the pressure drop and gas permeability data along the driving direction;the gas permeability of the plugged SPT changed with driving time oscillatorily and soon became steady. As for the plugged SPTs in paralell, the gas permeability of the high permeable SPTs was dramatically dropped from 0. 0184 to 0. 000165 μm^2 and that of low permeable SPTs kept basically unchanged ,0. 0038 × 10^-3 and 0. 0040 × 10^-3/μm^2 the plug was formed in the middle zone ,30---60 era, of the high permeable SET and no EDA entered into the low permeable SET. Plugging of hetergeneous artificial core by EDA resulted in an enhancement in oil recovery by CO2 gas driving of 19. 8% ,17. 1% ,and 2. 7% for whole core,high and low permeable layers,respectively.

关 键 词：特低渗油藏 二氧化碳气驱 气窜 封(堵气)窜 乙二胺 波及体积 吉林红岗北油田 

分 类 号：TE357.7[石油与天然气工程—油气田开发工程] TE39