A Study On Micro-pore Structure And Infiltrating Characteristic Of Chang-6 Reservoir In Xuecha Area Of Wuqi Oilfield

With the the techniques of grain size analysis, pore image, casting section, SEM, high pressure mercury penetration, rate-controlled mercury penetration, relative permeability, water/oil displacement experiment, NMR, and x-ray diffraction analysis, the thesis makes a thorough research, focusing on reservior's pore structure and Infiltrating Characteristic of Chang-6 Reservoir in Xuecha Area, and the impact of sediment and diagenesis on pore structure character. The conclusions go as following:(1) The types of reservoir pore and throat are various in Xuecha Area. The main reason of low permeability reservoir in the region of interest is that micro-pores are more than dissolution pores, another reason is that pore connectivity is poor. Low coordination number of pore-throat also can make the low permeability reservoir.(2) Throats is the key factor for the ability of flow in low permeability reservoir, Even though there are a little wider throats,they have made great contributions to the permeability. At the beginning of mercury injection, the total pressure curve and pore preesure cure are consistent. With the increasing of mercury injected pressure,the trend of total pressure curve depends on the form of the throat preesure cure.(3) The parameters which make more effect on reservoir in the region of interest are as following:principal stream throat radius, maximum throat radius, medium radius and mean value,. The wiser the throat radius sizes and the smaller the mean value get, the better the reservoir's pore structure and the physical property.(4) The results of oil/water displacement experiments demonstrate that different models because of the diversity in lithology, physical property and pore structure display differently in the process of oil saturation, displacement, residual oil type.The parameters of the reservoir in the region of interest are not only low, but also have serious heterogeneity. The micro-pore structure is the crucial factor affecting these parameters.(5) The physical property is obviously controlled by the sedimentary facies, underwater distributary channel's physical property is better than underwater natural barrier s.Although under the same diagenetic histories, the intensity of diagenesis function is differert. Therefore, there are different porosity evolution histories, which are embodied the discrepancies of pore struetures and reservoir properties.