海上低渗油田注入伴生气驱油最小混相压力实验
Experimental study on the minimum miscibility pressure of associated gas injection for oil recovery in low permeability offshore oil fields
颜祥洲 1郑继龙 1赵军 2吴彬彬2
作者信息
- 1. 湛江南海西部石油勘察设计公司,广东 湛江 524000
- 2. 中海油能源发展股份有限公司工程技术分公司,天津 300452
- 折叠
摘要
为分析L油田注入伴生气驱油能否实现混相驱,开展了最小混相压力测定实验.采用长细管实验法分别测定了海上低渗L油田W31、W32和W51油组含CO2伴生气驱油的最小混相压力,并通过气相色谱仪分析了长细管末端见气前后产出油气组分变化规律.结果表明:气驱前期(0～0.5 PV),注入气未运移至长细管末端,产出流体为原油,不同压力下驱油效率和气油比的变化规律相近;随压力增大,注入气与原油两相相态从非混相到近混相再到混相,气液界面逐渐消失,驱油效率不断增大;在地层压力下,L油田W31和W32油组注入伴生气无法实现混相驱,W51油组注入伴生气可以实现混相驱;伴生气驱油过程中主要萃取原油中的轻烃组分,同时伴生气中CO2和C5+会溶解于原油.
Abstract
To analyze whether mixed phase flooding can be achieved by injecting associated gas in L oilfield,experiments were conducted to determine the minimum miscibility pressure.The minimum miscibility pressure of associated gas flooding in the W31,W32,and W51 oil formations of offshore low-permeability L oilfields was measured using the long and thin tube experimental method,and the variation law of oil and gas compo-nents produced before and after gas breakthrough at the end of the long and thin tube was analyzed using a gas chromatograph.The experimental results showed that in the early stage of gas flooding(0-0.5 PV),the inject-ed gas did not migrate to the end of the long and thin pipe,and the produced fluid was crude oil.The oil dis-placement efficiency and gas oil ratio change law were similar under different pressures.As the pressure in-creased,the phase state of the injected gas and crude oil changed from immiscible to nearly immiscible,and then to mixed.The gas-liquid interface gradually disappeared,and the oil displacement efficiency continued to increase.Under formation pressure,the injection of associated gas into the W31 and W32 oil formations in L oilfield couldn't achieve miscible displacement,while the injection of associated gas into W51 could achieve miscible displacement.During the process of associated gas flooding,the main components of light hydrocar-bons in crude oil were extracted,while CO2 and C5+in associated gas dissolved in the crude oil.
关键词
海上低渗油田/CO2驱/混相驱/最小混相压力/油气组分/伴生气Key words
offshore low-permeability oil fields/CO2 flooding/miscible flooding/minimum miscibility pres-sure/oil and gas components/associated gas引用本文复制引用
出版年
2024
NETL
NSTL
万方数据