System and method for processing flowback fluid

A method for processing flowback fluid, the method comprising the steps of:

• producing a flowback fluid flow from a plurality of wellheads;
• passing said flowback fluid flow to a system comprised of a plurality of first stage separators, a second stage separator, and a plurality of metering devices,
• wherein each first stage separator is in fluid connection to a respective wellhead, each first stage separator being comprised of a first stage tank with a first stage inlet, a primary first stage outlet, and a secondary first stage outlet, said first stage tank having a first stage volume with a first stage gas capacity,
• wherein said second stage separator is in fluid connection with said plurality of first stage separators, said second stage separator being comprised of a second stage tank with a plurality of second stage inlets, a plurality of primary second stage outlets, and a plurality of secondary second stage outlets, said second stage tank having a second stage volume with a second stage gas capacity,
• wherein each metering device is in fluid connection with a respective first stage separator and said second stage separator, each metering device connecting to a respective primary first stage outlet and a respective secondary first stage outlet connected to a corresponding second stage inlet of said second stage separator,
• wherein said first stage volume is less than said second stage volume;
• passing a first release gas phase of said flowback fluid flow through said primary first stage outlet and passing a first de-gassed flowback fluid flow through said secondary first stage outlet to said second stage volume so as to hold said first stage gas capacity constant;
• passing a second release gas phase of said first de-gassed flowback fluid flow through said primary second stage outlet, when said first release gas phase of said flowback fluid flow passes through said primary first stage outlet and when said first de-gassed flowback fluid flow passes through said secondary first stage outlet to said second stage volume so as to decrease said second stage gas capacity;
• measuring said first release gas phase at said primary first stage outlet with a respective metering device;
• measuring said first de-gassed flowback fluid flow at said secondary first stage outlet with said respective metering device;
• collecting said first release gas phase;
• and
• collecting said second release gas phase.