Prediction Of Favorable Exploration Areas And Identification Of Lithologic Traps In The Upper Wuerhe Formation In The West Sag Of Well Pen 1

The Pen-1 West Well depression in Junggar basin is located in the main direction of hydrocarbon migration in hydrocarbon-rich sag.The Permian-Triassic which develop relatively high-quality reservoirs in front facies belt have similar tectonic and sedimentary backgrounds with the slope of east of Mahu sag.It has favorable oil and gas accumulation geological conditions.It is the key exploration field after the oil and gas discovery of the Baikouquan Formation in the Mahu depression,Junggar Basin.Based on the 3D seismic data and the newly acquired 2D seismic data,a unified seismic geological interpretation scheme for the Permian Upper Wuerhe Formation in the Pen-1 West Well is established.A contiguous fine structure interpretation is carried out on the ring zone of the Pen1 West Well depression.The structural form,fracture characteristics and plane distribution range of the upper Wuerhe Formation on the target layer of the study area are basically implemented.The sedimentary thickness method is used to restore the paleo-geomorphology of the Upper Wuerhe Formation during the sedimentary period.And the important controlling effects of the paleogeomorphology and the slope-break zone on the sedimentation of the Upper Wuerhe Formation sand body are analyzed.Seismic facies of Upper Wuerhe Formation are analyzed by using seismic waveform classification techniques.Combined with the fan delta sedimentary model,the distribution range of various sub-phases and the distribution characteristics of each sector under the fan-delta sediments of the Upper Wuerhe Formation are effectively identified.Seismic inversion,seismic attribute analysis and seismic forward modeling are used to predict the sand body of the Upper Wuerhe Formation and its overlying strata Baikouquan Formation.And the spatial distribution features of the Upper Wuerhe Formation and Baikouquan Formation sand bodies were clarified.Based on the above research results,it is pointed out that the southern platform area of the XY1 well is the most favorable exploration area of the Wuerhe Formation in the ring zone of the Pen-1 West Well depression.And a drilling well position is proposed in the favorable area,which lays the foundation for the next exploration work in the ring zone of the Pen1 West Well depression.