注空气提高低渗透油藏采收率实验及低温氧化反应特征  

EOR experiment of air injection and low-temperature oxidation reaction characteristics in low-permeability reservoirs

作　　者：钱川川[1] 骆飞飞[1] 蒋志斌[1] 祁丽莎[1] 冯利娟[1] QIAN Chuanchuan;LUO Feifei;JIANG Zhibin;QI Lisha;FENG Lijuan(PetroChina Xinjiang Oilfield Company,Karamay 834000,China)

机构地区：[1]中国石油新疆油田公司,新疆克拉玛依834000

出　　处：《大庆石油地质与开发》2022年第1期97-103,共7页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家科技重大专项“新疆低渗砂砾岩油藏CO_(2)驱油与埋存关键技术研究”(2016ZX05016-004)。

摘　　要：空气驱是一种有效提高低渗透油藏采收率的方法。针对目前空气驱油生产特征不明确的问题,采用长岩心驱替实验,研究不同注入压力下的空气驱油效果和低温氧化反应特征。研究发现,空气驱油存在明显的“气窜拐点”。气窜发生前,采出程度随注气量的增加迅速增加,一旦发生气窜,采出程度的增加明显放缓。注气压力越高,“气窜拐点”出现越早,提高采收率效果越差。原油组分分析结果表明:在油藏温度下,随着注气量增加,产出原油中的轻质组分减少,重质组分增加,驱替过程中发生了低温氧化反应;注入压力越高,低温氧化反应越充分,采收率越高;对高含水油藏进行空气驱,低温氧化反应十分微弱,无法形成烟道气驱;水驱达到经济极限后转空气驱,采收率可提高近10百分点。研究成果为低渗透油藏开发后期注空气提高采收率提供了理论依据。Air injection is an effective way to enhance oil recovery of low-permeability reservoirs.In the light of current unclear production characteristics of air injection displacement,with the help of long-core displacment experiment,the air displaced effects and low-temperature oxidation reaction characteristics under different injection pressures are studied.The studies show that there is an obvious“inflection point of gas channeling”in the air injection displacement.Before the gas channeling,the recovery degree rises quickly with the increase of injected air volume,and the increase lowers down remarkably once gas channeling occurs.The higher the air injection pressure is,the earlier the“inflection point of gas channeling”appears,and the EOR effect becomes poor.Analyses of crude oil components show that the low-temperature oxidization reaction occurs during the displacement with the increase of air injection volume,decrease of light components in produced oil and the increase of heavy components at reservoir temperature.The higher the air injection pressure is,the more complete the low-temperature oxidization reaction is and the higher the oil recovery is.When air injection is operated in high-watercut oil reservoirs,the low-temperature oxidization reaction is weak and cannot realize flue gas displacement.When water-drive reaches its economic limit,it is converted to air injection displacement,and the recovery can be enhanced nearly 10%.The research achievements provide theoretical evidences for EOR by air injection in the late development of low-permeability reservoirs.

关 键 词：低渗透油藏 空气驱 低温氧化反应 提高采收率 物理实验 

分 类 号：TE357[石油与天然气工程—油气田开发工程]