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.