Seismic Prediction Of Tight Clastic Reservoir In Ordos Area

Ordos Basin is one of the most active basins in oil and gas exploration and development in China in recent years,with the fastest growth of oil and gas storage and production.The tight clastic gas reservoir of Upper Paleozoic is the key field of natural gas exploration in this basin.Since the discovery of Yulin gas field in 2000,more than ten large-scale tight clastic rock gas fields have been discovered and proved successively,and rich exploration and development results have been achieved.The results show that the sand body of tight clastic gas reservoir controls the enrichment and distribution of natural gas obviously,and the high-quality and efficient reservoir is the main controlling factor for the enrichment and high-yield of natural gas.Therefore,it is of great significance to study the prediction method of tight clastic reservoir and accurately grasp the geometry form,spatial distribution characteristics and the spatial distribution law of physical property and gas bearing property of the reservoir in order to delineate the favorable exploration target area,reduce the exploration risk and improve the success rate of drilling.Taking a block in the north of Ordos Basin as an example,this paper takes sedimentology,sequence stratigraphy,reservoir geology,well logging geology,seismic stratigraphy,geophysics and other multidisciplinary theoretical methods as guidance,relying on drilling,logging,logging,core,testing,seismic and other data,in stratigraphic sequence division,sedimentary facies research,seismic data target processing and logging rock On the basis of physical analysis,using high-resolution and fidelity seismic data,using model forward modeling,seismic inversion,seismic attribute analysis and other methods to carry out reservoir thickness and gas bearing prediction and comprehensive evaluation,exploring the ideas,methods and parameters suitable for tight clastic rock reservoir prediction in the study area,accurately predicting the reservoir thickness and gas bearing characteristics,and optimizing the advantages through comprehensive evaluation The location of exploration.The paper considers that the anti-Q filtering can improve the resolution of the original post stack seismic data,and the decomposition of seismic wave waveform and the reconstruction of multi wavelet are conducive to eliminate the coal seam shielding effect;the P-wave impedance and the P-wave velocity ratio are the sensitive rock physical parameters to distinguish the coal seam from the non coal seam and the sandstone from the non sandstone respectively;the combination of the post stack wave impedance inversion and the pre stack AVO simultaneous inversion method can be used to Effective prediction of reservoir thickness and plane distribution characteristics;pre stack AVO "bright spot",pseudo Poisson's ratio change rate,fluid factor and post stack high frequency attenuation and other attributes can qualitatively predict the gas bearing property of the reservoir;comprehensive evaluation of reservoir prediction based on the prediction results of reservoir thickness and gas bearing property can better delineate the favorable area for reservoir development.The paper has 140 pictures,9 tables,and 102 references.