Hydrates in High Inhibitor Concentration Systems

Project 062 (Part 1)

Hydrate inhibitors are commonly used in pipeline operations whenever there are concerns over hydrate formation. Traditionally, the injected hydrate inhibitor has a concentration at or below 50 wt%. Accordingly, the majority of existing data fall within this range. The only exception is Methanol (MeOH), for which data are available for concentrations as high as 85 wt%. As the drilling activities have moved into colder regions in recent years, inhibitors of higher concentrations are required. In addition, injecting concentrated inhibitors at the wellhead carries a potential advantage of eliminating dehydration facilities in downstream operations. Therefore, the industry is demanding data for the conventional inhibitors at higher concentrations. This work is an extension of an existing GPA Project, No. 031, which measures systems with Mono-Ethylene Glycol (MEG) as the inhibitor. In addition to conventional concentration ranges, Project 031 covers the concentration range from 50 % to about 90 wt%.The objectives of this work include: 1) duplicating selected data points from Project 031; 2) extend the scope of measurements to include "impurities" of inhibitors, such as salts, corrosion inhibitors and pH stabilizes. The acquired data, which will be used to develop correlations, for the described hydrate inhibitor systems will benefit gas pipeline operations, especially in cold regions. Specifically, the benefits can be stated as follows: * improved operation and predictability, * improved product quality, * possible reduction/elimination of dehydrating facilities in downstream operations.