An improved LB pseudo-potential multi-relaxation multiphase model is used to study flow characteristics of single/dual droplets impacting liquid film. Development of liquid film impacted by a single droplet under different gas-liquid density ratio was investigated. It was found that with decrease of density ratio, top of coronal crown started bending inward, and bottom radius is significantly reduced. Then, double droplets impinging on liquid film was studied with large density ratio. It shows that a central jet was generated as double droplets impacting on liquid film. Increase of horizontal spacing between droplets delaied the appearance of central jet and reduced height of the initial central jet. With the increase of Re, height of the central jet increased obviously.

A complete analytical method for coefficient of charge on plane elements in SCM(surface charge method) is complicated under linear or high order charge density approximation.A kind of semi-analytical integration is proposed.It transforms the integral under local reference into a separable double integration under global reference.Since the inner layer integration is analytical,the original integration can be simplified to a one-dimensional problem which can be calculated by traditional numerical method.As for singular integral,eliminating singularity technique by adding auxiliary function is adopted.It indicates that high precision is achieved and the method is applicable.

A muhi-component mathematical model characterizing polymer enhanced foam flooding filtration is established with mass conservation principle of foam components. Considering combination of foam generation, coalescence and migration phenomena, the model effectively reflects mechanism of oil phase foam coalescence and polymer foam stabilizing. Differential numerical solution is conducted with adaptive implicit method. Validity of the mathematical model is verified with experiment. Meanwhile, taken foam flooding pilot region of a oilfield, a numerical simulator is employed to study filtration characteristics of enhanced foam flooding. It is indicated that the foam system could exist stably in the formation and gradually advance to production wells to improve oil recovery.

By using explicit saturation and implicit concentration methods,numerical solution is presented to the polymer drive model characterizing dispersion and adsorption of polymer solution flowing through a porous medium.Saturation equation is solved by using an explicit total variation diminishing(TVD)method.To ensure the stability of concentration equation calculation,Crank-Nicolson difference format is used in spatial discretization,and variable is quasi-linear disposed in temporal discretization.The validity of the method presented is verified by comparison with analytic solutions.The calculated example indicates that dispersion causes dilution and dissipation of polymer solutions,and adsorption results in a loss,thus leading to lagging of concentration propagation.Also,the important polymer flooding mechanism- "oil block" is illustrated in the results of calculation.Under the condition of slug injection,the breakthrough time of oil enrichment zone lies between the breakthrough time of polymer concentration front and polymer concentration peak.