3-D Geological Modeling And Distribution Of Remaining Oil Of Chang 2 In The Dingbian Zhanghan Area Of Northern Shannxi

Based on the current and actual situation of Dingbian Zhanghan aera, with the purpose of studying the distribution of remaining oil, by analyzing the structure, sedimentary microfacies, reservoir characters and oil reservoir characters, we found the fine 3D geological modeling, and based on the abundant dynamic monitoring data, using the dynamic oil-well monitoring analytic method and the comprehensive geological method, we analyze the distribution of macroscopical remaining oil in the study aera, and make some adjustment suggestions of oil region development. The following researching results and achievements are obtained in this paper:Through subtly stratigraphic correlation in the study aera, Chang 2 oil-bearing can be divided into Chang 21, Chang 22, Chang 23. Further more, Chang 21 can be divided into Chang 21-1,Chang 21-2 and Chang 21-3.Based on the regional sedimentary background, combined with facies indices and the formers'achievement in research, on the base of the fact that Chang2 belong to the distributary channel deposits of lake delta plain, further divided it into 4 micro-faces including distributary channel which is considered to be the main reservoirs of the area, and based on this, the the sand thickness maps and sedimentary micro-face maps have been established respectively, then analyzing the plane distribution and the regularity of microfacies of the three separate subzone.The Chang 2 reservoir in the study area is medium to fine arkose and lithic arkose. The main pore configuration are intergranular pore and emposieu pore. The main lithogenesis are compaction and pressure solution, cementation and dissolution. Effect of lithogenesis, the Chang2 sandstones is medium porosity, low-extremely low permeability, the average porosity is 15.88% and the average permeability is 8.261×10-3μm2. It is held that the pore throat structure is the type of medium pore and medium-fine throat. In addition, the study of diagenesis showed that the Chang2 reservoir diagenetic stage with late-diagenetic stage-A. Based on overall analysis,the results showed that the main type of reservoir are I and II b.The traps are mainly structure-lithology trap, oil in the study aera is the general continental crude oil with the characteristic of low density and moderately viscous, the formation water is mainly belong to chloride-calcium type. The Chang2 geothermal gradient is about 2.49℃/100m, which belong to normal temperature and pressure conditions.Making use of petrel software, using the methods of sediments cortrolling and random modeling, on the based of the abundant geological knowledge base, with the restriction of sedimentary facies and geological conditions, we established the 3-D geological modeling of Chang21-1, Chang21-2, Chang21-3 in the study aera, which including the structure model, the facies model, the attribute model of porosity,permeability and oil saturation.Using the dynamic oil-well monitoring analytic method and the comprehensive geological method, we analyzed the distribution of macroscopical remaining oil of main Reservoir-Chang21-1 subzone in the study aera, mapped the prediction diagrams of two-dimensional distribution of the macroscopical remaining oil of Chang21-1 in the aera, and make some adjustment suggestions of remaining oil region development.