High H₂S and CO₂ content, complicated geological condition and field environment brings so many world-classic problems to the exploration and development engineering in Northeast Sichuan gas field. By introduction, research and practice, serial techniques such as drilling, gas test, and completion workover, etc., for the ultra deep and highly acidic gas field were gradually formed. Therefore Puguang Gas Field, for the first time, such reservoir is safely developed in China. This paper introduced these techniques briefly to provide reference for domestic similar gas fields and give many proposals to expand the exploration and development engineering techniques of ultra deep and highly acidic gas field.