Sedimentary Facies Analysis And Multi-point Geostatistical Modeling Of Typical Thin Sandstone Reservoirs

With the development of exploration and exploitation, more and more geologists devote themselves to studying the characteristics of thin sandstone reservoirs, for which it has higher heterogeneity in petrophysical property.lt is the heterogeneity that strengthen the complexity of fluid distribution characteristics, and make it more difficult to research the distribution pattern of remaining oil. Therefore, it also affect the optimization for exploration and development, and then hinder the realization of high and stable productivity. Sedimentation is also the main factor of controlling sand distribution. Therefore, it is of great practical significance in accurate facies analysis and facies modeling of thin sandstone reservoir.With the extensive application of multipoint geostatistics in facies modeling, the active role played by complex geometrical statistics in the complex morphology and precision improvement is beyond doubt. Therefore, it is more effective than other conventional simulation methods, Target stochastic simulation can meet the requirements of geologic development of oil and gas reservoirs in the high water cut later stage.Facies modeling is mainly to characterize the superposition of the microfacies in the plane and vertical. The sedimentary environment is the decisive factor of the sedimentary characteristics. Therefore, the palaeoclimate, offshore distance and palaeostructure, The thin sandstone reservoir of Xibei Formation in Qaidam Basin with different oil and gas layers and the different well density, and the thin sandstone reservoir of Shahejie Formation in Shahejie Formation of Bohai Bay Basin. Based on the newly collected data, the sedimentary microfacies is analyzed, and the multi-point geostatistics method is used to study the facies modeling.On the basis of the analysis of multi-point geostatistics method and the discussion of the flow, the training image is researched from the aspects of grids setting, division of smooth region, selection of making method and parameter setting and quality inspection of training images. Based on the above results, the model was optimized by the single-variable analysis, and the reliability and stability tests were carried out by searching the model radius, the multi-grid series and the maximum number of nodes in the sub-grid. Finally, the model of the shore-shallow lake facies and the lake-bottom fan facies is simulated.From the aspects of morphological representation, precision and applicability, the method of multi-point geostatistical facies modeling is evaluated by comparison with sequential indicator simulation method and object-based stochastic simulation. The relationship between modeling parameters and simulation results is analyzed by univariate analysis, and the basis and criterion of parameter optimization are summarized in order to promote the multi-point geostatistics in other reservoir sedimentary facies modeling Which can provide a reliable basis for the modeling of phased-controlled properties, and then provide accurate data for the evaluation of reserves, dynamic analysis and numerical simulation. It can guide the quantitative description of multiphase flow in time and efficiently, as well as oil and gas field development plan Of the adjustment.