Study on Sedimentary Features of Shanxi Formation in Yanchang Oil Region of Ordos Basin

Ordos basin is a large multicyclic craton basin.The lower permian shanxi formation of Yanchang oil region in Ordos basin is a set of paralic coal-bearing series formed in the warm and humid climate conditions which based on the early continental sea regression under the background of Variscan orogeny.Based on Shanxi formation characteristics,petrological characteristics,the provenance analysis and sedimentary characteristics research,in combination with logging,geological data of core and regional exploration achievement,it's found that in Shanxi formation,sedimentary facies of north and south region in Yanchang oil region are mainly delta front and developed underwater distributary channel and underwater distributary bay intrafacies,etc.Underwater distributary channel of delta front is a good sandstone reservoir.