At present,the research on the corrosion rate of the oil casing in the wellbore containing CO2/H2S is the current research hot spot in the field of corrosion and protection. In order to accurately study the corrosion situation of the oil casing and predict the corrosion rate,the weight loss method was first adopted to study the corrosion rate under different corrosion time,and the experimental results were fitted. Secondly, combining the research results of this paper with the previous research content,the Table Curve 3D software for multiple regression was used to determine the corrosion rate prediction model.The results show that the corrosion rate decreases continuously with the increase of time.The fitting of the experimental results R2 is 0.989 3,the error is small.The model established by multiple regression can accurately predict the corrosion rate and the error is within 5%,which meets the accuracy requirements,and can lay the foundation for the on⁃site oil and gas well safety evaluation.

In order to realize the efficient development of the oilfield,it is needed to evaluate the productivity of the reservoir. According to the structure of horizontal well, the form of fracture and the distance of fracture, combined with the theory of seepage mechanics, a well test analysis model for multistage fractured horizontal wells considering wellbore storage and skin factor is established. A typical curve fitting chart of pressure and derivative is obtained, and a well testing interpretation software system based on the theoretical plate is developed. Based on the well test interpretation software system compiled by the theoretical plate, the IPR curve and the production decline curve are plotted by using multistage fracturing horizontal well test interpretation software.The results show that under the same production conditions, the influence of fracture distance and crack skin factor on productivity is less than the effect of crack half length on productivity. According to the curve of production flow rate with bottomhole flow at different production stages and the curve of output with production time at different bottomhole flow pressures, and the production capacity is predicted and evaluated at different stages of fracturing horizontal wells. It provides a strong guarantee for the efficient development of multistage fracturing horizontal wells.