Study And Application On Flow Model Of Tight Reservoirs Considering Influences Of Boundary Layer

The throats of tight reservoir are narrow with the size of nanoscale.Many researches have shown that the boundary layer has large proportion when fluid flowing in small throats,which is an important factor of non-linear flow characteristics.The present studies of non-linear flow characteristics are based on macroscopic phenomena.These theories should be learnt from microscale if the mechanism wanted.However,the scale of physical modeling is much larger than the size of throats in tight reservoirs.Another method should be explored to study them.Researches show that the dissipative particle dynamics(DPD)is a feasible method.This paper modifies traditional DPD method to make it conform more to actual interaction,and then builds models of nano-throats and makes the simulation.From the simulation,relationship between boundary layer proportion and factors are studied,the microscale flow mechanism in nano-throats analyzed,expression and change features of boundary layer got,equation of non-linear flow characteristic elicited and effective permeability put forward.Using the equation,the mathematic model of non-linear flow in tight reservoir is built and the influences of non-linear flow on the production of tight reservoirs are studied.In short,this paper gets two goals.The first goal is exploring a new method to study flow in nano-throats and analyzing the charecteristics of it.The other goal is putting forward a new way to express non-linear flow,which quantificats the curve part of the non-linear flow characteristic curve and reveals the essence of non-linear flow.