Theoretical and experimental justification of the method for determining the parameters of the moment of gas hydrates mass crystallization

Abstract

The processes of oil and gas production – extraction, preparation, storage and transportation of oil, gas and condensate – are accompanied by risks of man-made hydrate formation. Such man-made gas hydrates cause serious problems for the oil and gas production industry. Oil and gas companies bear significant material costs in connection with the prevention of these processes. For prevent or eliminate it in each specific case, it is necessary to understand the physics of processes and parameters of hydrate formation. Therefore, establishing the peculiarities of the kinetics and thermobaric parameters of the hydrate formation process is an urgent problem. Thus, the object for research is the parameters of the beginning of mass gas hydrates crystallization in reservoir systems. At the same time, the most reliable results can be obtained in the process of laboratory monitoring of processes in reservoir systems and technological equipment directly at industrial facilities.

The process of hydrate formation at the phase boundary is manifested by the formation of a thin hydrate layer in the form of a film. In the course of experimental studies, it was established that this process is visually fixed by the transformation of the mirror surface of the phase boundary into a matte one. The distortion effect of the interphase boundary is explained by the formation, growth, massive and chaotic accumulation of gas hydrate microcrystals at this boundary. In the work, based on the results of theoretical and experimental studies, the methodology for operational laboratory determination of parameters of mass gas hydrate crystallization is substantiated. The essence of the technique is to establish the parameters for the moment of mass gas hydrates crystallization based on the fixation of the optical distortion effect of the reflection of the light source on the mirror of the liquid-gas interphase surface. The results of empirical studies are based on optical phenomena observed at the interfacial surface of the gas hydrate layer and gas. They were studied using microscopy, fixation and image processing methods. The main experiments result was the information recorded by the optical system and obtained after fixing the pressure and temperature.

The technique can be used to establish and operationally control the moment of mass gas hydrates crystallization directly at the objects of the oil and gas industry (during the implementation of technological processes). This will make it possible to effectively prevent clogging of technological equipment with the solid gas hydrate phase, as well as to prevent overuse of hydrate formation inhibitors. At the same time, the only limitation of the application for this technique may be the low light permeability of the aqueous solution as part of the formation system.