Old well tubing and casing, cement ring, etc. in the process of commissioning, due to the quality of cementing, extraction and injection of alternating loads, medium corrosion and other factors, there will be many forms of damage, which in turn will have an impact on the integrity of the well, and the testing and evaluation of the quality of the casing and cement ring is an important guarantee for the construction of the gas storage reservoir. Based on all kinds of testing data and detailed explanations, this paper scientifically evaluates the residual strength and life of the oil casing in different situations according to the calculation and evaluation methods, processes and bases in the relevant standards, and combined with the working conditions of the wells, historical testing data and so on. It was found that the maximum extension of the specified service life of wellhead devices and wellhead equipment for oil wells is 50% of the service life stated in the specification of the equipment; the permissible internal pressure strength of Φ177.8 mm production casing is calculated to be 45.0 MPa, and the external pressure strength to be 29.15 MPa, which is necessary for determining the safe operating conditions of the production casing; the maximum metal damage rate is 0.1 mm/year; the remaining service life of Φ177.8 mm production casing “xx-6–1 well” is 10 years. When the maximum metal damage rate is 0.1 mm/year, the remaining life of Φ177.8 mm production casing “xx-6–1 well” is 10 years. This paper clarifies the calculation and evaluation method of gas well durability and remaining life for the first time, which makes up for the shortage of this calculation and evaluation method in China, and provides theoretical guidance for the construction of domestic gas storage reservoirs.