Unlocking Engineering Solutions for Handling a Complex Mix of KHI, MEG, Corrosion Inhibitor, and Produced Water

The compatibility of KHI and MEG, chemicals used to inhibit gas-hydrate blockage, with corrosion inhibitors (CI) and produced water is a significant concern in the oil and gas industry. Consequently, pipeline integrity, flow assurance, and safely produced water management are critical. This paper highlights an innovative engineering approach based on extensive lab testing and field study that can resolve a complicated mix of KHI, MEG, CI, and produced water. A field sampling was conducted to assess the severity of the mixing of KHI, MEG, and CI and the water produced in the production stream. The tests were conducted at temperatures 35 and 65 oF to reflect summer and winter operations, including the dissolve tendency. The pressure was constant at 70 psi, and the soaking time was 24 hours. Core flood tests were performed using reservoir core plugs to study the compatibility. The incompatibility of KHI, MEG, CI, and produced water was discovered, and the resultant sludge was found to be soluble in distilled water and HCl acid but insoluble in Xylene and Diesel. The core flood test revealed that adding 1,000 ppm of KHI to water will cause the original core brine permeability to decrease by around 13%. There will be a slight decrease in these mixes when the MEG and CI are added. Injection of nearly 7 pore volumes of 7 wt% NaCl brine was able to remove the created damage. The blending of all chemicals with produced water showed less damage (almost 8%) compared to that of KHI alone. Based on this test, the engineering solution is derived from the segregation of the KHI as soon as possible before mixing it with the rest of the water. Therefore, new pipelines, buffer tanks, transfer pumps, and filtration systems are required.