致密油藏混合润湿对孔隙尺度渗吸的影响  

Effect of mixed wettability of tight reservoirs on the pore scale imbibition law

作　　者：濮御 杨二龙[1] 杜庆龙[3] PU Yu;YANG Erlong;DU Qinglong(Key Laboratory of Improving Oil and Gas Recovery,Ministry of Education,Northeast Petroleum University,Daqing,Heilongjiang 163318,China;School of Civil Engineering,Northeast Petroleum University,Daqing,Heilongjiang 163318,China;Exploration and Development Research Institute,PetroChina Daqing Oilfield Company Limited,Daqing,Heilongjiang 163712,China)

机构地区：[1]东北石油大学提高油气采收率教育部重点实验室,黑龙江大庆163318 [2]东北石油大学土木建筑工程学院,黑龙江大庆163318 [3]中国石油大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712

出　　处：《东北石油大学学报》2024年第1期86-95,I0007,共11页Journal of Northeast Petroleum University

基　　金：国家自然科学基金面上项目(52274037);中央支持地方高效改革发展资金人才培养项目(14011202101);黑龙江省博士后科研启动基金项目(LBH-Q21012);海南省科技专项(ZDYF2022SHFZ107)。

摘　　要：以毛细管压力为基础的渗吸作用可有效动用致密储层中的原油并补充能量。为了研究混合润湿程度与渗吸采出程度之间的关系,以及典型混合润湿孔喉通道渗吸规律,基于相场理论和Navier-Stokes方程,建立静态孔隙尺度渗吸数值模型,对孔隙尺度渗吸过程进行数值模拟,分析不同混合润湿程度对渗吸采油效果的影响。结果表明:混合润湿占比为10%的混合润湿岩石孔隙渗吸采出程度比纯水湿的采出程度高。当混合润湿占比低时,混合润湿通道为渗吸的主力通道,渗吸效果与纯水湿的类似;当混合润湿占比超过40%时,渗吸采出程度低于10%,渗吸效果差;当混合润湿占比高时,连通性好且成片存在的水湿孔喉成为混合润湿体系渗吸排驱采油的主要优势通道,连续的油湿孔喉抑制水相流动,导致渗吸作用停止。该结果为阐明混合润湿程度和混合润湿分布的渗吸规律和流动潜力、提高致密油藏的采收率提供指导。The imbibition predicated upon the capillary pressure,can effectively produce the oil and complement the formation energy.In order to explore the relationship between the mixed wetting percentage and the imbibition recovery,as well as the imbibition law in the typical mixed wetting pore-throats,the pore scale imbibition numerical model is established based on phase field theory and Navier-Stokes equation.A series of numerical simulations of pore scale imbibition processes are conducted to analyze of the influence of different mixed wetting degrees on imbibition oil recovery.Results indicate that the imbibition recovery of core with the mixed wetting of 10%is higher than that of pure water-wetting system.For the low mixed wetting percentage,the mixed wetting pore-throats are also the main channel for imbibition oil recovery,whose imbibition effect is the similar as that of the water-wetting channel.When the mixed wetting percentage exceeds 40%,the imbibition recovery is less than 10%,resulting in the poor imbibition effect.For the high mixed wetting percentage,the well-connected and contiguous water-wetting pore-throats become the main advantageous channel for imbibition,while the continuous oil wetting pore-throats hinder the fluid flow,inducing the cessation of the imbibition.The results elucidate the imbibition mechanism and flow potential of mixed wetting degree and mixed wetting distribution,which is of great significance for improving the recovery rate of tight oil reservoirs.

关 键 词：致密油藏 混合润湿 孔隙尺度 毛细管压力 渗吸规律 采出程度 

分 类 号：TE348[石油与天然气工程—油气田开发工程]