METHOD FOR AUTOMATIC LOAD DISTRIBUTION BETWEEN LOW-TEMPERATURE GAS SEPARATION LINES AT GAS TREATMENT PLANTS USING AIR COOLING UNITS, OIL AND GAS CONDENSATE FIELDS OF NORTHERN RUSSIA

摘要

FIELD: oil, gas and coke-chemical industries.;SUBSTANCE: invention relates to the field of extraction and preparation of natural gas for long-distance transportation at complex gas treatment plants (CGTP) of oil and gas condensate fields (OGCF) of Northern Russia. Proposed method includes control of a number of parameters by means of an automated process control system (APCS) of the CGTP. Among them is the flow of dried gas supplied to the main gas pipeline (MGP) and the flow of unstable gas condensate (UGC) supplied to the main condensate line (MCL). APCS maintains temperature of gas separation in each low-temperature separator and controls mode of its operation at specified value of gas flow therefrom. APCS, having received the task on production volume of CGTP UGC, executes it by means of PID-regulator of flow rate maintenance of UGC in MCL, implemented on the basis of APCS. At the SP input, this proportional-integral-derivative controller (PID) controller of the APCS PID controller controls the dispatcher setting signal, and at the same time to its feedback input the PV signals the current flow rate of the UGC to the MCL. Comparing the setpoint and current flow rate of the UGC, this PID controller generates a CV at its output CV, which sends the PID regulators of all process lines (PL) of low-temperature separation (LTS) of the gas, which are also implemented on the basis of APCS. To the PV feedback input of these PID-controllers APCS transmits the signal of actual flow of dried gas to CGTP. Also, at the input of CV of PID-controllers of each LTS TL, a signal of the coefficient of the proportionality factor C_{p_i}, (where i is the LTS TL number), which determines the degree of action of this PID-controller on the control valve (CV) of the gas flow rate through it LTS TL. Value of the coefficient of proportionality C_{p_i} is determined for each LTS TL by its proportionality coefficient calculation unit depending on the cooling capacity of its air cooling apparatus (ACA), installed after separator of first stage of separation, and its operation is controlled by individual automatic control system - ACS. At that, ACS in accordance with APCS task, which is generated taking into account current process parameters in each low-temperature separator and state of environment, controls cooling capacity of ACA gas and sends its corresponding signal to unit for calculation of coefficient of proportionality of its LTS TL.;EFFECT: use of said method enables to provide a given degree of extraction of UGC from natural gas to CGTP at stages of constant, falling and final stages of operation of OGCF at compliance with norms and restrictions on process technological parameters, which are set by process procedure of installation.;4 cl, 2 dwg