METHOD FOR AUTOMATIC CONTROL OF INHIBITOR SUPPLY TO PREVENT HYDRATE FORMATION IN LOW-TEMPERATURE GAS SEPARATION PLANTS OPERATED IN THE FAR NORTH Russian patent published in 2022 - IPC E21B37/06 F17D3/12 

FIELD: gas industry.

SUBSTANCE: invention relates to preparation of natural gas and gas-condensate mixture for long-distance transport, in particular, to prevention of hydrates formation and destruction of hydrates in low-temperature gas separation units (LTSU). Method includes an automated process control system (APCS), which controls the flow rate of the inhibitor and controls its flow rate using a throttle valve (TV). APCS controls pressure and temperature in separators, concentration of regenerated inhibitor and calculates by these parameters in control system TV setting for supply of required amount of inhibitor and supplies it to points in front of protected areas. At the same time, APCS controls flow rate of gas-condensate mixture at the inlet and outlet of the separator of the first separation stage, temperature and pressure of the gas-condensate mixture in the inlet line of LTSU, in the separator of the first separation stage, intermediate and low-temperature separator. APCS also controls the concentration of the inhibitor in the aqueous solution at the outlet of the liquid separators of the first separation stage, the intermediate and low-temperature separator, the concentration of the regenerated inhibitor supplied to all protected sections of the LTSU, and performs individual control of its flow rate at each input point. From 60 % to 80 % of the calculated value of the regenerated methanol is supplied to the injection points located at the beginning of the well clusters in proportion to their gas condensate mixture production capacity, and from 40 % to 20 % of the calculated value of the recovered methanol to the point of its inlet into the line after the first stage separator. Exact ratio of the supply of regenerated methanol to the input points of each specific gas-producing complex is determined based on the results of a full-scale experiment, which is carried out at least once a year.

EFFECT: inhibitor consumption is optimized to prevent hydrate formation and LTSU operation mode is efficiently organized.

1 cl, 1 dwg