Research On4-D Reservior Geologic Model Building Of Sa Ⅱ In Central X6District In Daqing Oil Field

4-D reservoir geological modeling is mainly focused on excessive development reservoir, which has been exploited for a long period, or its injection-production pattern has been adjusted for many times. Through the abundant geologic, logging data and dynamic data provided by the oil fields, or petrophysic data gained from laboratory testing technology of the core sample before and after washing, a mathematical model for the geologic parameters’evolution of underground reservoir units and also a4-D geology model are set up, based on the fine reservoir description theory. Therefore, the distribution of remaining oil, which is changed with the water flooding degree can be reflected clearly.A method of building a4-D geological modeling is put forward, according to current development situation of central X6district of Xingshugang oil field. Integrated using the theory of reservoir geology and boreholes, logging, well testing and dynamic develop data in the study area, a systematically4-D geological modeling method and train of thought are determined for the study area. First of all, the characteristics of sedimentary reservoir units are clear through a large number of geological basic researches. On this basis, a dynamic change of reservoir is tracked with oil reservoir development phase as the fourth dimension, by combining the static research with dynamic study, in order to reveal the evolution of the reservoir parameters in the reservoir development process. Those parameters contain the distribution and evolution law of reservoir heterogeneity, as well as the advancing direction of injected water in reservoirs, the change of sweeping scale of SII section of central X6district in Xingshugang oilfield, so that a4-D geological model with the development process for longitudinal is established.In this paper, methods for establishing a4-D water flooding model are discussed in detail. There has been four sets of injection patterns in Central X6District since1968. The performance of water cut oil well is analyzed and the evolution of water-flooding situation in plane and profiles is uncovered by analysis of water flooding data which are explained from the well logging. The improvement on the water flooding data of basic well pattern, encryption patterns at a time, twice and three times can provide the input parameters for the4-D geological model. According to the data characteristics of central X6district, the dynamic tracking analysis method is used to establish4-Dwater flooding model in this study. Firstly, the water flooding situation of basic well pattern and the encryption patterns at a time is analyzed in the whole, in order to study the distribution of water flooding in the first encryption stage. And the sweep degree of injected water in that stage is predicted, with the facies controlling. And then, complement the water flooding data with one time encryption. The water flooding distribution model with one time encryption is set up under facies control. In the same way, the water flooding models with twice encryption and three times encryption under facies control are built. These3models of each stage are complementary and mutually binding, and ultimately,4-D water flooding model of central X6district can be gained.Through establishment of the4-D geological model of the study area, the difference of water flooding feature in various injection stages can be revealed. Overall, Sa II section in central X6district develops from non-flooded to high-flooded, and the flooding degree changes in the different areas. The distribution of remaining oil can be changed with the spread and sweep of injected water, which can be visualized by4-D water flooding model directly. In this study, the motion regular pattern of oil and water in reservoir is revealed, and the source injected water is tracked to analyze the sweep range and spread direction, in order to predict the promising areas of remaining oil in the low-water flooding and no water flooding areas. In further, it can lay a good foundation for follow-up reservoir development adjustment and remaining oil development.