Seismic Identification Of Carboniferous Volcanic Rocks In The Western Section Of Dinan Uplift And Prediction Of Favorable Exploration Areas

Volcanic reservoirs play an important role in the oil and gas resources of Junggar Basin,especially Carboniferous contains abundant oil and gas in the Dinan salient of the eastern part of the basin.But complex lithology,strong lateral heterogeneity,strong structural deformation and complex distribution of oil and gas exist in reservoirs of Carboniferous volcanic rocks,especially,the large burial depth of Carboniferous,the poor quality of seismic data and the difficulty of identifying volcanic traps,these problems restrict the expansion and new discovery of Carboniferous reservoirs in the Dinan salient.In this paper,the Carboniferous volcanic rocks in the western section of the Dinan salient in Junggar Basin are taken as the research object,and the 3D seismic processing data of a large area are taken as the basis,combined with the two dimensional seismic data in the sag area and the downhole drilling data,through fine seismic geological horizon calibration and the comparison of seismic interpretation profiles of the regional grid,the unified interpretation scheme of logging and earthquake for the Carboniferous and the seismic response characteristics of the Carboniferous volcanic rocks in the study area are established.The fine structural interpretation of the Carboniferous and adjacent strata in the study area was carried out,and the basic structural morphology of the Carboniferous was clarified.Combined with the structural evolution analysis,the paleotectonic characteristics of the Carboniferous roof in the main overlying geological period in the study area are defined.Based on the analysis of the single well facies and the seismic forward modeling,the corresponding relationship between the volcanic facies and the seismic facies in the study area is established.Through the analysis of seismic facies,the plane distribution characteristics of various seismic facies are pointed out.At the same time,the plane distribution characteristics of volcanic facies and the development area of favorable volcanic facies body are determined in combination with gravity and magnetic anomaly data.It is considered that favorable lithofacies zone(overflow facies,explosive facies,volcanic channel facies)are mainly distributed in the north and south convex zones of the Dinan salient,in which the volcanic channel facies rock body distributes sporadically in the uplift zone.Using seismic attribute technology and seismic waveform characteristics to identify the Carboniferous volcanic trap,and to predict and evaluate the distribution characteristics of lithology and physical properties of volcanic rock reservoir in the trap.Based on the comprehensive analysis of the characteristics of structure,lithofacies,attributes and petroliferous properties,the favorable areas for Carboniferous exploration in the western section of the Dinan salient are finally determined.It is considered that the structure of the east convex zone of well Ditan 1 and Dixi 2 is favorable for further exploration,with favorable structure,volcanic facies and good reservoir.