EVALUATION OF CORROSION INHIBITORS EFFECTIVENESS IN OILFIELD PRODUCTION OPERATIONS

It is known that corrosion is a natural process and is impossible to prevent completely. Thus we only try to control corrosion. Even though coatings and cathodic protection are often more effective chemical inhibitors are also widely used to reduce corrosion particularly in gas wells producing CO2 H2S and water. The effectiveness of the inhibitor and compatibility with produced fluids must be tested in the laboratory. Inhibitor film efficiency depends on the inhibitor concentration and contact time with the metal surface. A compact and relatively inexpensive system called High Speed Autoclave Test HSAT was used with corrosive gases such as H2S and CO2. Using this system the effectiveness of inhibitor was evaluated and all the variables that influences corrosion rate were easily controlled in the laboratory in order to predict field corrosion rates. Several inhibitors were evaluated active ingredients of those inhibitors include long chain amines amides and imidazoline est inhibitors were tested at the concentration range of 500-10000ppm in a mixture of brinehydrocarbon in the presence of H2S and CO2. In the experimental investigation results showed that inhibitor D imidazoline surfactant was the most efficient 92 at 1000ppm.