Reservoir Geological Modeling Of C Block In Changchun Oilfield

The C block of Changchun Oilfield is located on the five-star tectonic belt of the Luxiang fault depression in Yitong basin.Since its development in 1988,there have been nearly 30 years of history.The production in the block was high in the initial stage.After 3 years of production,the reservoir recovery rate decrease gradually,because the excessive liquid production had made the formation pressure reduced rapidly and the formation energy decayed.After many years' re-perforating,the layer of development were disrupted,making the further exploration and development of oil and gas limited.Since 2010,the oilfield entered the high water-cut period,its production fully declined in the block.As of 2013,all the wells shut down,the comprehensive water content was up to95.25%.The residual oil distribution is highly fragmented,the waterflood is inefficient,making it harder to control the rising of water content and to avoid the declination of production.In this paper,through dedicated research and analyzing the dynamic and static data obtained from the development of the Block C,we described the fine oil reservoir in the research area.A fine stratigraphic framework and a stratigraphic classification table of the second segment of Shuangyang formation in the C block are established by comparing the small layer of the area.The cores of the channel wells are observed and described,and 14 basic rock types and 13 sedimentary microfacies are identified with the logging curves.The micro-structure of the research area isprecisely figured out based on the data of layered strata,sedimentary microfacies and secondary interpretation of logging and development of dynamic data.Using the three-dimensional visualization modeling technique of Petrel software,the stochastic modeling and deterministic modeling,and considering the overlapping forms of the existing strata between different formations in the research area,interpolation of Kriging is used to improve the accuracy of the stratigraphic model.Based on the preliminary research results of the project and an artificial hand-crafted sedimentary microfacies,the sedimentary facies model of the block is established.In this model,by using phase-controlled modeling and sequential Gaussian simulation as well as the interpolation to predict the distribution of properties between wells,the attribute model of the C block is created.Moreover,the residual oil distribution model is established by integrating 3D geological model,numerical simulation data and production dynamic data.This model of the C block truly reflects the characteristics of current reservoir distribution and the actual situation of sand body spreading.By analyzing the relationship between the residual oil distribution model of the C block and the phase belt and the fault,it is found that residual oil distribution are mainly affected by two factors: the phase control and the tectonic control.Thus,the research confirms that the types of residual oil are determined by sedimentary facies control and by tectonic control.