关键词: 油层污染, 微粒堵塞, 侵入深度, 随机过程

Abstract: A mathematical model,which is about a partial differential equation mixture problem,for the contamination of formation due to solid particle invasion,has been put forward by applying stochastic process theory.The function relationship between contamination degree and contamination distance can be obtained by numerical solutions under given time t(the definition of contamination density is also given.).And the permeability K of formation decreases with the increase of contamination degree.The variation of contamination distance with time is finally determined when the permeability K is lowered to a given value K.The calculated results accord with the real case.

Key words: contamination of formation, micrograin stoppage, invasion depth, stochastic process