Carbonate Reservoir Fracture Characterization In X Block,Neuquen Basin,Argentina

As the decline of traditional reservoir exploration and development,fractured reservoirs rising oil and gas production,has accounted for more than half of the entire oil and gas production.While the study of fractured reservoir still stuck in the qualitative evaluation,or quantitative research just for the borehole by using conventional logging and image logging.This thesis studies the X Block in Neuquen basin,Argentina,as the objectives.Integrating geology,logging and seismic data,we attempt to adopt new technology to do quantitative study for the fracture developed in the whole area.Fractured characterization contains defining the fracture orientation and density,length,open degree,etc.While fractured reservoir characterization includes fracture description,fracture distributed summarization and fracture developed prediction.This thesis depends on the integration of geology,geophysics and petrophysics,combining micro and macro.Based on fine structure interpretation,it is concluded that fault is main controlling factor for tectonic development.Research area developed two groups of faults.Faults in middle-east part developed earlier,with which small fault throw and short extended distance.While western faults has experienced a long geologic period,with big fault throw and long extended distance,trending near N-S direction.Fractures mainly developed in oolitic limestone and bioclastic limestone.Two types of fracture are classified based on dip angle,low angle fractures and high angle fractures.Low angle fractures are mainly affected by diagenesis,while the high angle fractures are mainly controlled by tectonic action.Most open fractures are low angle fractures,which mainly developed in the Huitrin formation.Oil and gas migration pathway and reservoir space are reserved because of the leaching process and dissolution.On the plane,diagenesis fractures are mainly developed in oolitic limestone belt and dolomized belt.While structural fractures distributed along the fault and nearby.Stress field numerical simulation results indicate that high strain area located near the fault,with which nearly W-E direction compressive stress.Huitrin formation and Agrio formation share the same stress field,both of which are mainly controlled by fault.Huitrin layer has the similar anisotropic distribution with Agrio layer.However,the anisotropic intensity of Huitrin is stronger than Agrio layer.The predict result based on anisotropy theory indicate that the orientation of fracture is nearly N-S direction and fracture density in western is stronger than middle and eastern.