METHOD FOR AUTOMATIC LOAD DISTRIBUTION BETWEEN LOW-TEMPERATURE GAS SEPARATION LINES WITH TURBO-EXPANDER UNITS AT GAS TREATMENT FACILITIES OF NORTHERN RUSSIA Russian patent published in 2021 - IPC F17D3/01 

FIELD: mining.

SUBSTANCE: invention relates to production and preparation of natural gas of Valanginian deposits (hereinafter - natural gas) to long-distance transport at complex gas treatment plants (CGTP) of oil and gas condensate fields (OGCF) of Northern Russia. Proposed method comprises monitoring by means of automatic process control system (APCS) of CGTP by a number of parameters. Among them is the flow of dried gas supplied to the main gas pipeline (MGP) and consumption 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 by changing degree of adiabatic expansion of gas with performance of external mechanical work in turboexpander unit (TEU), standing in front of each low-temperature separator. APCS, having received the task by the CGTP UGC production volume, it executes with the help of the proportional-integral-differentiating (PID) regulator the UGC flow rate maintenance in the MCL based on the APCS. At the SP setting input of this PID controller, the APCS sends the dispatcher setting signal, and simultaneously to its feedback input PV supplies the UGC current flow signal to the MCL. Comparing the reference and the current flow rate of the UGC, this PID controller generates, at its output CV, a setting signal which supplies the PID control inputs of the PID regulators of all LTS TL gas to the input of the SP, which are also implemented based on APCS. And to the PV feedback input of these PID-controllers APCS sends a signal of actual flow of dried gas to CGTP -V. 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 individually for each LTS TL by its unit for calculating the proportionality coefficient depending on the speed of rotation of the TEU rotor, which is recorded by the ACS with the help of a rotor rpm sensor. Application of this method allows to ensure the specified degree of UGC extraction from natural gas to CGTP at stages of constant, falling and finishing stages of OGCF operation at compliance with norms and restrictions on process technological parameters, which are set by process procedure of the installation.

EFFECT: preset quality of natural gas and gas condensate treatment for long-distance transport is ensured by taking into account actual condition of CGTP equipment.

4 cl, 2 dwg