Test separator unit
Test separator unit (TSU) serves liquid-gas mixture separation for measuring liquid and gas content during well testing at oil and gas production field.
TSU components content is defined according to well parameters and individual customer’s requests.
Standard TSU composition is the following:
• oil and gas separator;
• metering line for liberated gas;
• metering line for knocked out liquid.
Separator with collecting tank, piping with shutoff valves and instrumentation are installed in production unit with heating, lighting and ventilation systems. Control cabinet is located in equipment module.
A certified flow computer, programmable logic controller, operator terminal are installed inside control cabinet.
Equipment module installation is to be done afield fr om process module.
Gas condensate mixture is fed to separator wh ere it is treated and gas is separated from gas condensate. Treated gas is discharged from the upper separator’s section and fed into gas line to be measured in flow meter. Knocked out condensate is fed to collecting tank. Separator performs medium control inside the tank by means of differential pressure sensor.
Signals from differential pressure sensor are transmitted to control cabinet of equipment module.
Condensate is discharged from collecting tank by means of shutoff and control valve operating at a defined fluid level of a level meter inside collecting tank. Condensate metering is realized at the outlet of the collecting tank.
Pressure difference between collecting tank and outlet collector required for liquid relief from collecting tank is provided by shutoff and control valve.
A by-pass level indicator is designed on a collecting tank, it controls operation of shutoff valve installed on a manifold. It serves to block gas-condensate mixture at the inlet of TSU when reaching condensate emergency level.
In case complete emptying of a tank and piping is required, liquid discharge is foreseen into a closed drain system of an inlet manifold area for CGTU and gas discharge into flare for CGTU.
Check valves are foreseen for flow lines protection from back-pressure.
Safety valves are designed to protect separator and collecting tank. Gas-condensate mixture is discharged via safety valves into Flare, CGTU.
TSU order is based on a data sheet indicating parameters of the well under testing (production rate, pressure, medium chemical content etc.) and customer’s requirements.
An example of ordering line designation for TSU with nominal production rate of 60 000 nm³/h and nominal pressure of 6,3 MPa: БТС-60 000-6,3.