Laboratory assessment of corrosion inhibitors effectiveness at oilfield pipelines of West Siberian region. III. Bubble test

Abstract

This article continues a series of publications dedicated to lab assessment of carbon dioxide corrosion inhibitors efficiency at the oilfield pipelines of West Siberian region. Results of the bubble test are reviewed. The effect of temperature, test duration, condition of the specimen surface, the presence of a hydrocarbon phase, and concentration of inhibitors on corrosion rate and protective properties of a wide range of commercial inhibitors are analyzed. Recommendations on specific test conditions to assess the applicability of inhibitors for protection of water lines and oil pipelines with low watercut are given. The bubble test is a popular method for assessment of corrosion inhibitors used at oilfield pipelines [1][2][3][4][5]. It is characterized by low shear stresses and simulates the corrosion situation not to the full extent even at water lines and oil pipelines with low watercut where the fluid flow velocity is small [5]. However in many cases, this method can allow one to get familiar with the numerous commercial chemicals and to reject the worst efficient ones among them. The purpose of this paper is to assess the capability of this method in ranking of carbon-dioxide corrosion inhibitors for the West Siberian region and determine the test conditions that ensure the most accurate results. We addressed these tasks using the same commercial inhibitors as in [6] as examples. The numbering of inhibitors used in that study was also kept unchanged. Inhibitors No. 3, 4, and 7 are qualified by the manufacturers as imidazolines and No. 5 as a quaternary ammonium base. Inhibitor No. 1 is a mixture of quaternary ammonium bases and imidazoline derivatives. Inhibitors No. 2 and 6 are likely to be amines. Key words: corrosion inhibitors, test methods, oilfield pipelines. ExperimentalDuring the tests, we measured the corrosion rate (K) of steel electrode sensors (by the linear polarization resistance method, LPR) and flat steel specimens (by the mass loss method) placed in the test fluids through which carbon dioxide was slowly bubbled.

On penetration of the migrating corrosion inhibitor IFKhAN-80 into cement stone

“…Inhibitors are very important for the protection of metals from corrosion [1][2][3]. They are widely used to protect reinforced concrete structures.…”

Laboratory assessment of the efficiency of corrosion inhibitors at oilfield pipelines of the West Siberia region IV. Tests in a flow recirculation loop

“…In our point of view, such testing is a mandatory stage in inhibitor selection for their piloting in real pipelines. The purpose of this paper is to assess the capability of this method in ranking of carbon-dioxide corrosion inhibitors and define the test conditions that precisely simulate the conditions of oilfield pipeline operation which are critical in terms of the failure rate.Like in [2,3], these tasks were addressed using commercial inhibitors as examples. At the same time, we have kept the previously accepted numeration.…”

“…Like in [2,3], these tasks were addressed using commercial inhibitors as examples. At the same time, we have kept the previously accepted numeration.…”