METHOD FOR AUTOMATIC CONTROL OF LOW-TEMPERATURE GAS SEPARATION AT OIL AND GAS CONDENSATE FIELDS IN THE NORTH OF THE RUSSIAN FEDERATION Russian patent published in 2021 - IPC E21B43/34 F17D3/01 

FIELD: oil and gas industry.

SUBSTANCE: claimed method for automatic control of low-temperature gas separation in oil and gas condensate fields in the north of the Russian Federation. The method includes primary cleaning in the separator of the first stage of separation of the produced gas-condensate mixture from mechanical impurities, an aqueous solution of an inhibitor - ASI and heavy hydrocarbons of unstable gas condensate - UGC, which, as they accumulate in the lower part of this separator, are diverted to a liquid separator - LS for its separation into components and degassing. The weathering gas is disposed of. ASI is sent for regeneration. UGC is fed with the help of a pumping unit to the main condensate pipeline - MCP. The purified gas-condensate mixture at the outlet of the separator of the first separation stage is divided into two streams. One stream is fed to the inlet of the first section of the recuperative heat exchanger - HE "gas-gas". The second flow through the valve-regulator - VR is directed to the inlet of the first section of the "gas-condensate" HE. At the exit from the first sections of these HE, the flows are combined and the combined flow is fed through the reducing choke into the low-temperature separator, in which the final separation of the dried gas from the ASI and UGC solution is carried out, which, as it accumulates in the lower part of the low-temperature separator, is sent to the VR through the second section "gas-condensate" HE, providing cooling of the flow of the produced gas-liquid mixture passing through its first section. The dried gas from the outlet of the low-temperature separator through the second section of the "gas-gas" HE is fed for cold recovery to the second flow of the produced gas-liquid mixture passing through the first section of the same HE. Then it is sent to the main gas pipeline – MGP. A VR controlled by a proportional-integral-differentiating - PID controller is installed, which is built on the basis of an automated process control system of the installation, on the bypass line of the second section of the "gas-gas" HE. The input of this PID controller and the PID controller, which controls the distribution of the produced gas-liquid mixture between the first sections of the gas-gas and gas-condensate HE, is fed a single value of the temperature setpoint signal in the low-temperature gas separator, which must the current operating conditions of the field in a given range, and at the same time a signal from the temperature sensor in the low-temperature separator is fed to the feedback input of the same PID controllers. By processing these signals, these PID controllers generate control signals for their VRs at their outputs. The amount of dried gas passing through the bypass line of the second section of the "gas-to-gas" HE, and the flows of the produced gas-condensate mixture passing through the first sections of the "gas-gas" and "gas-condensate" HE are controlled, and thus the temperature is kept in the low-temperature separator in a predetermined range, and at the same time control the temperature value of the dried gas entering the MGP and the temperature of the UGC supplied to the MCP. All these operations are performed using the APCS.

EFFECT: invention increases the efficiency of the process of preparing natural gas and STC for long-distance transport with the optimization of the use of reservoir energy for the process of low-temperature gas separation and improving the quality of prepared products supplied to consumers.

2 cl, 2 dwg