Podcast: How Does a 3-Phase Separator Work? Episode #5

How does a 3-phase separator work? In this episode, Kimray Product Applications Trainer Kyle Andrews explains.

Topics for How Does a 3-Phase Separator Work?

  • Why is separation so critical in oil and gas production?
  • What are the 3 phases?
  • Where are these types of separators found?
  • What are the key components of a separator?
  • How does a 3-phase separator work?
  • What type of controllers do 3-phase separators require?

Resources mentioned in this episode:


three-phase separator podcast3-Phase Separator podcastpodcast 3 phase separator oil and gas


Curtis: Welcome to the Stuff You Should Know About Oil and Gas podcast. My name is Curtis Winkle and I’m here with Kyle Andrews, who is our product and applications trainer. How are you, Kyle?

Kyle: I’m doing pretty good.

Curtis: Great. Today we’re going to talk about three-phase separators, what they are, how they work, why, why we use them. So Kyle, first of all, just tell us what is a separator?

Kyle: A separator is exactly what it sounds like. It separates things. Now what are we separating? When a well is drilled, the product that’s coming out of the ground is not sellable.

It’s a mixture of oil, gas, and water and some other things. So it’s all mixed together. It’s worth nothing that there are a lot of things that happen in between it coming out of the ground and when you put it in your car, and the first step is separation.

Curtis: You mentioned oil, water, and gas. Is that why they’re called three-phase separators?

Kyle: It is. So three phases could mean could mean any three things that you’re separating. In the oil and gas industry, when people say three phase, what they’re talking about is oil, gas, and water.

Curtis: So where in the process are these used, is it usually pretty early on? Upstream, right?

Kyle: The majority, yes, but there are different kinds of separators, different processes that use separation. Really you can find them across all three sectors of the oil and gas industry. In the upstream, midstream and downstream, all use it for slightly different reasons.

The upstream sector would use it for the initial separation, to separate the products before they’re sold. Midstream uses it because their processes require a separation to happen as they’re moving gas or as they’re moving a liquid. As the conditions that those resources are exposed to change, they requires further separation.

Downstream, depending on what product they’re trying to turn it into, they could need to separate out certain elements from those resources to get the final product.

Curtis: So many different things come from what we’re pulling out of the ground.

Kyle: Yeah.

Curtis:  How does a 3-phase separator work? What’s going on inside that separator?

Kyle: After the emulsion, which is the water, gas and oil mixture, comes out of the ground, a separator is one of the first pieces of equipment it’ll go into. There are different designs internally and externally, but at its basic, it’ll come in and hit a diverter plate, which is basically a plate welded in the interior of the vessel, and the flow comes in and hits that diverter plate and that sudden impact really starts the separation process.

The gas will begin to break out of the liquid, and as the liquid goes into the vessel and sits there for a while, which we call retention time, the difference in specific gravities between the different fluids will cause it to start to separate out.

Think of it like your salad dressing. Keep it in your refrigerator and it sits there for a while, the vinegar and the oil separate out and you have to shake it up.

So if you give something enough time and it has differing specific gravities, it’ll start to separate out on its own. So that’s really what a separator is doing, just giving it retention time.

And also there’s mechanical means to help that separation get going.

Curtis: Yeah, I know we’ve got some great visuals on the website of just some oil and water sitting in a jar and a time lapse of what it looks like as it separates because of the gravity difference.

Kyle: Yeah. It’s a good visual to have, and watching a time lapse is a lot faster than watching your salad dressing.

Curtis: Right. So how do we control the separator? What controllers do you need on it to make the separation happen and to flow it from one place to another?

Kyle: Besides the separator itself, you’re going to have a back pressure regulator, and that’s to hold pressure on the vessel, to help move liquids from this place further downstream to either another separator or just the next process downstream, and then dump valves.

Dump valves are where that fluid is exiting. The oil will go through the oil dump valve, water through the water dump valve. And then level controllers.

There are different types of dump valves and level controllers, but they’re all needed. Some version of them is needed on a separator to make it work.

Curtis: How about the different types of separators? I know there are horizontal and vertical separators and probably different pressures as well.

Kyle: If you want to take separators as a whole there’s tons and tons of different separators. You mentioned horizontal, vertical, there are heater treaters, filter separators, a number of types. Really pretty much every piece of equipment that resources go into after they come out of the ground is some type of separator.

Curtis: That’s the old joke: Everything’s a separator. All right. So in terms of the these horizontal and vertical separators, what are the advantages of them. Even though this is kind of an umbrella term, how about the advantages of a horizontal, a vertical and then a heater treater?

Kyle: With a horizontal separator, you can move higher volumes of fluid. They are bigger, they take up more ground space, so they have a bigger footprint when compared to vertical.

Vertical separators take up less space and typically they handle slugs of fluid a little bit better than horizontal separators.

Heater treaters are kind of a different beast there. I mean, there’s also horizontal and vertical heater treaters, but the advantage to those is we’re using heat to help aid in the separation process. So it speeds up the separation process, whereas a traditional vertical or horizontal separator doesn’t have heat, it’s relying on those mechanical means of separation and also retention time to separate a heater.

Curtis: So it’s going to advance the process of separation just by adding heat to the process?

Kyle: Correct.

Curtis: Alright, Kyle, appreciate you sharing that. If you want to speak with an expert about your separation processes and how to get the most out of the Kimray products there, you can contact your local Kimray store or authorized distributor, and they’ll be happy to chat with you. We will catch you next time on Stuff You Should Know About Oil and Gas.

Want to receive helpful resources like this directly in your inbox?

Subscribe to the Kimray Chronicle