Baker Hughes Corporation

Baker Hughes, a Ge Compnay, LLC

Wai Yeung Mok

Vladimir Jovancicevic

Paul Hammonds

Carlos M Menendez

Raymond Paul Gill

Marc N Lehmann

Christopher William Bowman

Neil Jonathan Barr

An oxygen scavenger composition is effective in reducing oxygen-induced corrosion in aqueous systems that contain water, oxygen and a significant proportion (at least about 20 wt %) of a glycol, such as monoethylene glycol (MEG). The oxygen scavenger composition contains a sulfite, a transition metal salt, and a stabilizer to enhance the kinetics of oxygen removal (scavenging). The oxygen scavenger composition is particularly suitable when the transition metal salt component includes at least two different transition metals together, such as Ni and Co, or Ni and Mn.

Application of oxygen scavengers to glycol systems

An electrochemical noise method, apparatus and system may be used to estimate and/or calculate parameters of interest related to corrosion rates of an electrically conductive article. The apparatus involves a working electrode (having substantially the same composition of the electrically conductive article), a reference electrode, and a counter electrode in an environment of interest. The working electrode is placed under potentiostatic control. A current transient between the working electrode and the counter electrode is measured. The working electrode is switched to open potential. A potential transient is measured over the duration of a localized corrosion event. The localized corrosion may then be calculated based on the measured potential transient and the current transient.

Quantitative transient analysis of localized corrosion

An electrochemical noise method, apparatus and system calculates parameters of interest related to corrosion rates of an electrically conductive article. The method involves placing a test electrode, a reference electrode, and an auxiliary electrode in an environment of interest; placing the test electrode under potentiostatic control regime for a potential scan; measuring the relationship of current v. potential (polarization resistance, R) of the test electrode relative to the reference electrode during a first period; switching from potentiostatic control to the open circuit potential (OCP) of the test electrode; monitoring the OCP of the test electrode during a second period; determining &#x394;I from the relationship R=&#x394;V/&#x394;I, where &#x394;V is measured over a second period of time; and calculating the localized corrosion from the measured potential and current data.

Quantitative, real time measurements of localized corrosion events

Simultaneous determination of general corrosion and localized corrosion rate measurements is achieved with polarization applied by the electrodes themselves rather than externally applied polarization. Two or more working electrodes may be galvanically coupled. A localized pitting corrosion event on one of the electrodes will lead to a potential transient. The area within the potential transient is measured with the baseline being the initial starting potential. This gives localized corrosion as a function of time. The relationship Rp=&#x394;V/&#x394;I is calculated, where Rp is the polarization resistance of the working electrodes and is a measure of generalized corrosion rate.

General and localized corrosion rate measurements

The invention provides an electrochemical noise method, apparatus and system for estimating parameters of interest related to corrosion rates of an electrically conductive article, the method comprising: placing a working electrode, a reference electrode, and a counter electrode in an environment of interest; measuring potential at open circuit between the working electrode and the reference electrode over time; placing the working electrode under a potentiostatic control; measuring current between the working electrode and the counter electrode for a predetermined period of time, the period of time of measurements may be extended to include a transient event; and estimating the corrosion rate.

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Manchester, United Kingdom

Wai Yeung Mok