Complex of production of liquefied natural gas (LNG) with reduced methane emission into the Earth’s atmosphere V.A. Abramova

摘要

FIELD: oil and gas industry.SUBSTANCE: invention relates to development of deep-sea offshore natural gas (NG) deposits, in particular, during development of Arctic Shtokman gas condensate field (SHGCF) by means of offshore production platform of natural gas, which performs dehydration, purification of NG till compliance with GOST 5542 and GOST 27577. Export of LNG of SHGCF is carried out by LNG carriers. Supply of NG cooled in the heat exchanger located on the cofferdam of the offshore platform foundation to the CTP sets for NG cooling to low, cryogenic temperatures, production and supercooling of LNG, arranged on the LNG carrier cofferdam foundations, is carried out by a flexible gas line passing in thickness of sea water, made of sections, conjugated by flange sealed connections with rings in grooves and spherical hinges, conjugated surfaces of which are coated with solid lubricating materials, for example molybdenum disulphide, and sealed on spherical surfaces of hinges. Electric power supply of Stirling cryogenic-gas machines (CGM) is performed by expander-generator sets (EGA) of turbine expanders by means of electric cables of LNG carriers. Reduction of methane emission to the Earth's atmosphere is carried out by reducing the time for reaching the operating mode of Stirling CGM for LNG liquefying for one hour or 10 tons of LNG/hour by switching the Stirling CGM for LNG liquefying to its preliminary nitrogen cooling to the liquefaction temperature of NG minus (162 °C…165 °C).EFFECT: reduction of methane emission to the Earth's atmosphere and saving of LNG in the course of the SHGCF development make the invention the ecological and technical-and-economic effects.1 cl, 6 dwg