Fine Interpretation Of The Jurassic Structure And Reservoir Prediction In The Grape Ditch-Portuguese Region Of The Tuha Basin

The Tuha Basin Putaogou-Pubei Area is characterized by its fault development,good-quality reservoir and abundant oil and gas resources.Based on the project of Development Department in CNPC Tuha Oil Field Branch Company,employing Qiketai and Sanjianfang Groups of Jurassic system in Putaogou-Pubei Area as research objects,the structural features and evolution of the study area was deeply analyzed by using the newly acquired and processed 3D contiguous earthquake data and the fine interpretation data by means of coherence technology,curvature analysis technology,map analysis method and variable velocity mapping technology.Meanwhile,under the condition of the exact information of the structural features,after analyzing normal wave impedance inversion method's advantages and disadvantages,this paper introduced a new type wave impedance inversion method-earthquake waveform simulation inversion method to anticipate the thin reservoir of major goal layer.The research results show that the Jurassic series structure in Putaogou structure possesses the characteristics of "north-south zoning" and the hanging wall and footwall of the faults in the Flame Mountain are divided into three lines of structural belts,that is footwall traction anticline belt,south anticline belt and north slope belt.The Pubei structural belt is distributed in south-north direction,and the subject of structural belt was formed in early Yanshan epoch.It was strengthened in the middle and late Yanshan epoch and set in Himalayan epoch.Influenced by west Bu'erjia's continual uplift and north mountain front thrust-nappe,the structural form demonstrates high south and low north,north-south zoning and east-west partitioning in overall.Because of the limitation of earthquake frequency width and well location uniform distribution,the conventional sparse impulse impedance inversion and geological statistics wave impedance inversion cannot conduct accurately anticipation to the thin reservoir of this area.While the earthquake waveform indication simulation inversion method has some advantages over the conventional methods:first of all,it is relatively independent to initial model,and it can reflect the underground sedimentary environment and the space variation of lithological association through earthquake waveform;secondly,it has the inversion results which are more identical to the drilled well natural potential curve as well,and has natural well sand change and no well interpolation phenomenon.As a result,it can gain more reliable inversion results to accurately anticipate thin reservoir.Conducting optimization toward exploration targets through above structure development and reservoir favorable area has relatively better supporting effect to conduct well location arrangement development and reservoir description of this area.