Use of alternative energy sources to improve the efficiency of natural gas hydrate technology for gas offshore deposits transportation

Purpose. Justification of the principal schemes acceptable for the existing level of technology, methods of extraction and transportation of offshore natural gas deposits. Increase in their efficiency by maximum reduction of energy consumption resulting from complex considerations of thermal and physical properties and parameters of the system components interaction. The work is focused on the improvement of borehole products preparation system according to the gas hydrate technology during the development of offshore gas fields. The research objects were thermodynamic parameters of the system “gas-water-gas hydrate” in a vertical pipeline under nonadiabatic conditions. Methods. Analysis and generalization of the results obtained from the complex experimental research. Mathematical modeling and software development. Findings. The technology of gas transfer into a gas hydrate form without energy consumption for phase transition was proposed. The expediency of gas deposits development by its binding into the gas hydrate form during passage through the sea layer in the appropriate thermobaric conditions was substantiated. Mechanism of the alternative energy sources use for the production of gas hydrates, as the most energy-consuming process in technology of transpor-ting gases in the form of gas hydrates, was grounded. Originality. The principle possibility of binding the extracted gas into the gas hydrate form due to the energy of the productive layer and salt water was estimated. A mathematical model and software product for the description of the hydrate formation process in the presence of excess water in a vertical pipe under non-adiabatic conditions were developed. Practical implications. The proposed gas hydrate technology creates important prerequisites for the development of small- and medium remote gas deposits, improves the efficiency and competitiveness of technology for marine transportation of natural gas in hydrate form.