Structural characteristics and gas accumulation in the deep of the Changling Fault Depression,the South Songliao Basin

Large 2D seismic sections,3D seismic data,and drillinglog data,combined with high-accuracy gravity,magnetic and electric survey data,were used in a systematical analysis of the regional geological structure in Changling fault depression.It is suggested that the Changling fault depression is not a simple single fault depression but a complicated fault depression cluster,which is composed of many primary and secondary fault depressions and connected with the northern part of Gulong fault depression.Structural units and plays in the area are identified based on integrated industrial mapping.Geometric and kinematic analyses of the main faults are also carried out and based on that,the structural evolution of the fault depressions is studied and divided into the following three periods: basement formation,fault depression development,and modification.With analyses of petroleum geological conditions,the accumulation characteristics of different gas reservoirs are studies and potential exploration targets are defined.