Study On The Multi-Point Geostatistical Modeling Of Typical Fracture-Cavity Units In Tahe Oilfield

The Ordovician carbonate fracture-cavity reservoir were strongly tansformed and have characteristics of deep burial,diverse reservoir types and strong heterogeneity.It is difficult to establish a three-dimensional geological model that can accurately describe the shape of the reservoir,which restricts the subsequent development of the oilfield.In this study,we take the TH12207 well area in Tahe Oilfield as research area,comprehensively applies outcroop,well logging and seismic data to establish discrete models and attribute models of different types of reservoirs using different random simulation methods such as multi-point geostatistics.Training images of palaeo-subterranean river and fault-controlled cave reservoirs were established using multiple methods.Digitized the planar shape of two large caves of modern karst outcrop in Zhangjiajie,Hunan,and established training images of palaeosubterranean river reservoir based on field outcrop;Using seismic carving technology,a training image of palaeo-subterranean river reservoirs based on seismic attribute data was established;According to statistics of Bachu outcrop caves in the Tarim Basin,training images of different shaped fault-controlled cave reservoirs were established.Probability bodies for different types of reservoirs were established.Calculate the relationship between the development of different types of reservoirs and faults,paleoriver,seismic attributes to build probability bodies under single-factor control.Fusion of multiple probability bodies using probability fusion method to establish orresponding development probability bodies for different types of reservoirs.Multi-point geostatistical simulation method is used to establish discrete distribution model of palaeo-subterranean river and fault-controlled cave reservoirs.By analyzing the simulation results of different training images,select the suited training image.Analyze the relevant parameters involved in the modeling process,select the appropriate simulation parameters for simulation.On this basis,the sequential Gaussian simulation method was used to establish the attribute models of palaeo-subterranean river and faultcontrolled cave reservoirs.Sequential Gaussian simulation method was used to establish a discrete distribution model of weathering crust reservoirs;Hierarchical modeling idea is used to establish fracture model;Based on this,sequential Gaussian simulation methods are used to establish the attribute parameter models of various types of reservoirs,Then each discrete model is fused to obtain the final three-dimensional geological model.