低渗透储集层表面活性剂胶束溶液助排机理  

Mechanisms of water block removal by surfactant micellar solutions in low permeability reservoirs

作　　者：李俊键 刘奔 郭成 苏航 于馥玮 马梦琪 王利达 姜汉桥 LI Junjian;LIU Ben;GUO Cheng;SU Hang;YU Fuwei;MA Mengqi;WANG Lida;JIANG Hanqiao(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249)

机构地区：[1]油气资源与探测国家重点实验室(中国石油大学(北京)),北京102249 [2]中国石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2022年第2期348-357,共10页Petroleum Exploration and Development

基　　金：国家科技重大专项(2017ZX05009-005-003);中国石油大学(北京)科研基金(2462019QNXZ04)。

摘　　要：鉴于针对表面活性剂胶束溶液的研究仍以配方优化和岩心实验为主,且适用于低渗透储集层的助排剂类型及其助排机理尚不明确的现状,在通过岩心实验评价不同类型表面活性剂胶束溶液助排效率的基础上,研制了表征低渗透储集层孔喉结构的多级孔喉系统微观模型,分别开展了盐水及不同盐度表面活性剂胶束溶液在微观模型中的返排实验,直观呈现了表面活性剂胶束溶液作用下微米级孔隙中原油返排的过程,揭示了表面活性剂胶束溶液的助排机理。研究表明,盐水和低盐度表面活性剂胶束溶液驱替及返排过程中均会产生大量小液滴,小液滴通过孔喉时因贾敏效应产生巨大的渗流阻力,导致驱替、返排压差的升高和驱油、返排效率的降低;能够与原油混溶形成WinsorⅢ型微乳液的临界盐度和最佳盐度表面活性剂胶束溶液则不会产生大量阻碍流动的小液滴,能够有效降低渗流阻力,提高驱油及返排效率。The existing researches on surfactant micellar solutions mainly focus on the formulation optimization and core flooding test,and the types and mechanisms of cleanup additives suitable for low permeability reservoir remain unclear.The flowback efficiencies of different types of surfactant micellar solutions were evaluated by core experiments,a multi-level pore-throat system micromodel characterizing pore-throat structures of low permeability reservoir was made,and flooding and flowback experiments of brine and surfactant micellar solutions of different salinities were conducted with the micromodel to show the oil flowback process in micron pores under the effect of surfactant micellar solution visually and reveal the mechanisms of enhancing displacement and flowback efficiency of surfactant micellar solution.During the displacement and flowback of brine and low salinity surfactant micellar solution,many small droplets were produced,when the small droplets passed through pore-throats,huge percolation resistance was created due to Jamin’s effect,leading to the rise of displacement and flowback pressure differences and the drop of flowback efficiency.The surfactant micellar solutions with critical salinity and optimal salinity that were miscible with crude oil to form WinsorⅢmicro-emulsion didnot produce mass small droplets,so they could effectively reduce percolation resistance and enhance oil displacement and flowback efficiency.

关 键 词：低渗透储集层 助排剂 助排机理 表面活性剂 微观可视化实验 原油返排 

分 类 号：TE355[石油与天然气工程—油气田开发工程]