Well hua 49 area in Huachi oil field, Xuanma area, well 63 area, well 55 area in Chenghua region in Shan-gan-ning basin are now produced under natural water drive.
Major sedimentary facies in the Huanhe-Huachi Formation include lacustrine facies, delta facies, meandering fluvial facies, and interbedded eolian sandstone facies.