Study Of Macroseepage Flow Law Based On Microseepage Mechanism

The microscopic and macroscopic properties of reservoir are closely related to each other, and microscopic heterogeneity determines macroscopic heterogeneity indirectly. The aim of this passage is to integrate the microscopic characteristics into calculation of macroscopic seepage process, and to show the microscopic seepage mechanism through macroscopic seepage process. And in order to study the seepage in the reservoir further.The research in sedimentology shows that depositional environment and diagenesis affects the reservoir microscopic characters a lot. This thesis takes different depositional microfiches from the upper section of Xiguan from the 7th area of Gudong oilfield as study targets. In this thesis, the similarities of microscopic properties of the reservoir which have same depositional microfiches and the differences between microscopic properties of the reservoir which have different depositional microfiches are studied from the aspect of formation depositional character. The study shows the possibility of dividing the reservoir macroscopically with the considering of depositional microfiches.The reservoir's microscopic properties have significant influence on microscopic seepage feature. This passage analyzed the effects of factors like wettability and oil/water viscosity ratio on the water flooding process from the aspect of microscopic seepage mechanism. The dynamic displacement model, which reflects micro-flow mechanism, is built on the base of consideration of the microscopic characteristic impact by using the pore throat structure of cores. The structure is achieved by mercury capillary beat experiment. The relative permeability curves under different pore throat characteristics are obtained by solving the model. Then model's accuracy is verified by experience. Finally, the effects of wettability and oil-water viscosity ratio on the variation of relative permeability are analyzed.Taking the geologic characteristic of depositional microfiches from the target areas as evidence, in this passage we built geologic model which can reflect the macroscopic heterogeneity differences of different depositional microfiches, and substituted the oil/water relative permeability curve into macroscopic numerical analogue. By comparing this calculation result with the stimulation result which ignored the difference of microscopic seepage characters, we know that microscopic seepage characters of reservoir have a great influence on water and oil distribution.This passage shows that, we can get more accurate result of oil/water seepage characters by studying formation oil/water flow principles with micro and macro level integrated. So it has instructive significance to the study of residual oil distribution.