Research On Sedimentary Faces And Reservoir Characteristics Of Chang 4+5 Reservoir In Zengcha Area,Ordos Basin

On the basis of systematic research and further recognition of the description of reservoir characteristic and other theoretical knowledge,the thesis chose Triassic Chang4+5 reservoir in Zengcha area as a subject to study.The sedimentary Faces and reservoir characteristics of it was studied based on drilling,logging and analytical laboratory data,and realize the effective reservoir classification and evaluation.We also introduced “Datis” developed by Chang'an University Digital Oilfield Institute and reduced the workload for data more than 60%.The results of comprehensive research show that Chang4+5 reservoir in Zengcha area is a delta front subfacies sedimentary facies,which is mainly composed of two types of microfacies: subaqueous distributary channel and distributary bay.The rock types are mainly fine grained feldspar sandstone and lithic feldspar sandstone,followed by feldspathic lithic fine siltstone.The porosity is mainly distributed from 7% to 10%,and the permeability is mainly distributed from 0.16×10-3?m2 to 0.7×10-3?m2.The pore structure is complex,and the pore types are mainly intergranular pores and dissolution pores.The throat type is mainly composed of lamellar throat and bundle throat.Through the study of Chang 4+5 reservoir comprehensive application and analysis of all data,the lower limit value of Chang 4+5 effective reservoir in Zengcha area was determined.And we established the classification standard of the reservoir,which is divided into I,II and III three kinds,respectively represents good,ordinary and poor reservoir.Reservoir I accounted for about 10.7%,reservoirs II accounted for 65.3%,and reservoir III accounted for16.5%.It provides an important basis for the exploration and development of this area.