| Puguang gas field,as the first high sulfur gas field successfully developed in China,has the characteristics of high yield,high pressure,high hydrogen sulfide and deep burial depth of reservoir.The average content of hydrogen sulfide in gas field is 15.16%,the average content of carbon dioxide is 8.64%,and the development of gas reservoirs with such high sour gas content is very little mature experience in the world.The gas field has been in production for 8 years,and the surface gathering and transportation system has experienced many tests such as sour gas,formation residual acid,impurity,condensate water and sulfur deposition,and has already entered the development period of gas reservoir water production.At the same time,due to high corrosion of hydrogen sulfide in the transport medium,the difficulty and risk of gas field development are increased.In this paper,the corrosion status,corrosion reasons and mechanism of the ground gathering and transportation system are analyzed and studied by using corrosion monitoring data,inspection data and maintenance data over the years,and the corrosion law of the ground gathering system is obtained;Then,the risk of water corrosion caused by water quantity,water type change and accumulation of liquid is evaluated and analyzed.The influence of water quantity change on the residual concentration of corrosion inhibitor,the influence of water type change on the corrosion inhibition efficiency and the influence of the pre filming process on the corrosion inhibitor efficiency were studied.On this basis,the optimization scheme of corrosion control in gathering and transportation system of Puguang gas field is put forward.Finally,the feasibility of the optimization scheme is verified by field application analysis.This study for the Puguang gas gathering system to improve the application of corrosion inhibitor injection and control effect,reduce corrosion rate,prolong the service life of equipment and pipes,gas gathering system ensuring safe and stable operation,and reduce the cost of production and management aspects are of great social and economic benefits. |
