| Qingxi Sag is the major oil-bearing depression of Jiuxi depression. At present, the production is declined and the reserve-production is imbalances after the years of exploit. The sustainable development is faced with serious challenges. As the structure of the sag is complex, the lithology is variable, the gathered oil and gas is buried deeply, it is difficult to grasp the regularity of hydrocarbon enrichment patterns. It is needed to excavate the potential and find out remaining oil distribution on the detection and the research in many aspects. It can be good to carry out the fine reservoir description by set up quantitative reservoir geological model in the study area.On the basis of taking the reservoir objective and comprehensive, predicting the regularities of distribution on the inter-prediction Wells sand and reservoir parameters.Taking Xiagou Formation, Lower Crataceous Kulongshan area in Qingxi Sag, Jiuquan Basin as the research object, studying on reservoir three-dimensional geological model which provides reference for the oil and gas field development and management as well as program adjustment, etc.Start from the characteristics of reservoir itself in Kulongshan area, carring out the detailed stratigraphic division and correlation combined with the structure characteristics, stratigraphic features, sedimentary characteristics and reservoir characteristics of the studied area on the basis of the well logging, drilled well, well testing, core analysis data, seismic data and litho-electric experiment data. The target layer is divided to 19 small layers which is Klgl4、K1g14-2、K1g14-1、K1g13、 K1g13-2、Klgl3-1、K1g12、K1g12-2、K1g12-1、K1g11、Klg11-2、K1g11-1、K1gO4、 K1g04-2、K1gO4-1、K1g03、K1g03-2、K1g03-1、K1g02 in Kulongshan area. The high resolution isochronal stratigraphic framework is established in the study area.The study area is constituted with the fan delta plain subfacies, fan delta front subfacies, shallow lake and deep lake. The provenance direction is mainly in the north west. On this basis, carring out the reservoir three-dimensional geological model of the study area by using the petrel modeling software.There is three steps to completing the reservoir geological model. The first step is the establishment of the structure model, the second step is the phase model, the third step is the attribute model. The structure model of Qingxi Sag use the conventional process, and the structure model of the Kulongshan area is coarsened directly from the structure model of Qingxi.To choose reservoir modeling methods which can best reflect the varying pattern of the geological reservoirs variable in the actual space is the key to the sedimentary facies model in the stand or fall. This paper take deterministic modeling methods and random modeling method to estabilish sedimentary facies modeling respectively in the study area. Then combining the advantages of deterministic modeling methods and random modeling method to establish the combination of deterministic and stochastic simulation model.The deterministic three-dimensional sedimentary facies model which is about the distribution of fan delta plain, front and shallow lake mudstones is established by the sedimentary microfacies distribution figure. Combined with regional variate of reservoir and the variogram, the stochastic sedimentary facies model is about the spatial distribution of rock using sequential indicator method. The combination of the deterministic model and stochastic model is to constraints on each other and improve the accuracy of rock facies model.Finally,with the rock model as constraints, the three-dimensional distribution models of porosity and permeability are established using the Gaussian sequential modeling method.The model shows spatial variation characteristics of reservoir aeolotropism intuitionisticly, and guides the oil-rich area remaining oil mining effectively. It provides a solid geological foundation for the subsequent reservoir research and reservoir numerical simulation. |
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