Research On Sedimentary System Of Shanxi Formation In Yanqi 2 Well Field Of Ordos Basin

In recent years of exploration and development indicates that Shanxi formation was one of the most important zones in mid-eastern Ordos Basin,Yanqi2 area is an important exploration in Yanchang exploration areas.Because the low degree opinion about the gas reservoirs of the east of the upper Paleozoic in the Study area.Therefore,it is very difficult to use of seismic data to study the formation of Shanxi formation in this area.On the basis of previous studies and according to the available exploration data,Comprehensive utilization of logging,seismic and geological data combined approach to discipline stratigraphy,reservoir sedimentology,seismic sedimentology,petroleum geology theory,Based on the Yanqi 2 area of Shanxi formation in stratigraphical correlation and subdivision,seismic facies analysis,sedimentary facies analysis and reserch on depositional system of in Ordos basin was carried out.The research results provide the basis for further exploration and development.The main research contents of this paper are as follows:(1)The stratigraphic division of 17 wells,Shanxi formation of yanqi 2 field was divided into Shan 1?Shan2 and six submembers,And analysis of each sub-segment of sand body distribution analysis.(2)The upper Paleozoic sedimentary system in the study area,Mainly dominated by delta front sub facies,further analysis can be divided into underwater distributary channel,underwater distributary bay,mouth bar,between the bay and marsh microfacies.(3)identify four main seismic facies types: in-phase axis deviation-continuous,variable amplitude phase,phase axis in continuous,weak amplitude and phase,phase axis high continuous,high amplitude facies,filling phase,sedimentary facies plane research provide important basis.(4)The underwater channel is a good reservoir of natural gas,and the distribution of sand bodies in each sub section can be seen.Several sets of thick sand bodies are mainly formed by the multi period river channel,and based on the analysis of sedimentary microfacies and sand body distribution,the depositional model of the study area is drawn and established.