Research On Reservoir Heterogeneity Of Chang 2 In Bailangcheng Area Of Ordos Basin

After about ten years of oil and gas exploration at Bailangcheng area in Ordos Basin, which now have been at the stage of high water-cut. Because of complex of the distribution of the flooding situation and remaining oil, so needed research on reservoir heterogeneity urgently, revealed the accumulation of remaining oil, offer to scientific foundation for further water-flood development and water flood pattern adjustment.To solve the above problems, in succession on the basis of previous studies,based on analysis of a great deal of data of drilling and logging results of more than 230 development wells, many new theories and technological methods related to sedimentology, petroleum geology, geophysical logging and reservoir development geology are used in the paper, during the course of the study, many experimental analysis have been taken, such as thin section analysis, SEMP and mercury penetration analysis, ect. A series of studies of Chang 2 reservoir of Bailangcheng oil field have been carried, including fine stratigraphic classification and correlation, sedimentary micro facies, reservoir heterogeneity and accumulation of remaining oil, comprehensive evaluation and classification of the reservoir finally.Chang 2 reservoir of the study area is belonged to deltaic plain sub-facies of meandering steam, and the dominant sedimentary microfacies are point bar, natural barrier and flood plain,the point bar is the main reservoir bodies. The rock type is middle-fine grain feldspar sandstone. Cementing materials include self-generation chlorite and calcite,the intergranular pores and the denudation pores is the main pore space. The result of the mercury penetration experiment suggest that the reservoir has a characteristic of low initial expulsion pressure, moderate degree of sorting, slightly more coarse skewness and low ejection efficency, the communication of pore space is belongs to macro pore with thin pore throat type.The study reservoir has weak heterogeneity in both of in layer heterogeneity and interlamination with indistinct permeability aeolotropism, but the irregular distribution of interlayer have a great impact on the reservoir. Connectivity have a high degree of plane sand body. In the analysis of the impact of on the basis reservoir heterogeneity factors, according to the Reservoir Heterogeneity Indicator, the sandstone reservoir of Bailangcheng oil field can be comprehensive evaluation and classification, such as microtectonics, porosity, permeability,effective net sand and interlayer distribution, indicate remaining oil distribution, in order for future exploration and mining of remaining oil to provide scientific reference.