The Division Of Flow Units In Low Permeability Reservoirs

With the increasing importance of petroleum in the national economy and the growing difficulties in exploration of the mid- and high permeability reservoir, the importance of the exploration and development of low-permeability reservoir, which mainly consists of lithological reservoir and structural reservoir, draws more and more attention. The amount and the output of low-permeability reservoir will increase with the thorough exploration and the elevation and perfection of development techniques. Exploration and development of low-permeability reservoir has become one of the important potentialities for the stable development of terrene petroleum industry. Therefore, the development of low-permeability reservoir is essential for the Chinese petroleum industry.Guided by the theory of contemporary high-definition stratigraphy, with the employment of microscope, and SEM to observe and analyze the micro-poro structure and lithogenesis of the three reservoirs, the observation of cores and a large amount of log datas, the thesis attempts to establish the frame of sequence stratigraphy with contrast and practicability, classify the reservoir into single-sandstone according to the sedimentary circle and systematically study the reservoirs both from micro-perspective and macro-perspective. According to the results obtained from the micro-perspective and the macro-perspective studies, by selecting the parameters representing the characteristics of the reservoirs to conduct the cluster analysis, discriminant analysis and regression analysis of all single-sandstone, the author obtains the plane distribution and portrait distribution disciplinarian of flow units and the relations with lithology, physical property, oil saturation and sedimentary microfacies. Meanwhile, the results are testified by the dynamic datas of reservoirs and micro- water displacement of oil experiment.The results shows that the differences of plane and portrait lie in not only lithology, physical property and micro-poro structure of different types of flow unites, but also the output of the reservoirs, the disciplinarian of oil-water movement and the distribution of residual oil. With the decrease of quantity of flow unites, the quantity of lithology, physical property and micro-poro structure of different types of flow unites decrease accordingly, and the same time, the output of the reservoirs decreases,the pressure of water injecting grows and the distribution of residual oil increases. From the correct result the means of flow unites division and parameters selection change with the structure setting, sedimentary characterization, datas accumulation and study administrative level of study purpose. For developing reservoirs which have abundance datas, large development area and strong inhomogeneity, required to be divided to single-sandstone, the microcosmic study of porosity structure and reservoir lithogenesis and macroscopical study of sedimentary microfacies should be conducted. The parameters used in the study include porosity, permeability, shale content, FZI, effective thickness, e.t. and the means used in the study include lithology-physical property, porosity structure,e.t. but for little area and slight inhomogeneity, the parameters include porosity or permeability or only FZI and means can use lithology-physical property in the flow unites division.