A method of capturing flow discharged from a subsea blowout or oil seep includes lowering a collector from a mobile offshore drilling unit (MODU) onto a seafloor at a location distant from subsea equipment blowing production fluid. A workstring is connected to the collector and an inert gas is injected through the workstring. The collector is landed onto the subsea equipment while maintaining the injection of inert gas. The inert gas injection is halted and a top of the workstring is routed to surface collection equipment, thereby directing the blowing production fluid from the subsea equipment, into the collector, and through the workstring to the MODU.