西南石油大学学报(自然科学版) ›› 2022, Vol. 44 ›› Issue (5): 105-112.DOI: 10.11885/j.issn.1674-5086.2022.03.09.02

• 石油与天然气工程 • 上一篇    下一篇

离子匹配精细水驱提高采收率机理研究

许世京1,2, 伍家忠2,3, 陈兴隆2,3, 刘庆杰2,3   

  1. 1. 中国石化有限公司综合管理部, 北京 海淀 100020;
    2. 中国石油勘探开发研究院, 北京 海淀 100083;
    3. 提高石油采收率国家重点实验室, 北京 海淀 100083
  • 收稿日期:2022-03-09 发布日期:2022-10-28
  • 通讯作者: 伍家忠,E-mail:wujiazhong@petrochina.com.cn
  • 作者简介:许世京,1986年生,男,汉族,河南南阳人,高级工程师,博士,主要从事油气田开发方面的工作。E-mail:xushijing@sinopec.com;
    伍家忠,1967年生,男,汉族,湖南澧县人,副教授,博士,主要从事注入介质与储层介质相互作用基础研究和功能性水驱技术研究工作。E-mail:wujiazhong@petrochina.com.cn;
    陈兴隆,1974年生,男,汉族,山东济宁人,高级工程师,博士,主要从事油层物理及渗流力学方面的工作。E-mail:chxlhdpu@petrochina.com.cn;
    刘庆杰,1971年生,男,汉族,河北石家庄人,教授,博士,主要从事油田开发及提高采收率方面的工作。E-mail:lqj@petrochina.com.cn
  • 基金资助:
    国家科技重大专项(2017ZX05013-003);国家自然科学基金青年基金(51606222);中国石油天然气股份有限公司“十三五”重大科技项目(2016A-0903)

A Study on Mechanism of EOR by Ion Matching Water Injection

XU Shijing1,2, WU Jiazhong2,3, CHEN Xinglong2,3, LIU Qingjie2,3   

  1. 1. General Administration Department of China Petrochemical Corporation, Haidian, Beijing 100020, China;
    2. Research Institute of Petroleum Exploration & Development, PetroChina, Haidian, Beijing 100083, China;
    3. State Key Laboratory of Enhanced Oil Recovery, Haidian, Beijing 100083, China
  • Received:2022-03-09 Published:2022-10-28

摘要: 水驱是油田开发的主要技术,但常规水驱只是通过向地层补充能量的方式提高采收率,而离子匹配水驱技术则是基于油藏介质中固-液微界面作用强的特点,通过对注入水离子类型和强度的精确离子匹配实现剥离残余油膜提高驱油效率。以西峰油田为例,结合室内驱油实验、Zeta电位测量、原子力显微分析和界面作用力数值计算等方法,系统研究了离子匹配精细水驱技术提高低渗油藏采收率的主控因素。结果表明,随着注入水离子类型的调整和离子浓度的改变,在二次采油和在三次采油模式下,离子匹配精细水驱分别比模拟地层水驱提高采出程度15.6和9.8个百分点。其中,界面的Zeta电位和分离压的大小与离子匹配精细水的离子类型关系密切。相同离子浓度情况下,数值计算与原子力显微分析实验所得结果均表明,Na+比Ca2+和Mg2+的分离压高,从而表现出了更有利于从岩石表面剥离油膜的能力;同时,随着注入水离子浓度的降低,盐水-原油-岩石界面的Zeta电位负值和分离压均呈增大的趋势,油和岩石表面之间的斥力增大,致使残余油更容易从岩石表面剥落,离子匹配精细水驱有助于提高水驱油藏的开发效果。

关键词: 离子匹配精细水驱, 提高采收率, Zeta电位, 原子力显微分析, 分离压

Abstract: Water flooding is the main technology of oilfield development, with conventional mechanism of supplementing energy to the formation. However, ion matching water injection technology enhance the oil recovery through reservoir oil-water-rock interaction. Taking advantage of strong solid-liquid micro interface in the reservoir media, injection with ion matched water could improve oil displacement efficiency by matching the type and strength of ions in injected water with that in reservoir to peel off the residual oil film. Taking Xifeng Oilfield as an example, laboratory core flooding experiment, Zeta-potential measurements, Atomic force microscopy(AFM) force-distance measurement and direct numerical simulation of interfacial force are used to analyze the influencing factors of disjoining pressure as well as Zeta-potential at the oil-brine-rock interfaces, so as to explain the EOR mechanism of ions tuning water(ITW) flooding from microscale. Core flooding experiments show that both in secondary and tertiary modes, ITW can enhance oil recovery by 15.6 and 9.8 percentage point compared with coventional water flooding; Zeta-potential and AFM force-distance measurements show that Zeta-potential and disjoining pressure are influenced by the concentration and ionic type of the brine, which determine the detachment of the residual oil from rock. At the same ion concentration, the results of numerical calculation and atomic force microscopy analysis show that the disjoining pressure of Na+ is higher than that of Ca2+ and Mg2+, which shows the stronger ability to peel oil film from rock surface. Moreover, with the decrease of ion concentration of injected water, the negative value of Zeta-potential and disjoining pressure at the interface of brine-crude oil-rock are increasing, and the repulsion force between oil and rock is increasing, which makes the residual oil easier to peel off from the rock. ITW is helpful to improve the development effect of water flooding reservoir.

Key words: ions tuning waterflooding, EOR, Zeta-potential, atomic force microscopy, disjoining pressure

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