In the fifth of a series of episodes, Pipeliners Podcast host Russel Treat welcomes the “Three-Phase Flow” trio of Dan Sensel, Jason Dalton, and Kyle Miller from Marathon Pipe Line to discuss the importance of planning and cooperation to maximize hydraulic design.
You will learn how changes to pipeline design plans can significantly impact the engineering work, why the product being moved is just as critical as knowing how much product will be moved in the pipe, and how to enhance collaboration upfront to maximize ROI over the long haul.
Hydraulic Design – Show Notes, Links, and Insider Terms
- Marathon Pipe Line (MPL) is a subsidiary of Marathon Petroleum Corporation that owns, operates, and develops midstream energy infrastructure assets. MPL operates pipelines, storage tanks, and barge dock facilities.
- Dan Sensel is the Leak Detection Project Lead at Marathon. Find and connect with Dan on LinkedIn.
- Jason Dalton is the leak detection and hydraulics supervisor at Marathon. Find and connect with Jason on LinkedIn.
- Kyle Miller is the pressure control process lead at Marathon. Find and connect with Kyle on LinkedIn.
- Listen to Episode 54 – Leak Detection Program Management
- Listen to Episode 57 – Managing Liquid Pipeline Slack Line
- Listen to Episode 61 – Relief Valves in Liquid Pipelining
- Listen to Episode 69 – Instrumentation Issues in Leak Detection Systems
- Hydraulic Engineers support the design, build, and operation of pipeline systems to get the most out of the system without exceeding MAOP.
- MAOP (maximum allowable operating pressure) is the maximum pressure allowed in a pipeline based on the calculation of wall thickness, pipe strength, diameter, and allowable stress. The Department of Transportation (DOT) sets the standard for the highest pressure at which a pipeline may be operated.
- MOP (Maximum Operating Pressure) is the maximum pressure that a pipeline can withstand based on its design, function, and strength.
- Greenfield pipe refers to new oil and gas development in a completely new area. This is in contrast to expansion on an existing development.
- ASME 600 class refers to the maximum allowable non-shock pressure and temperature rating in a pipeline.
- Drag reduction is the process of injecting polymer chains into a pipe to laminarize the flow and reduce the PSI drop per mile.
- Drag Reduction Agents (DRAs) are additives used in pipelines to reduce friction and increase the flow of the product.
- Friction Drop Equations (velocity x area = flow rate) are used to determine the linear velocity in a pipeline.
- Popular equations include the Darcy-Weisbach Formula, the Moody Chart, and the Hazen-Williams Formula (friction head loss).
- Capacity Expansion Analysis creates a framework for the life cycle of a pipeline from inception to ultimate capacity of the system that ties in with the business development team’s expansion plans.
- The Iterative Project Development Cycle is a phased approach to project development and completion that builds upon itself. One change — even slight — could affect many other aspects of the project.
Hydraulic Design – Full Episode Transcript
Russel Treat: Welcome to the Pipeliners Podcast episode 73, sponsored by EnerSys Corporation, providers of POEMS, the Pipeline Operations Excellent Management System, compliance, and operations software for the pipeline control center. Find out more about POEMS at enersyscorp.com.
Announcer: The Pipeliners Podcast, where professionals, Bubba geeks, and industry insiders share their knowledge and experience about technology, projects, and pipeline operations. Now your host, Russel Treat.
Russel: Thanks for listening. I appreciate you taking the time, and to show that appreciation, we are giving away a customized YETI tumbler to one listener each episode. This week, our winner is Bruce Fulin. Bruce, congratulations, your YETI is on its way. To learn how you can win this signature prize pack, stick around to the end of the episode.
This week, the Marathon trio returns, and we’re going to talk about hydraulic design and working with the business development group. I think you’ll find this to be an engaging episode.
Welcome back. We’ve come up with a new nickname for the trio from Marathon Pipe Line. They’ve named themselves Three-Phase Flow, and you missed it because you didn’t hear our banter about the miscalibrated confabulator before we got on the microphones here.
With that, welcome back Kyle, Dan, and Jason from Marathon Pipe Line to talk about hydraulic designs. Welcome back, guys.
Kyle Miller: We love it.
Dan Sensel: Thanks.
Jason Dalton: Thanks for having us, Russel.
Russel: We were talking about this before we got on the microphone, and having a little fun at other people’s expense because they weren’t around to know, about this idea of hydraulic engineers and the challenge sometimes we’re faced with when the business development professionals are bringing their requests.
We put this episode together. The title of it is “Hydraulic Design for Business Development Professionals.” I think the tagline is, “What every hydraulic engineer wishes that all business development professionals knew.”
Does that kind of sum it up, guys?
Kyle: I think that’s pretty good.
Russel: I guess a good place to start is, let’s just talk a little bit, for some people that might not understand what hydraulic engineering is, what is a hydraulic engineer? What are you guys doing? What’s your role? What is hydraulic design?
Jason: Hydraulic design, there’s a lot that goes into that. Mostly, it comes down to making sure that you get the capacity out of a pipeline system that you want to while staying below your maximum operating pressure.
That involves where are your pumps going to discharge? What kind of flow rate are you going to have? What’s your delivery pressure? How much pressure do you need to feed the system? How is the system going to operate for the operations center or control center?
Russel: Sounds easy, if you say it fast. What information do you need to do all that?
Jason: You need an elevation profile. You need to know what you’re carrying in the pipe, butane, propane, cold lake crude oil, West Texas. You know the strength of the pipe, so what your MOP is, and what your requirements for flow rate are on a daily or hourly basis.
Russel: How is that different when you’re doing something that’s greenfield pipe, versus something that is I’m adding to pipe that I already have?
Kyle: Another way of maybe rephrasing what Jason led with, we like to say that we are the physics police of the company. Everybody wants to get more for less, but in the world of PSI, barrels per hour, drag reduction, you’re going to get what you get, within the laws and the confines of the way nature works.
What we do is really try to understand all those relationships. When we’re starting from scratch, a pipeline that doesn’t exist, the sky is kind of the limit in terms of — we can tell you different pipe sizes, what max operating pressures you’re going to need, how many pump stations you might want, how those are spaced apart.
On an existing system, obviously, we’re a lot less limited. If it’s old pipe, if it’s been cycled a bunch, it’s low MOP, that’s really when we start off by looking at drag reduction, maybe right off the bat. We’re probably maxing it out mechanically if we have a certain number of stations.
Our average spacing is 40 miles apart. If they’re all hitting their maximum possible discharge, you’ve got to go drag reduction. If we’re building a new system from the start, we’re going to try to get as much mechanical capacity as we can.
Usually, our main lines, we’ll build them to ASME 600 class, and then we’ll go from there in terms of adding.
Russel: Let’s do a couple of definitions here. The first, you’re using the term drag reduction and certainly, guys that are working in liquids are going to know what that is. Can you give us just a quick explanation of what is drag reduction and how is it used?
Kyle: Right. Drag reduction agent is a magical unicorn snot that we inject into products. Oh, wait, are we still recording? Oh, yeah.
Russel: I’m sorry, the technical term is… [laughs]
Kyle: It’s really magical unicorn polymer chains that help to laminarize your flow and reduce your PSI drop per mile. Obviously, without getting into vendors, we have several different cocktails that we use, and every different blend has an effectiveness that you can calculate.
We figure out what is the parts per million that we need to inject to reduce down to a certain PSI drop per mile. Let’s start with that.
Russel: The way that I think about the DRA agents is that basically, they make the product slippery. They reduce the friction losses in the pipe.
Kyle: Yep, absolutely.
Russel: It’s interesting, too, because I’m sure we could do an episode just on that topic. It sounds like you guys are doing some things and it might be part of the secret sauce of how you operate in terms of exactly what the agents you’re using and how you’re using them.
Dan: Yeah. I think our business development people will get upset if we started talking about all the ways that we use DRA.
Russel: Yeah, probably so. I think it’s helpful to understand that that’s part of this. The other thing that I wanted to ask, too, is obviously there’s pressure, there’s flow, and there’s pipe size.
What you’re trying to do is get to your optimal commercial operating state, given the combination of those three things. What do you find is easiest to address when you’re doing one of these projects? Is it the pipe size? Is it the pumping? Is it the MAOP? How do those relate?
Dan: I’d say pumping is probably the easiest one to manipulate. We can add pump stations along a line, or we can increase or decrease the size of pumps at a station. Replacing mainline segments, or building new mainline segments can be rather expensive.
When you’re talking about a new pipeline, we want to try to keep that line, as far as the cost of the pipe, as low as we can.
We have to balance costs between additional pump stations with increased diameter, while at the same time looking at how fast the flow is going to be moving through the pipe to make sure it’s going to have enough velocity to scour water or anything else out of the pipe.
That puts a minimum on the velocity of a pipe, but then we also have to keep it under certain velocities, to reduce our risk for surge pressures.
Jason: One of the things that, on greenfield versus an upgrade of an existing system that’s different, is the station spacing. Once you get your stations, in our experience, at least, closer than about 35 or 40 miles from each other, you’re running into operability issues.
Where, if you’re trying to get the highest pressures you can, and the highest flow rates, if you lose a downstream station, it’ll send a transient back and knock off an upstream station.
You can look at it from a development perspective, and say, “Okay, let’s just put a pump station every 10 miles on this pipeline, and get as much out of it as we can.” Yes, you can probably do that, but it’s almost inoperable just because of the amount of transients and surges that are going to be bouncing from station to station.
We always start with what’s Dan’s saying — you look at the pipe diameter first. That’s always the most important thing, your pipe diameter, because that controls your friction drop per mile.
Kyle: Diameter has an extremely large effect, so Jason mentioned, brand new project, the first thing we’re looking to do is size the pipe. Maybe it’s a situation where a 10 inch, you’re going to be maybe 13 to 15 feet a second.
We’re under our standard speed limit, you feel okay about your pipe erosion, but your friction loss is going to be very high. You’re looking at more stations. Maybe a 16 or 18 inch pipe, it’s going to be drastically reduced, by a factor of two, three, or four, you’ve reduced your friction drop, but you’re paying a lot more for the steel.
We’re trying to target a linear velocity in the pipe that checks all the boxes. For anybody out there who’s a fluid student, you’re starting out, we’re talking about flow rate equals velocity times area. Then there’s a lot of different friction drop equations you can use from that, but there’s only so many ways you can go with it.
Jason: One area where business development can help us a lot in this area, is that we need to understand if there’s expected expansion of that system in the future. If this is the first line into a new field or something like that, it’s going to operate at maybe a much lower rate in the beginning.
You need to plan for that later expansion and to understand we want to make sure that we’re not limited by pipe size five years from now. We got to make sure we understand that potential.
Russel: When you’re looking at that, particularly if you’re on the gathering end of a system, where flows are more variable, at least in the short term, what kind of time frame are you looking at? You’re looking at 3 years, you’re looking at 5, you’re looking at 15 when you’re evaluating these projects? What kind of time frames do you try to look at?
Jason: Realistically, about five years. We won’t be doing ourselves justice if we ever design a system so that the minute it’s turned on there’s no further expansion opportunity on it.
The bigger deal, for me personally, is to fully understand exactly what our friends and business and all that want to transit through the pipeline. If the requirement is, “We want to move 200,000 barrels a day,” 200,000 barrels a day of gasoline is vastly different than 200,000 barrels a day of Canadian crude oil.
If we design for one thing and the fluid type is going to be switched, the pressure drop per mile changes and the effectiveness of the DRA goes down. On the outside of the project, to Dan’s point, you want to know is this an intermediate step, which bench is there, and what exactly are we going to be moving through this line during its lifetime?
Russel: Yeah. Knowing a little bit about the business development side and the realities that those guys are up against, they don’t always know. If you’re hooking up to a new field, you don’t necessarily know exactly what that crude’s going to look like.
Russel: Until you get some wells online. Then, as you get more wells online, that may change. Obviously, there’s a lot of potential unknowns here as you’re working through this. What’s your process to get some boundaries around a case?
Dan: To begin with, I think that we’ll focus a lot on the worst case properties. Jason mentioned gasoline versus Canadian crude. Obviously, if we know off the bat it’s going to be a product system, even hearing that it’s going to be all gasoline and then you add diesel later, that can be an issue.
Diesel is typically the heaviest product we move, so we’re looking at the highest specific gravity, highest viscosity. Then we’re looking at lowest gravity, lowest viscosity, and highest vapor pressure.
Those are the big five for us. Highest and lowest gravity, highest and lowest viscosity, highest vapor pressure. We’ll put together, even if we don’t know for sure, we’ll put together a slate of common products that we move.
We’ll see how a system can handle those things from a pressure drop perspective, then you’re getting into batch effects, and that’s usually what we do if we don’t know exactly what’s going to happen. Honestly, you never know exactly what’s going to happen.
Russel: Well, of course not.
Dan: To Kyle’s point, that’s where there could be some disagreements between hydraulics and business development. We’ll run through, and we’ll go and model the line, and let’s say we’re doing a product system.
We’ll lay the entire system down in gasoline, and it’s going to achieve one flow rate. We lay the entire system down in diesel fuel, and it’s going to achieve a different flow rate. We would publish two numbers, we’re going to have a max instantaneous flow rate.
Let’s say 2,000 barrels an hour, but you’re not always going to have gasoline in a line, you’re going to have diesel fuel sometimes, and when you’ve got diesel fuel in the line, it’ll probably be around 1,500. The capacity we’ll deliver back is a mix of those two numbers, somewhere in the middle.
That can be a sticking point, as were you said here you can go 2,000 an hour, why are you only rating my system to 1,800?
Dan: When we talk about the system capacity, we say, okay, what are ways you increase capacity? You probably don’t upsize the pipe, but you could upsize the pipe, you could add more pumps, you could add DRA. Well, changing the slate might increase capacity, if it’s possible.
Russel: Right, that’s interesting to me, because I would not have gotten there easily on my own. That’s not necessarily something you would think about. Obviously, as you kind of lay it out and explain it, that makes sense.
I guess the process is really to try and create some boundary conditions around the fluid and the delivery requirements.
Russel: Yeah, that makes certain sense. Once you’ve got those boundaries around, I’m a little hung up. I’m going to play the business development guy.
Russel: Why wouldn’t you tell me your capacity is 1,500 if it’s diesel, and 2,000 if it’s gasoline? Why would you give me a single number for capacity versus a product specific number for capacity?
Jason: Because they go out with an open season, the business development side will go to an open season to the marketplace and say “I’m building a new pipeline,” say you’re building a pipeline from Dallas to Houston, and this pipeline is going to do 80,000 a day. They need to know that number.
Russel: They need a basis for starting.
Russel: Okay, that makes sense. Then, as the business development starts to get commitments, that’s starting to change the capacity?
Russel: What are you doing? Again, I’m getting hung up, because it’s starting to get really complex in my head. I’ve said, okay, here is a system, and here’s your baseline, what I think the capacity is. Then the commitments start coming in. You’re going to re-work all of your analysis and calculations, based on those commitments, I would think. Is that right?
Dan: That’s one option. If you have enough time to get ahead, and what we like to do is put together what we call a capacity expansion analysis. We’ll start with your base case. Your base case is going to be one pipeline, one origination station.
Then step one is you’ve got a need for more capacity, you put a mid-point booster. Step two, you need a little bit more, you start adding DRA. Step three, you add more pump stations.
When the final deliverable goes to business development, you outline a complete expansion study for this pipeline from inception to ultimate capacity of the system. They can tie in what their nominations are matching up with on your expansion plan.
Russel: That makes sense.
Jason: It’s really a playbook so that they can make the decisions within the boundaries that we set.
Russel: That kind of tees up my next question. What do those boundaries look like? How do you communicate that to business development?
Jason: Good documentation. We’d write a lot of studies, like Word documents, between 3 to 20 pages, depending on how sensitive and how complicated it is. We do this for every control valve, relief valve, pump, on anything.
Or, if it’s pipe that we spec out, and typically a capacity expansion analysis is the most complex thing you do because there are so many options. We’ll come up with maybe a couple of different pipe sizes if we’re early enough for that, different pump spacings.
Then as the project process rolls along, as your front-end loading progresses through the project, that gives us opportunities to tighten our numbers. As the slate begins to take shape, as the project team says “Hey, now we’ve sized the pipe.”
Well, when they size the pipe — we’re coming out of the March Madness season right now — the bracket gets smaller and smaller; you’ve got fewer and fewer choices. Now, we’re talking about number of stations, spacing and things like that.
It all sort of follows the project process, and we hand them a documented study to put it in their hands.
Dan: As far as constraints that we place on the system, we will specify the max viscosity of what the slate can be. We’ll specify, in some cases, if it’s like a batched crude line, we’ll specify what percentage can be heavy, or we’ll lay out the capacities based on the percentage of heavy in the slate.
We do put some limitations in there to try to narrow the field as much as we can. We definitely want to leave it open as well, so that we can maximize the business opportunities for that pipe.
Russel: Right. As I’m listening to this conversation, I’m thinking about the process. Generally, the long pole of the tent — from a construction standpoint — is getting the pipe rolled.
It’s also the biggest check you’re going to write in the construction. The biggest line item in the construction project is going to be the pipe. I would think that that’s probably one of the first things you’ve got to try and nail down is, what’s my pipe size going to be?
Russel: Look at that, I’m making stuff up, and I’m right. Let’s stop there.
Dan: All right, it’s been a good one. See you next week, Russel.
Russel: [laughs] Exactly. I think, here’s kind of the $60,000 question, and that is, what is it that most hydraulic, in your experience, what is it that most business development people either don’t know, or don’t have the sensitivity for, that you would like for them to know and have the sensitivity for in this process? What’s the part that makes you crazy, I guess?
Kyle: For me, it’s the fact that this all builds on top of itself. We’re doing an iterative project development cycle. To go back to your point about the pipe diameter, once you pick a pipe diameter, everything is based on that pipe diameter.
If the nominations come in higher than expected, and they come back and, “Oh, well, I need to go from a 12 to a 16 inch.”
Now, all of your duty points on all of the pumps that you’ve started to specify needs to be changed. All of the control valves that you were going to order, all that needs changed, and you need different motor sizes. Things that to them seem inconsequential may be inconsequential, but the fact that everything builds off of each other means that you have to basically start from scratch when small changes are made.
Russel: Given the level of analysis and work you’re doing to build these operating envelopes out, that’s a lot of work.
Kyle: Yeah, it’s not modifying pumps, it’s throwing pumps out.
Russel: You’re starting over. You go from a 12 inch pipe to a 16 inch pipe, you’re starting over from scratch, from an engineering perspective.
Kyle: Right. The only thing about your hydraulic gradient that’s the same now is the elevation profile. Everything else is up for grabs. That goes even further upstream to the throughput number.
Say, yeah, we told you 200, but now it’s 280, that’s possibly going to change the pipe and change everything else that we just mentioned.
Russel: Right. I’m trying to put my hat on from the other perspective, from a business development perspective, hey, if I can get more commitments and justify a bigger pipe, then that’s a good thing.
Dan: Yeah, they’re doing a great job.
Russel: Is there anything else that you would want for the business development guys to understand about what it is you guys do and such?
Jason: I think slate sensitivity is a big deal. Understanding that not all crude is the same, not all products are the same and that it can have a huge impact on what the capacity of that system is going to be.
Even switching from gas to diesel, or from light crude to heavy crude, or even changing the percentage of those within a mixed slate, can have a big impact on the capacity.
If it moves it enough, it can even change. Just by changing the slate, you can end up with having to redesign your pumps because pumps have a minimum operating speed and a maximum operating flow, and we got to stay within those bounds, as well.
What seems like a small change on paper can be a big change to our analysis.
Russel: Yeah, the engineering work that’s behind making that small change is big.
Dan: I think the other thing I would throw out there is a good hydraulic analysis, business development project, it can change the CapEx [capital expenses] versus OpEx expenses [operating expenses].
You can do a real quick hydraulic analysis, use some rules of thumb, throw some equipment in the grounds, and build it really quick and probably fairly cheap, but your pumps are going to be operating in suboptimal conditions and you’re going to be tearing up pumps, tearing up motors.
You’re never going to realize the full capacity of the system. If you do a good, in-depth hydraulic study, you’re going to end up with all the right size equipment and the system is going to run much more steadier, and more rateably.
Russel: That’s another really important, very important thing, from how do hydraulic engineers help their company achieve profitability? There’s a big difference in the way that pipeliners look at CapEx vs. OpEx.
Once your CapEx dollars are spent, you’re kind of done and you get to operate the system you have within its constraints and limitations. To the extent you can get that right, CapEx you pay it once, OpEx you just keep on paying and paying and paying.
Kyle: What Jason said is very powerful, and everybody in this industry should sit down and think about it. Project teams have their motivations. They’re looking at their cost index, their schedule index.
They’re going to get, maybe, benchmarked against other comparable projects in the industry. They want to keep that cost down. If we took every single system we had in service right now and magically upsize them two inches, everything went up one nominal size, that would cut a lot of energy costs.
Everything is related and you need to think about how long you want an asset to be in service. If we want to run it for 50 or more years, like a lot of the stuff that we still have, let’s do a really good job on the front end and not just try to whip through it.
Russel: Yeah, boy, you’re saying a mouthful there. Absolutely saying a mouthful. I think, actually, I want to make a request of you guys.
I think this would actually be a topic that maybe we ought to do a series of episodes on hydraulic engineering or hydraulic design and walk through the things we’re talking about but in a bit more detail? That sound like something you guys would be up for?
Jason: Sure. Can we get our calculators out?
Russel: Only if it’s a confabulator, those are the only kind I use.
Jason: Yeah, it’s in the shop, but we’ll get it fixed.
Russel: You putting a V-8 in that baby?
Dan: All electric.
Russel: All electric. [laughs] That’s great.
Well, with that, I think we’ve come to the end of the episode. I think I want to do the three key takeaways, here, for this episode because I think there’s some value in that, for a guy who’s not a hydraulic engineer.
I think the first thing is that a little bit of change means a lot of engineering work.
Russel: Because changing something as simple as a pipe size or a product type, I’m basically going back to scratch and starting over with my engineering. I think that’s the first key takeaway.
I think the second key takeaway is that the product envelope, I guess what you called the slate, the products you’re going to move and how you’re going to move them, is as big an issue, if not bigger issue, than how much you’re actually going to move.
Russel: Then, lastly, if you can spend a little bit more money up front and have a little bit more time up front, then you can make more money in the long term. That’s my three takeaways, how did I do?
Jason: I think that’s pretty good, Russel.
Kyle: I think you took good notes.
Russel: Excellent. Well, gentlemen, this is a pleasure, as always, thank you very much. We’ll see you next time.
Kyle: Thanks, Russel.
Russel: I hope you enjoyed this week’s episode of the Pipeliners Podcast, and our conversation with Dan, Kyle, and Jason. Just a reminder before you go, you should register to win our customized Pipeliners Podcast YETI tumbler. Simply visit pipelinepodcastnetwork.com/win to enter yourself in the drawing.
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Russel: If you have ideas, questions or topics you’d be interested in, please let us know on the Contact Us page at pipelinepodcastnetwork.com or reach out to me directly on LinkedIn. Thanks for listening. I’ll talk to you next week.
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