Reservoir Evaluation Of The Chang 2 Member Of Yanchang Formation In Block XX Of Jingbian Oil Field

The research area is located in the south of jingbian county,yulin city,shaanxi province,covering an area of 22.58km².In this paper,the use of logging data,core data,thin section identification,scanning electron microscopy,on the basis of test and analysis methods,such as in structural geology,petroleum geology,sedimentary petrology and other disciplines theory as the instruction,the detailed description and classification evaluation of the cahng2¹ section of the Yanchang Formation in the study area was completed,which provided a certain theoretical basis for the future development of the area.The study shows that the study area drilled to the bottom of chang 2¹,chang 2^1-1 and chang 2^1-2 are favorable reservoirs in the study area.The study area is located in the middle of the Ordos Basin.The overall structure is a west dipping monocline,the strata are relatively gentle,and some low and slow nasal uplift is developed locally.The study area are mainly delta plain subfacies deposition,the branching river and marsh depression as the main sedimentary microfacies,controlling the development of the reservoir in the study area,lithology mainly feldspar sandstone,low compositional maturity,the content of the filler content is less,more rounded for subangular,sorting,maturity structure of medium-good,with primary intergranular pore and feldspar intragranular dissolved pore as the main reservoir space,throat to flake or curved sheet,tube bundle throat.With an average porosity of 16.01%and an average permeability of 10.96×10^-3?m²,the chang2¹ reservoir is a middle porosity and low permeability reservoir.Based on the characteristics of sedimentary facies,physical properties and pore structure,this paper has worked out the classification criteria suitable for chang2 reservoir in this area.The chang 2¹ reservoir in the study area is divided into four types of reservoirs,which are good reservoirs of class I,good reservoirs of class II,general reservoirs of class III and poor reservoirs of class IV.Class I and II reservoirs are the majority of the chang2^1-1 reservoirs,followed by class III reservoirs.The distribution range of class IV reservoirs is small.Chang2^1-2 reservoir has the largest area of class III reservoir,followed by class IV reservoir and class II reservoir.The development area of class I reservoir is very small.