Field Report | Producer Solves the Oil and Gas Separator Emulsion Mystery

 

Recently, a producer ran into a problem in Catarina, Texas. As the Technical Development Engineer, he was responsible for keeping this field producing smoothly. But it seemed his liquid level controller wasn’t maintaining the proper interface of oil and water.

Oil and gas producers use separator vessels (like the one below) to separate a well stream into gas and liquid. These are typically installed near the wellhead, and come in three styles: horizontal, vertical, or spherical.

Two-phase oil and gas separators separate the emulsion into gas and liquid. Three-phase separators go a step further to break the emulsion into gas, oil, and water. In this case, the producer was using a three-phase separator.

When fluid enters a three-phase oil and gas separator, separation begins naturally, due to the different specific gravities of the elements. The gas rises to the top of the vessel and is released into a gas line for either further processing downstream or combustion. The oil settles at the middle level, and when it reaches a specific height, as determined by the liquid level controller, it will be dumped to the production line and sent downstream to be processed and enter the sales line. The water is also controlled by another level controller, and will be dumped into a separate line and sent to be recirculated or injected.

While this separation process does occur naturally, some producers choose to introduce heat into the vessel, which can accelerate the process.

Oil and gas separator with Kimray Gen II Liquid Level Controller installed.

When the engineer spotted the oil and water emulsion, he closed the ball valve upstream of the separator. He had to stop production and ended up taking his liquid level controller off the vessel. Upon examination, it was clear that the displacer on the level controller was malfunctioning.

A displacer malfunctions when the process fluid doesn’t react well to the material of the displacer. This may be because the specific gravity of the fluid is lighter than the displacer is made for, or because the fluid is so corrosive that it eats through the displacer.

This malfunction was leading to erratic, imprecise dumping of oil and water rather than steady dumping after the appropriate amount of separation occurred.

His first step was to reach out to the original product manufacturer. After running into delays attempting to solve the problem by phone, and growing frustrated due to the downtime, the engineer persisted. With his options exhausted, he contacted his corporate office in Houston to see about replacing the units. The Houston office contacted Kimray’s local team in Corpus Christi for help.

Since the site was running on electric actuation, the Kimray team recommended outfitting the separator with the Gen II Electric Level Controller. Kimray sent certified technicians to the site to install it. After the 1-hour installation, the crew re-opened the ball valve and allowed the vessel to re-fill.

They watched with the Kimray installation team as the displacer rose with fluid, activating the dump valves and processing the fluid correctly. Thanks to the engineer’s persistence, the field was fully operational. Everything was flowing like clockwork. His efforts were rewarded with a fully functional field. The Houston office appreciated that production was only interrupted for a short time. Everyone felt confident that the new equipment ensured productivity for years to come—and that service was right around the corner.