Page 44: of Offshore Engineer Magazine (Jun/Jul 2013)

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(for example with changing water cut, or wells being brought on or taken off line) dosage may need to be modifed to remain optimal.

A tool, which determines optimum

Flowlines dose onsite, would be advantageous.

The result would be improved integrity management, potential chemical sav- ings, and potential benefts for oil—in- water separation, given the surfactant nature of the inhibitors.

The science

Reports have demonstrated a link between the critical micelle concentra- tion (CMC) of surfactant-type corrosion inhibitors and the inhibitory effect.

Real time

Below the CMC, the flm consists of a non-continuous surface, which can be penetrated and allow corrosion to occur. micelle detection

Above the CMC, the flm is denser and multi-layers can form. There is a signifcant drop in increasing inhibitor in development performance at concentrations above the CMC, and so in most circumstances

An additional tool for corrosion management: it can be thought of as the optimal dose the power of corrosion inhibitor micelle detection.

of corrosion inhibitor.

anagement of internal corrosion identifcation of suitable chemicals and

Research Program

M typically involves monitoring a provide data on dosage. LUX Assure has worked with a major number of properties of a system with, In the feld, this dosage may then North Sea operator since 2009 to for example, coupon testing, residual be checked with residual monitoring, develop a corrosion inhibitor micelle inhibitor monitoring, corrosion rate which determines the amount of a detector that could be used in the feld probes, and intelligent pigs. formulation component in a sample of to generate near real-time data. The

One important component of corro- fuid. Yet conditions in the feld may result of this project, CoMic, is a novel sion management is the use of corro- differ signifcantly from those that can tool to improve corrosion management, sion inhibitors, which help protect be set up in the laboratory, for example which has been deployed at UK assets infrastructure. with regard to pressure, temperature, and further afeld to improve corrosion

Organic flm-forming corrosion and the complex mix of treatment management. inhibitors, the type of inhibitor com- chemicals, solids, oil, and water.

Case Study: monly used in the upstream oil and gas Furthermore, when systems change industry, are unlikely to maintain their Production fuids may be transported association with the metal surface for a between different platforms to most very long time as they suffer physical effciently process them. These fow forces from fuid fow. lines can be susceptible to corrosion

Rather, the flm is constantly being and must be managed accordingly. In broken and must therefore be replen- this example, the operator of a feld in ished by inhibitor from the bulk solu- the North Sea had received conficting tion. It is important that an adequate information from traditional methods bulk concentration is present to ensure about the effcacy of the corrosion that the flm integrity is maintained. inhibitor dose.

However, what represents an ad- Two corrosion detection methods equate bulk concentration and how can were being used one of which sug- this be monitored? Often the chemical gested adequate protection at the pipe- dosage is determined from laboratory line exit and one which did not. The testing. Such testing can help in the corrosion inhibitor micelle detection

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