METHOD FOR AUTOMATIC MAINTENANCE OF DENSITY OF UNSTABLE GAS CONDENSATE SUPPLIED TO MAIN CONDENSATE LINE, USING TURBOEXPANDER UNIT, IN INSTALLATIONS OF LOW-TEMPERATURE GAS SEPARATION IN AREAS OF EXTREME NORTH Russian patent published in 2019 - IPC F17D5/00 

FIELD: technological processes.

SUBSTANCE: invention relates to the field of production and preparation of gas and gas condensate for long-distance transport. Proposed method comprises purification of incoming gas-condensate mix coming from production wells from mechanical admixtures in separator of first stage of separation. At the plant gas-condensate mixture is divided into UGC, gas and aqueous solution of inhibitor (ASI), with subsequent removal UGC and ASI into separator of liquids for degassing. From separator of liquids ASI is withdrawn for regeneration of inhibitor in inhibitor regeneration shop, and UGC pump is fed into manifold condensate line (MCL). Weathering gas from liquid separator is sent for use for own needs, for compression with subsequent pumping into main gas line or for recycling. To control density UGC APCS monitoring density sensor density UGC, supplied to MCL. Simultaneously APCS temperature sensor controls the temperature of the gas at the outlet of the low-temperature separator, the value of which is automatically maintained by controlling the rotational speed of the turbine expander (TDA), which is set by cascade of two proportional-integral-differentiating (PID) of regulators implemented based on APCS plant. To this end, the SP input PID-density maintenance regulator UGC at fluid separator output density setting signal is transmitted UGC, which value is set by maintenance personnel. And to feedback input PV of same PID-controller transmits actual density signal UGC from sensor installed at fluid separator outlet. Comparing said signals, PID-regulator generates at its output CV a rotor rpm setting signal TDA, providing required cooling of gas-liquid mixture supplied to input of low-temperature separator, and ensuring achievement of required density UGC at fluid separator outlet. Setpoint signal APCS sends SP input to input PID-rotor speed control regulator TDA. Simultaneously, to feedback input PV of this PID-regulator, from rotor rpm sensor TDA, rotor actual rpm signal is supplied TDA. Comparing input signals, PID-rotor speed control device TDA generates at its output CV control signal of control valve installed at output from turbine TDA. Due to this, control over the volume of dried gas leaving the low-temperature separator and passing through the compressor TDA. At that, APCS simultaneously controls and pressure in separator of liquids, automatically maintaining its value specified by process procedure of installation, by means of control valve installed at gas outlet from separator of liquids.

EFFECT: disclosed method enables automatic monitoring and maintaining a given density UGC, supplied to MCL, prevent formation of gas plugs and their accumulations in condensate line, reduced risk of occurrence of emergencies during operation MCL, associated with density fluctuations UGC.

1 cl, 2 dwg