Multiphase production boost method and system

A method for boosting a pressure of a low-pressure multiphase mixture to a high-pressure multiphase mixture, the method comprising the steps of:

• introducing the low-pressure multiphase mixture into a pressure boost system, where the low-pressure multiphase mixture comprises a low-pressure liquid an a low-pressure gas;
• operating the pressure boost system such that
• the low-pressure liquid and the low-pressure gas form from the low-pressure multiphase mixture within a gas-liquid separator,
• a high-pressure liquid forms from the low-pressure liquid by a liquids pump that couples to a liquid portion of the gas-liquid separator,
• during a charging period the low-pressure gas is introduced into and the low-pressure liquid passes from a liquid piston compressor,
• during a compression period a high-pressure liquid is introduced into the liquid piston compressor such that the low-pressure gas converts into a high-pressure gas,
• during a discharging period the high-pressure liquid is introduced into and the high-pressure gas passes from the liquid piston compressor,
• a gas portion of the liquid piston compressor couples to a production line such that there is one-way fluid communication of high-pressure gas from the liquid piston compressor to the production line, and
• the liquids pump couples to the production line such that there is communication of the high-pressure liquid from the liquids pump to the production line that bypasses the liquid piston compressor,
• the high-pressure liquid and the high-pressure gas are mixed such that the high-pressure multiphase mixture forms;
• cooling the liquid piston compressor with a cooling system having an inlet head at a first end of the liquid piston compressor, an outlet head at an opposite end of the liquid piston compressor, and a shell fluid void located between the inlet head and the outlet head and within the liquid piston compressor, where the inlet head is in fluid communication with the liquid portion of the gas-liquid separator by way of a cooling liquid feed line and the outlet head is in direct fluid communication with the gas-liquid separator by way of a return line, where the low-pressure liquid passes through the cooling liquid feed line and returns to the gas-liquid separator to mix with the low-pressure multiphase mixture being introduced into the pressure boost system;
• and
• passing the high-pressure multiphase mixture from the pressure boost system.