Natural Gas Hydrate Particles in Oil-Free Systems with Kinetic Inhibition and Slurry Viscosity Reduction

摘要

Petroleum fluids may form hydrate crystals with water at conditions often encountered in nature. Hydrate formation in large pieces is a serious problem in flow assurance and oil capture from the seabed. Use of functionalized molecules in very small quantities offers effective solution through formation of small hydrate particles. The literature suggests water-ki-oil emulsion for hydrate antiagglomeration, which limits the application because of requirement of large amounts of the oil phase. In a recent article, we have demonstrated hydrate antiagglomeration of methane in water and brine by a new surfactant molecule at 0.2 wt % without water-in-oil emulsion. However, in a natural gas containing CO2, the same surfactant loses effectiveness. In this work we offer a revised formulation consisting of the surfactant, small amounts of a base, and an alkane. The base adjusts the pH, and the alkane serves as a defoamer. The effects of each component are systematically discussed in this work, and a synergetic effect is found. The new formulation provides effective antiagglomeration in a broad range of conditions. Moreover, our formulation has three other beneficial effects including kinetic inhibition, reduction of slurry viscosity, and corrosion inhibition.