Study On Oil And Water Flow Law Of Thick Layer Reservoirs In Group P

The geological feature of the thick reservoir of Group P in BN oilfield is the fault-nose structure,which is mainly controlled by lithology and has good reservoir properties.It belongs to mesoporous-medium-high permeability reservoir;the thickness of single layer is large,the average effective thickness is 114.3m,but the lateral change is fast.The oil well section is long and has an inclination of about 15° to 20°.The BN oilfield is put into development by natural energy mining.In the process of development,there are problems such as low level of formation pressure and rapid decline in production.Currently,large-scale water injection is needed to develop and supplement energy.During the development of water injection,the oil-water movement in the thick oil layer is complicated.Therefore,it is necessary to study and find out the oil-water movement law of thick oil layers under the influence of different factors.Relevant researches believe that the important factors affecting the oil-water movement law of thick oil layers include oil layer thickness,injection-production ratio,formation dip angle and oil layer rhythm.In order to evaluate the effect of these factors on the water flooding of thick oil layers,this paper takes the P-group thick reservoir as the research object,starting from the aspects of oil layer thickness,stratigraphic dip angle and oil layer rhythm,using numerical simulation technology and physical simulation experiment to explore various factors.Under the thick oil layer oil and water movement law.Firstly,the indoor 3D physics simulation experiment was carried out,and the law of oil and water movement in thick oil layers was visually analyzed by experiments.According to the reservoir geological characteristics of the thick reservoirs in Group P,a three-dimensional physical model was made using the relevant similarity criteria.A total of 8 groups of water-flooding physics experiments were carried out.The oil-water movement laws of water-driven oils under different dip angles were studied,and the recovery models of different rhythm models under the same dip angle and the same model were further analyzed.Recovery at different dip angles.Secondly,according to the reservoir geological characteristics of the thick oil layer of the P group,a numerical simulation mechanism model of the injection and acquisition is established by numerical simulation of the reservoir.Due to the limitations of physical simulation experiments,it is impossible to design and manufacture physical models for various influencing factors.Therefore,single-factor analysis can only be carried out using numerical experiments using mechanism models.This paper mainly analyzes the oil-water movement law under the influence of oil layer thickness,injection-production ratio,formation dip angle and oil layer rhythm.At the same time,due to the certain correlation of these factors,these influencing factors are comprehensively analyzed and ranked by orthogonal analysis.The results show that the injection-production ratio,oil recovery rate,horizontal permeability,dip angle and reservoir thickness have a great influence on the development effect of P group thick oil layer water injection.