Jet pumping basics
In a jet pump lifting system, a power fluid—typically oil or water produced from the reservoir—is pressurized and pumped down the well via a surface pump. The power fluid travels through the downhole jet pump, which is equipped with a nozzle, throat and diffuser. Power fluid flows through this nozzle to create a low-pressure jet core at the end of the nozzle. The low pressure draws reservoir fluid into the pump intake, and the jet core drags reservoir fluids into the throat or “mixing tube,” where the two streams of fluid combine and momentum transfer takes place. The mixed homogenous flow then transfers to the pump diffuser, where static pressure is increased to raise the combined fluids to the surface.

With no moving parts and a compact, durable design, jet pumps have a reputation for reliability and long runlives. Pumps are deployed without a rig simply by using pressurized fluid to set the pump downhole. Redirecting the flow of the power fluid brings the jet pump back up the wellbore for easy retrieval. Recovery of a gas-lift system or ESP typically requires a workover rig.

A common drawback cited with jet pumps is their relative energy inefficiency. It is true that jet pumps commonly run at 20% to 30% efficiency—which means that only 20% to 30% of the total power supplied goes to lifting fluids out of the well—vs. other forms of lift that operate at 30% to 50% energy efficiency. But its other operational benefits, like low installation costs, ease of retrieval and repair, high reliability, low downtime, and tolerance to sand and gas production, combine to make jet pumps a dependable and economical solution for offshore wells. These benefits also enable hydraulic jet pumps to work where other artificial lift systems cannot.