Reservoir Prediction Research In WLK Area In Southwestern Tarim

Located in the Kekeya tectonic belt,southwest Tarim Basin,WLK area is placed on the south margin of the Yecheng Depression.It belongs to the secondary structural belt in the piedmont zone of the Kunlun Mountains.For Tarim Oilfield,this area which is rich in hydrocarbon has been a key exploration block of the piedmont zones of the Tarim Basin in recent years.The overall structure of WLK belt is relatively uniform and simple,presenting as a single anticline from shallow to deep.Formed during the Early Himalayan period,the structure is deeply buried with strong heterogeneity.Multiple wells drilled in the area had poor production performance,indicating that the extreme complexity of the target formation Kalataer Formation.The low accuracy of reservoir and fracture prediction in earlier researches can not meet the urgent need for accurate reservoir prediction and exploration area optimization to accelerate the exploration and development of carbonate condensate gas reservoirs in the Kalataer Formation.The dissertation focuses on the study of the Paleogene Kalataer formation in the WLK area of the southwest Tarim Basin and uses a variety of methods to carry out reservoir prediction research.In the dissertation,based on data from logging,cores,and seismic survey,comprehensive analysis of geological characteristics of the Kalataer Formation is conducted to characterize the distribution,orientation and degree of development of fractures in detail by using methods including coherency analysis,post-stack AFE fracture detection and FRS azimuth-stack fracture prediction.Three fracture strips lying southeast are discovered in both the main body and the north and south limbs of the structure.The fractures in the beach body are well developed with good connectivity,making it a favorable hydrocarbon accumulation area.Two methods,constrained sparse pulse inversion and geostatistical inversion,are used for the reservoir inversion in the study area.Comparing the results of the two methods,it is found that the phase-control statistics inversion achieves a better result.The inversed reservoir data shows good lateral continuity.The inversion resolution is significantly higher than that of the conventional constrained sparse pulse inversion,which can more accurately reflect the reservoir characteristics of the study area and make detailed reservoir prediction.Integrating the information including seismic attributes,fracture development,sedimentary facies,AVO oil and gas detection,etc.,favorable reservoir distribution zones are optimized in the study area,providing supports for well site deployment and exploration and development in the next study area.