Seismic Detection Methods Of Heterogeneous Carbonate Fractured Reservoir And Applications

Fractures in carbonates are of great significance for the exploration and development of oil and gas reservoirs.The Ordovician carbonates in the target Tahe oilfield experienced weathering crust karstification in the Late Caledonian-Hercynian.It forming complex karst landforms and dissolution fracture-cave systems.The main reservoir is the Ordovician carbonates fracture-cavity reservoir.The karst cave and hole are the main reservoir spaces,and the fractures is the main connecting channels.With the deepening of the development of fracture-cavity carbonates reservoirs,the exploration and development of oil and gas is becoming more and more refined,the reservoirs of oil and gas are becoming more and more complex.And the exploration targets are continuously transferred to lithologic reservoirs and subtle reservoirs.It is increasingly important to identify the lithologic spatial distribution and internal structure of oil and gas reservoirs.Both the more accurate description of different types of carbonate fracture-cavity reservoirs and the Identification of spatial distribution and internal structure of underground fractured reservoirs are of particular significance for the exploration and development of oil and gas.In this paper,the description technique of the fractured hole unit and fracture hole body that have been formed in the target work area is studied.In order to enable multi-scale hierarchical characterization,the multi-scale coherence based on Curvelet transform and three-dimensional multi-scale body curvature attribute methods are cited.Compared with the traditional algorithm,the improved curvature and coherence algorithm has multi-scale characteristics.Edge detection based on two-dimensional Hilbert transform can directly process two-dimensional data.The introduction of Gaussian functions and 3D window functions gives it the ability to reduce noise.Moreover,it can well interpret the discontinuity information in 3D seismic data.For reservoir interpretation in complex terrain,the use of a single seismic attribute method does not provide a good indication of the underground geological structure.Fracture detection method based on seismic attribute fusion combined with the target of seismic interpretation,screening a single attribute method and according to its characteristics,finally formed an interpretation method of different scale fault-karst.Aiming at the unique regional geological situation of the target area,the target area is analyzed in detail.In this paper,seismic grading prediction methods based on artificial ants,Curvelet coherence and multi-scale body curvature are respectively formed in different fracture-cavity units.And the detection method for fault-karst has been initially formed,includes the detection of its main fracture,boundary and inner cave.Based on the characteristics of seismic data in actual areas,this paper develops comprehensive analysis and research on multi-attribute seismic detection methods,and creatively adds a new edge detection attribute algorithm.It can explain the different scales,especially the large-scale crack boundaries,associated cracks and inner curtains,and finally realize a more accurate description of different carbonate fracture-cavity reservoirs.