Methods to drawdown pipe sections with the use or regulation control of flaring and cross-compression technique

A system for evacuating a drawdown section comprising:

• a separation vessel configured to receive a flow of a gas/liquid mixture from a drawdown section and allow the gas/liquid mixture to separate into a liquid phase and a gas phase within the separation vessel;
• a control valve controllable to flow the gas phase out of the separation vessel towards a flare where it is burned;
• one or more pumps controllable to flow the liquid phase out of the separation vessel to an adjoining section while the control valve is flowing the gas phase towards the flare;
• a liquid level controller configured to perform operations comprising:
• monitoring a liquid level within the separation vessel;
• actuating the control valve to adjust the flow of the gas phase out of the separation vessel;
• and
• adjusting the flow rate of the liquid phase out of the separation vessel by manipulating the discharge rate of the one or more pumps, wherein the actuating of the control valve and the adjusting of the flow rate of the one or more pumps is configured to maintain the liquid level inside the separation vessel at a predetermined level, or between a minimum and a maximum level;
• and
• a gas injection line configured to inject an inert gas into the liquid phase after the liquid phase has flowed through the one or more pumps in an injection flow direction that is opposite to a flow direction of the liquid phase.