分子动力学在聚合物驱油中的应用研究进展

Advance in application of molecular dynamics simulation in polymer flooding

传统上,实验室测试和测量被认为是最可靠的表征方法,然而在许多情况下,由于对储层性质范围的敏感性和非均质储层性质的局部变化认识不清,以及基于过于简化的假设条件,使得这种确定性策略获得的特征预测具有高度的不确定性。近年来,分子动力学(MD)模拟在储层岩石、流体性质及其相互作用和原子水平上的研究得到了广泛的关注。在MD中,通过对系统中所有原子运动的牛顿方程的数值解,从原子位置和速度的时间演化分析中提取出有趣的性质。这项技术有助于进行计算机实验,以及进行可能无法完成的、成本极高的或者非常危险的实验。综述了MD模拟技术及其在驱油机理和驱油剂性质研究中的应用,阐述了MD的理论概念和程序,特别是在聚合物驱分析中。这将提供有用的指导方针,以表征储层岩石和流体及其在各种油藏中的行为,有助于更好地优化设计生产计划的运行,为油田聚驱技术的发展提供了理论基础。

Traditionally,laboratory testing and measurement are considered to be the most reliable characterization methods.However,in many cases,due to the unclear understanding of the sensitivity to the range of reservoir properties and local changes of heterogeneous reservoir properties,and based on the oversimplified assumptions,the feature prediction obtained by this deterministic strategy is highly uncertain.In recent years,molecular dynamics(MD)simulation has received extensive attention in the study of reservoir rock,fluid properties and their interactions,as well as at the atomic level.In MD simulation,interesting properties are extracted from the time evolution analysis of atomic position and velocity through the numerical solution of Newton's equations for all atomic motions in the system.This technology can help to carry out the computer experiments which can be used to do the experiments that may not be able to complete,with high cost or very dangerous.In this paper,we review the MD simulation technology and its application in the study of oil displacement mechanism and properties of oil displacement agent,and expounds the theoretical concept and program of MD,especially in the analysis of polymer flooding.It will provide useful guidelines to characterize reservoir rocks and fluids and their behaviors in various reservoirs,help to better optimize the operation of design and production plan,and provide a theoretical basis for the development of polymer flooding technology in oilfields.