A flow-conditioning system includes a pump, process tubing coupling the pump to a source of multiple component process fluid, and an in-line flow-mixing device positioned in the process tubing upstream of the pump. A system includes a well disposed below a body of water and providing a source of multiple component fluid, a pump disposed in and exposed to the water, process tubing coupling the pump to the well, and an in-line flow-mixing device positioned in the process tubing upstream of the pump.