General Hydrate Formation Temperature Model for CO2, H2S, Pure Hydrocarbon Gases, and Sweet and Sour Gas Mixtures with or without Common Salts and Organic Inhibitors.

Gas hydrate formation conditions are a critical problem in the production, processing, and transportation of natural gases. The precise determination of the hydrate formation pressure and temperature is essential. The experimental determination of hydrate formation pressure and temperature is a time-consuming and costly process. Therefore, many published mathematical and thermodynamic models exist to estimate the hydrate formation temperature (HFT). However, most of these models lack generalization, exhibit low accuracy, and have limited application to complex gas systems, including gas hydrate formers and nonhydrocarbon gases without mixed salts and organic inhibitors. This paper presents a generalized HFT model for CO2, H2S, pure hydrocarbon gases, sweet gas mixtures, and sour gas mixtures in the presence or absence of different salts and organic inhibitors (NaCl, MgCl2, KCl, methanol, acetone, ethylene glycol, isopropyl alcohol, 2-pyrrolidone formamide, and N,N-dimethylformamide) using alternating conditional expectation (ACE) algorithms. The blind test of the new model yielded a perfect match with the measured HFT and demonstrated superiority over earlier HFT-published models for hydrocarbon gases, sweet gas mixtures, and sour gas mixtures.