Study On The Sacrificial Anode Protection Technology About High PH Value And Gas Well With High Sulfur Content

Hydrogen sulfide and carbon dioxide in the production of gas field with high sulfur content make ring empty corrosive environment more terrible. In order to avoid the damage of corrosion, extend the service life of tube and casing, meet the actual demand of long-periodic stationary, we usually use protection fluid to protect ring empty corrosive environment.In order to prevent protection fluid from corroding tube and casing and extend the service life of tube and casing, we use the technology of sacrificial anode protection. however, there are many problems of using conventional sacrificial anode in the production environment, such as:1) Conventional sacrificial anode current efficiency is low because of strong corrosive and high temperature;2) Due to the effect of corrosion, traditional sacrificial anode generated a layer of sediment and anticathode surface in the reaction with the media after surface corrosion, which hinder further work;3) Normal sacrificial anode is used in acid medium.We are aimed at inventing two kinds of new sacrificial anode that can be used in protection fluid. Because protection fluid has different pH value(pH=7-9, pH=9.5-11). We use aluminum alloy anode as research object in the selection of anode. Because aluminum alloy anode has small density and large electrochemical equivalent. We add some element in aluminum alloy, which could improve the electrochemistry performance of aluminum alloy anode and enhance the current efficiency of aluminum alloy anode under high temperature environment. We select sacrificial anode which has good electrochemistry performance in protection fluid(pH=7-9) under 80℃. We also optimize the parameter of well chamber protection craft, which provides the basis for designing the well chamber protection. We select R4 as sacrificial anode in protection fluid(pH=9.5-11), which open-circuit potential is -1.069V in the protection fluid under 80℃, work potential is-0.939~-0.996V and current efficiency is 87.65%. We should develop the technology of sacrificial anode protection, which makes significance for the safe and efficient development of gas field with high sulfur content.