Study On Prediction Methodology Of Yanchang 7 Tight Oil Reservoir Dessert In Anbian Area

Oil and gas resources in Ordos Basin is abundant,An83 block is located in the middle of the Yishan slope.After decades of exploration and development,evolutional breakthrough has been made in Mesozoic oil exploration.Especially in recent years,Chang 7₂ member of An83 well tight oil exploration and evaluation have achieved significant progress.In 2014,100.6 million tons proven reserves and 258.01 million tons forecast reserves in Chang 7₂ member of An83 well have been submitted;It became the first billion tons of large tight oil field in China.Strengthening Chang 7 member tight oil reservoir research,well site optimization,technology research and development of well trajectory design have been used in order to improve the ability of seismic identify reservoir,and to provide technical support for reserve submission.In the An83 well,seismic interpretation and mapping was used by merging the data which was taken from reprocessing of the old seismic data,to depict the main purpose of the layer structure and sand body distribution characteristics.Then,on the basis of analysis and summary of seismic reflection characteristics of main target strata Chang 7 member,by using the attribute intersection analysis,petrophysical analysis and pre-stack inversion technology to further fine depicts thickness and distribution of reservoir.And actively explore the use of pre-stack parameters to predict Chang 7 member tight oil reservoir brittleness index.Using seismic and geological research to delineate tight oil dessert.Through the application of new technology,new method above,achieved six results which provide a basis for well deployment.Based on the above analysis,for Chang 7 member,five tight oil dessert of Chang 7₂ member has been described which covered a total areas of 388.3km² by comprehensive evaluation.Two advantageous areas of I is 318.8km².Three advantageous areas of II is 153.79km².It laid the foundation for the next step to carry out the fine exploration and evaluation in the study area.