Development of Detection Techniques for Monitoring and Optimizing Biocide Dosing in Seawater Flooding Systems

Anaerobic microorganisms which are frequently associated with corrosion fail Control of bacterial activity are posing major challenge in Saudi Arabia’s massive seawater flooding systems. Biocides are used to control bacteria throughout the oil industry. A study to explore the feasibility to develop a detection technique for biocide batch treatments, preferably on-line and in real time, for their potential use in seawater flooding system network is described. Several methods to measure key components of the biocide composition were investigated in the initial stage. Three different techniques were explored during the feasibility phase study to detect and measure concentrations of biocide in seawater. This helped our plans for designing a sensor based on such detection techniques. The techniques explored were to monitor change in temperature, change in pH, and change in chromophore concentration (colorimetric) in the enzymatic reaction. The investigated methods included the use of acetylcholine esterase, based on the pH change as a result of acetate formation, the production of reaction heat (thermal) or on the colorimetric detection of the chromophore concentration based on the conversion of acetylthiocholine in combination with a chromophore. It was found that the colorimetric system was the most versatile system to perform the measurement to be able to show the feasibility of the method in real sea water samples and to demonstrate the effects of the biocides on the measurement system.