Structural Interpretation And Reservoir Prediction Of Nantun Formation In Nansagao Of Block X

With the continuous improvement and breakthrough of petroleum exploration technology.The huge oil and gas reserves in the Tamtzag Basin have attracted widespread attention.However,due to the scattered distribution of oil reservoirs in the southern sag of Block 21,well-developed faults,complex structures,and unclear understanding of reservoir characteristics,this has brought huge challenges to oil and gas production.Therefore,this article uses well-seismic combined with fine structural interpretation to analyze structural characteristics.At the same time,the sedimentary facies model is used for constrained inversion to achieve the purpose of fine reservoir prediction,and then to achieve the prediction of favorable areas.This research is based on existing seismic data,logging data and logging data.Under the guidance of sequence stratigraphy theory,carry out horizon calibration.Interpretation of horizons and faults in the entire region based on synthetic seismic records,and analysis of structural characteristics of the Nantun Formation in Block 21.The results show that the Nantun Formation structure is high in the east and low in the west,forming a "sag-up-slope" structure from south to north,forming a structural pattern of reversal zone,transition zone,ring depression zone and depression zone.The faults are mainly northeast trending,and a series of traps of varying sizes develop along the main fault zone.In the division of sedimentary microfacies,the provenance direction is determined by combining the regional sedimentary background and core data,and the deposition model of the area is established.The depositional system is dominated by fan delta deposition,and the northern part of Nantun Formation in the Nansag is a steep-slope fan delta deposition model,and the south is a gentle slope fan delta deposition model.According to the analysis of singlewell facies,continuous-well facies and seismic facies,it is established that the distribution of sedimentary microfacies in the study area is characterized by a large lake basin area in the first section of the south.The delta plain mainly develops in the northeast,the western and northern river channels are small in scale,and the river channels are mainly dry and branch-shaped.The second member of the south is the source of the lake basin as a whole injecting sediments.The delta plain mainly develops the main source of the northeast,and the underwater distributary channel mainly develops in the southern depression.According to the statistical results of lithology and oil-bearing properties in the study area,the oil-bearing lithology is diversified and the vertical difference is obvious.In order to improve the accuracy of reservoir prediction,the lithology and layered curve reconstruction method is adopted in the inversion,and the multi-parameter fitting reconstruction inversion is used to quantitatively characterize the reservoir characteristics.The prediction results show that the sandstone is distributed in a north-west trending band as a whole,and the thickness of each small layer of sandstone is mainly between 2m-10 m,and the maximum can reach 61.4m,with well-developed reservoirs.On the basis of comprehensive structure,fault,reservoir and sedimentary microfacies research.Based on the oil-water distribution law and the accumulation model,comprehensive regional geological conditions,structure,traps,oil-water distribution and reservoir development and other research results.Three types of favorable areas are identified: favorable areas for accumulation of reserves,potential areas for expansion outside the reserves,and favorable areas for exploration in blank areas.