Reservoir Distributed Seismic Prediction Of The Fourth Section Of Dengying Formation In Gaoshiti Area

Carbonate reservoir plays an major role in oil and gas production.In foreign countries,carbonate reservoirs are extremel concerned.In the domestic,marine carbonate has become an important part of China's energy strategy.It is a significant oil and gas exploration field in China after continental clastic rock.Gaoshiti area lies Suining city,Tongnan of Chongqing,middle of the Sichuan basin.Low hilly area,a simple geological structure,gentle fold.In July 2011,after the acidification test of Gao Shi 1 well,the daily output of natural gas reaches millions of cubic meters,which made Gaoshiti area become a hot spot in recent years.This paper is based on core data,slice data,logging data,and seismic data,guided by multidisciplinary theories of oil and gas geology,sedimentary petrology,reservoir geology,mineralogy,geophysics,and geostatistics,geological-geophysical combination is the main line.Full understanding of the geological background of the block.Based on the full understanding of the geological background of the block,reservoir characteristics analysis,reservoir geophysical response characteristics analysis,seismic sensitive attribute extraction,and impedance inversion of seismic waves are performed.Finally,favorable reservoir blocks are evaluated.This paper has important guiding significance for choosing exploration targets and development of gas reservoirs in the later period.At the same time,it also provides basic preparations for the development of the second section of Dengying gas reservoir.Through rock core and slice observation,the characteristics of rock types in the study area were determined,combined with the comprehensive analysis of regional geological background.It is believed that the fourth section of Dengying Formation in this area is characterized by the deposition of the carbonate platform and the development of the five major sub-facies of the mud mounds,the grain beach,the mounds beach complex,the lagoon,and the tidal flat,among them,mud mound,grain beach and mound beach complex are the most important subfacies.The type of reservoir space is dominated by secondary pores.Using geologic-seismic methods,the geophysical response characteristics of the fourth section of Dengying reservoir are analyzed: the head of Dengying strong amplitude attenuation,internal weak amplitude,bifurcation of events,the merger of events,increase in the number,frequency increase and combining forward modeling with possible geologic genesis of seismic response characteristics.Considering the heterogeneity of carbonate reservoirs,three kinds of seismic sensitive properties,such as high frequency attenuation gradient,low frequency energy increment and tuning energy,are adopted,combining wave impedance inversion,using drilling test data as inspection,three types of favorable zones are divided in the fourth section of Dengying in Gaoshiti area,including seven type I,five type II,three typeIII.In general,northwest and east of the study area are favorable blocks for the development of reservoirs.