One of the many examples of the benefits of HDPE piping solutions is the low-impact installation methods. Horizontal Directional Drilling -or- HDD allows you to install piping under obstacles like roads, railroads, rivers and lakes without disrupting the environment or pausing transit.

Join us as our experts provide a full breakdown of the ins and outs (literally) of this specific trenchless technology.

Key insights include:

• circumstances that are conducive to HDD
• evaluation and preparation of the drill site
• detailed rundown of the equipment
• the advantages and risks

Garry

My name is Garry Bouvet, and I am great and happy and excited to be here today. We’ve got a wonderful topic. We’ve got a couple of great experts joining me today to talk about all things directional drilling or HDD, as some people know in the industry. Before we get into that, I want to go through a few webinar instructions for anybody who may be new to the program, understanding what we’re doing, all of your video and audio is turned off to enhance our quality of the production. If you’ve got feedback or troubleshooting issues related to zoom, please try to put those questions into the chat box, and one of our experts, Barrett, in here, will try to help you and get you squared away. And we’re anticipating a lot of questions. We hope there are. If you’ve got those about the subject matter, the topic that we’re covering, please drop those into the Q and A tab. I’ve got my friend and teammate, Jeremy Becker, in studio with us. He’ll look answer those questions as he can. He’s also going to be sharing some of those questions that might be beneficial to the entire audience. So drop those in the Q and A tab, and we’ll get to as many as we can in the program. But we’ve got a lot of information to cover with two outstanding guests, and without further ado, I want to introduce them. First of all, joining me here in studio from Mears group. Mark Mitchell, Mark, welcome to Louisville and welcome to Isco.

Mark

Hey, thank you for having me. It’s an honor to be here on the show. Certainly wonderful to be here in studio too. So looking forward to it.

Garry

Well, great. Well, we know you’re going to have a lot of expertise to share and benefit the audience coming in. And we also want to introduce joining us remotely. Jim Williams, Senior Engineer at Brierly and Associates. Jim, welcome to the program at insights.

Jim

Thanks very much.

Garry

Yeah, tell us, Jim, tell us a little bit about your background, for the audience who may not know where your background is and your expertise with this subject matter.

Jim

Okay, yeah, I’m Senior Consultant with Briley associates. Have about 30 years in the civil trenchless HDD industry with construction and engineering.

Garry

Well, fantastic. Well, we We know you’ve got a lot to share. I already gained a lot just listening to you yesterday during our our practice session. And Mark, tell us a little bit about your background.

Mark

Yeah. So I’ve spent the last 20 years in the construction industry and different facets or forms, but my first exposure to HDPE pipe was I did a handful of years with Sunbelt Rentals doing sewer bypass, so out there fusing up pipe, you know, multiple pumps going into a common header system. And so that was my first exposure to it. And then obviously, coming over to the directional drill world, get to look at plans and profiles every day. And, you know, it’s, it’s an amazing product with a ton of capabilities. So this will be a fun conversation,

Garry

Absolutely. Well, I know we’re going to have a wide range of audience, engineers, municipal personnel, other contractors, maybe so, a wide range of people sitting in today. So with that, let’s go ahead and start diving in to the topic today. And when we talk, you know about piping systems, right? They’re on the headlines everywhere. We’re seeing failures all across the country, right? Of pipelines that are failing, needing repair, needing replacement. There’s a variety of installation methods with piping systems and everybody’s familiar traditional open cut, that is still a primary installation method that we see, but there’s also rehabilitation methods like slip lining and pipe bursting. But new installations are being more and more being done with technology, a process called horizontal directional drilling, or HDD. And when we get into we start talking about HDD, there’s really kind of boils down to two, I guess, size ranges. We call it Mini and Maxi HDD. You want to you or Jim, want to explain a little bit about what those two terms mean,

Mark

yeah, so on distribution side, and I’m going to use that word a little bit loosely, but a lot of your smaller rigs pulling in the two inch up to 12 inch, let’s use that just for general conversation. That’s going to be your mini rig work. So you know, Vermeer ditch, which have both done a phenomenal job of creating this industry and growing the number of contractors in it. So you know, those rigs are going to be self contained. They’re going to have 10 foot of drill stem in baskets, self loading, high production machines that you know, that you see on the curb or on the edge of the street every day, those rigs that many. Rigs that’s going to take you up to 100,000 pounds of pullback. And that 100,000 pounds seems to be the breakover point to where we talk about the separation between Mini and Maxi rig work. So the vast majority of our fleet, we start at 140,000 pounds, pull back, go up to 1.3 million pounds of pullback. And you know, we also have a mini rig, 100,000 pound rig as well, but that really is a separation and the definition of the two. But you know, when we talk about a cost per foot, and when we talk about, you know, crew costs and the breakup of it, you know, your mini rigs, that can be a that can be a three man operation, and then when we step into Maxi rigs, you know, we’re talking seven, eight or larger man crews. You know, your mobilization cost is triple, three, four times. Sure what the mini rig is.

Garry

I mean, it looks like a circus coming into town, right? And a carnival with all of the trucks and the trailers and the equipment that you’re bringing in, right?

Mark

Not uncommon to have 15 to 20 loads of equipment, drill stem being a large part of that, sure, absolutely.

Garry

So we’re going to focus a lot of our talk today is going to be on the maxi portion of the directional drilling, and that’s a process that in my years of being in here is continuing to grow on a on a daily basis, right? We’re seeing more and more projects going as the capabilities for HDD continue to improve. And there’s some major advantages to doing a directional drilling project, and here’s just a few of them, right? I mean, reducing environmental impact. That’s, that’s one of the big ones. Nobody wants to see the roads tore up. You know, time and cost in faster installations, less material requirements, less traffic disruption. We all know. We all deal with traffic everywhere we go, to allow these days. So with any other things that you see from both of your vantage points, Jim and and Mark,

Mark

Hey, Jim, I’ll let’s jump in first if you want to.

Jim

Okay, yeah, I would say, you know, cost can be an advantage for HCD when you can considering restoration costs, fittings, valves, air release valves and that kind of thing. I mean, HDD can be an advantageous installation method.

Garry

Um, let me, let me ask you this when we, you know, when we talk about, about this, could more projects, you know, benefit from from using this technology. I mean, your days out there, Jim, and in the design world, do you see things that you’re like, man, that that could should really be a directional drill, or could benefit from being a directional drill project,

Mark

absolutely. And I think a lot of that comes down to, you know, property owners, you know, municipality specs, soil conditions, you know, we’re going to talk about geotech today, and that’s going to be a big one that, you know, depending on geotech, you know, I mean, when we talk about jettable soils, that’s a very cost effective way to put in pipe, right? And then when we talk about going into rock, that price increases exponentially. So there’s a lot of variables, but we certainly look at a lot of projects. And I had one come across my desk two days ago, and the the owner of the project showed me his alternative and how many road boards it would take, and how many road closures, and just all the other obstacles that he had to go around. And he says, Hey, can we do this? And I said, Absolutely, get us there, and let’s go.

Garry

Yeah, that’s awesome. And Jim, from your your perspective, what? What do you think prevents people’s apprehension or reluctance to use directional drilling for their project?

Jim

Sometimes there’s a perception that the cost will be prohibitive, which often is not considering all the aspects like mentioned before, but I think also just the technical installation, maybe issues with IRS being a concern other environment, environmental impact Sometimes, but I think that’s just a lack of education.

Garry

Sure. Yeah, well, good. Well, that’s kind of what we’re here today. Maybe we break down some of that, that barrier, that wall that you referenced, you know, some of this, projects or situations that make directional drilling, an optimal choice for for installation, you know, crossing a roadway or having to go, you know, having to lay a pipe somewhere on or near a waterway. You know, trying to do float and sink. We’ve done some of those projects can be done. You know. That may be the most cost effective every time. And directional drilling may be a better, better option going under the water feature instead of going laying it in it. You know, crossing railroad tracks. You know, housing developments when we get into the urban settings, right? Environmentally sensitive areas, wetlands, marshes and so forth. Is there any other aspect that you guys think of that we may not be covering that would be good for directional drilling?

Mark

Well, you know, right now, with an aging infrastructure, there’s certainly all sorts of projects that are popping up, right? I mean, we’re, we’re seeing issues across the country, whether it be rupturing pipes, you know, water features, I mean, the dam that just blew out up in Minnesota, yeah, right. Scary. What we’re seeing right now. But no, I mean, you really hit it there. And wetlands is a couple, right? Because, you know, ultimately, it’s, they’re large bodies of water to us, even access from the HDD contractor, you know, when we’re trying to, you know, do our regular checks, make sure there’s no IRS. I mean, they’re, they’re tough areas, right?

Garry

But, well, one of the neat things with directional drilling, and we look at and underground construction, had a recent study on that, I found that over 50% of the directional drilling projects were being installed with HDPE pipe. Now you can directional drill with other materials, but polyethylene is, is the pipe of choice, and there are numerous reasons why, why that is the case. I’ve always said from my perspective, you know, polyethylene was built for trenchless applications like directional drilling, because of the unique characteristics of polyethylene, we start with the way that the pipe is joined, the fusion, where you’re melting and heating, putting the joints under pressure, creating a monolithic piece of pipe. So if you’ve got 1000 foot of pipe, it’s one continuous piece of pipe. Flexibility, another big one for polyethylene. Polyethylene has a tremendous bend radius compared to other materials. That probably makes your life as a contractor a lot easier, a lot less entry and exit pits that you’re working with.

Mark

Oh no, absolutely, I mean, and we’ll talk about this a little further in a little bit, you know, obviously phenomenal bend radius with HDPE and so much so that, you know, we often see projects that are designed that, due to our tooling, due to our drill pipe, the our your HDPE pipe, can exceed our limits of our radius. So, you know, something else we’ll touch on today. But, yeah, no. Phenomenal product, ease of putting in. Jim I when you guys are, when you’re selecting a product, pipe, what’s your what’s your input on HDPE, and where do you see a best fit in your projects?

Jim

Well, I think the flexibility is really a big thing, because the pipe layout really comes into play, and a lot of projects, and being able to bend around roads and right of ways and easements where you’re not constrained by a very stiff pipe can really solve problems. So it’s that’s definitely a big benefit.

Garry

Well, that’s good. Are there other other important features? I mean, we’ve got, you know, how big is social disruption from your design side? Jim, is it? I think of it as a big issue, right? Traffic tie ups, shutting down roads. If we were to do an open cut, how does that impact your decision making when you’re looking at a project.

Jim

Yeah, I think it’s a big factor. And the good thing is that when you decide where you’re going to work, you’ve got one work area that you can prepare stay out of sight. You can put up sound walls to keep it to keep the noise to a acceptable level, and kind of shield the public from seeing what’s going on, kind of a out of sight, out of mind type thing. So I think it simplifies those projects in that manner.

Garry

Yeah, well, you know, I’m, I’m obviously biased a little bit, but I think polyethylene does bring a lot of advantages to the table. Let me ask you this mark from your perspective, how many jobs, directional drill jobs do you see where HDPE is not a good option? Man, I’m sure there are some right that I find a very market specific.

Mark

So, you know when, when we look at HDDs, obviously, municipal market is a huge market for us, right, right? Water being that water, wastewater. On the other side of it, we look at a ton of pipeline jobs every day across the country. And you know, those are predominantly steel projects. So, you know, when we talk about the HDD market as a whole, pipeline being a large portion of it, then municipal, then really specialty projects after that. But when it comes into that municipal market, there’s no question HDPE and the electrical market, obviously, okay, yeah, and the conduit, outdoor wind, any electrical conduit, when we talk about the, you know, the fpls or the Dominion energies, when they’re doing hardening and they’re taking above ground, putting it below ground. All great, you know, great projects specifically designed with HDPE.

Garry

Okay, good.

Jeremy

All right, yeah, we have a couple live questions. Garry, go ahead. Jeremy Muhammad asks, are any are there any limitations for HDD, such as flexibility, wall thickness, pressure rating, etc. And to add to that, Santiago asks, what is the minimum bin radius that HDD can can achieve?

Garry

I’ll start with the bend radius so the bend radius on polyethylene most common because we’re typically, especially when we’re talking about directional drilling, we’re looking at Dr 11, or thicker pipe. So Dr Eleven’s been radius is about 25 times the outside diameter of the pipe. That’s safe. Been radius for HDPE pipe that far exceeds anything that they would be able to do with the steel drill rods that you would have, right? So we’re, we’re more than capable with the polyethylene to handle that.

Mark

Yeah, no, and we’ll see a slide a little bit later on that that’s going to show one of our projects where we actually looped our pullback pipe out into the water. And you’re going to see the bend on this, on this 24 inch pipe. And yeah, to your point, exactly it, you know, depending on the size drill rig, depending on the length drill. No, we’re either looking at running a three and a half or a five and a quarter inch drill rod and to your point, Garry, yeah, your bend radius is going to exceed ours by three, four times, right?

Garry

Yeah. So never, should never be an issue with the directional drilling. Now, getting back to Muhammad’s question, talking about the the limits of what was Jeremy with the with the pipe.

Jeremy

Yeah. Hey, Jim, do you want to touch in on that, just from the engineering side first? Yeah, could you repeat the question? I’m sorry, what are the limitations to the HDPE installation method, including flexibility? Wall thickness and pressure rating.

Jim

Okay, so flexibility, I think Mark hit it on the on the radius, the pipe can match the drilled radius and pretty much all cases. So that’s not too much of a concern, and the bending stress can be calculated. Other limitations might be depth, just looking at ovality, which are defined in the ASTM or PPI documents for design guidelines. But it’s, it’s, you know, you can talk, look at your tensile stress, but in most cases, it’s pretty capable of most of most projects.

Garry

Well, good. Well, that we can obviously keep sending those questions. We we want to handle those. We want to try to get to as many as we can, but we’re going to keep diving in. We’re now getting at the point where we’re actually planning, we’ve identified a project, and we have to do the planning and preparation for that. There’s a lot of things that go into. We can probably spend a whole couple hours, if we wanted to deep diving on this particular topic from both of your perspectives. But, you know, we’ve got several noted up here. I don’t need to read all of them, but this is a really key step in a successful project, right coordination between both engineering and contractor operator.

Mark

Well, absolutely. And this is where, you know, I mean the first thing when, when we get a profile, it’s, it’s looking at the profile, looking at geotech, right? And then once we look at those two, then we may go to the spec book and then see what parameters that we’re operating under, you know? But you know, soil conditions, border logs. Can’t stress enough the importance of border logs. Us, you know, especially when we get into rock, right? Because oftentimes we’ll see borlaugs, and we’ll see, okay, it’s limestone, but knowing those compressive strengths is imperative. And you know, we have a lot of history. I mean, we’ve drilled across the country, you know, our guys, we have a lot of tenure within the organization, and we remember where we drilled, and we remember where we’ve lost returns, and where there’s been fractures. And, you know, unfortunately, you remember the bad ones, you know, or so there’s that. And then, you know, when I when we talk to our tooling providers, right? I mean the guys that we’re buying our reamers from, they keep a ton of data right? Our our locators that are doing our steering, you know those guys? I mean, they’ve been all across the country, right? I mean, we’ve all drilled, we’ve all worked together all across country, and and we all have an idea of what’s there, but still, it does not stress enough how important that geotech is, and and given us, giving us the best chance for success to know what we’re drilling into. Okay?

Garry

Jim, from when you get the you’re responsible for the bore, you know the boring information, right? The drill, the bore logs and so forth. How? I’ve gotten this question before, and I’ve never really thought much about it. But you know, if we’re doing a waterway that’s, you know, going significantly deep, how are you getting the bore logs or a highway you can’t obviously bore through a bore through a road to to get the information. What? What do you do in that scenario?

Jim

Well, we would out in the water. If we can get a barge to that location, we put a truck mounted drill rig on the barge, and go out and do borings in the river, in the whatever we know, whatever water body it is on the side, you know, the on the land, both sides, we definitely drill a hole on both sides, at the entry and exit points, and then areas, you know, where you’re in wetlands or other areas where you can’t access, you get it, you get as close as you can, and make the best interpolation that you can based on information available.

Garry

Okay, yep, and I guess that history that you referenced mark of previous drillings in in similar areas, or whatever, probably really comes in handy, right?

Mark

You know, it comes in handy for, for the initial, you know, for the initial value evaluation, but, but after that, I mean, we are heavily relying on, on those war logs, you know, because ultimately it, it adds so many factors to it, right, right? Are we going to need conductor casing? You know, and obviously, overall length of project, diameter pipes and determine what size drill and take there. But, you know, it certainly adds a lot to the big picture.

Garry

Yeah, and something you mentioned earlier, you know, frack, you know, frack out. There’s a term that we hear a lot in the direction of drilling, right? Um, maybe you want to explain, either one of you explain, kind of what that is for the audience, and how this preparation helps eliminate or avoid that scenario.

Mark

No, absolutely. So you know, as we’re doing our pilot hole, as we’re drilling down, we’re pumping drill mud and and depending on the profile of the soil and length of the drill, and just how many GPM we have to pump down hole to get that material back up to our cleaning systems, depending on soil borings and what that, you know, what those soils look like, or if it’s rock and if it’s fractured rock, You know, unfortunately we, we don’t know where that drone can go. So, okay, you know, we’re always monitoring downhole pressure, because we don’t want an IR, yeah, right. We don’t want that on our resume. You don’t, you know, nobody wants it, yeah, doesn’t want it. The project owner doesn’t want it because it’s an expensive, it’s a, you know, an expensive proposition to go clean that up so, you know. And that’s when, you know, on longer drills, we talk about using intersects, you know, and that way to help lower that, that down, hold pressure, and then also conductor casing, right? We’re not seeing a project a little bit later where we drove 200 feet of conductor casing on entry and exit, just to help mitigate or mitigate that risk.

Garry

Yeah, Jim, anything you want to add on that.

Jim

Only thing I would say is, you know, just emphasizes how important the geotech exploration is. And we can, we can estimate the form, what we call formation, limit pressure, which is a estimate of the pressure that the soil can contain while you’re drilling. So we look at those and compare those to the drilling pressure to make sure that we’ve got a reasonable safety factor based on the profile and the depth selected for the design.

Garry

Okay, fantastic. Jeremy, you got. Another question that came in?

Jeremy

A couple that kind of tie into that. One from Fiona, how do you design the boring fluid, such as the thickness and pressure? And second from Angel, is going deeper under waterways and wetlands, enough to avoid fracking? What else is done?

Mark

So I’ll take the first one, and then I’ll let Jim chime in on second one. So on the first one, our drill mud. And we could go, you know, we can certainly talk for hours about drill mud, but ultimately, the drill mud and, and what we’re going to mix up is so much going to depend on the soil that we’re drilling in and and what’s coming back out of the hole. So, or in a case where, you know, we’ve looked at some drills where there’s been a huge, or not huge, but you know, 400 foot elevation difference, and or you’re in Appalachian area, right, right? And now, now there’s a heavy potential for groundwater, so that’s also going to dilute your drill mud. So you know, whether you’re in sand or clays or solid rock that’s all going to contribute. You know, that’s why we have mud engineers. You know, on staff. Those guys are as a drills happening. They are regularly checking that drill, mud, adding additives as needed. But ultimately, that’s a that’s its own science in itself. And I applaud those guys, because they have their work cut out for them.

Garry

Yeah, no two jobs are ever the same, right? And that scenario, yeah, absolutely.

Jim

Yeah, I can. I can touch on that other question, as far as Depth. Depth is the biggest factor to minimize IRS, but you need to be in a in a good soil layer. So that’s why that soil borings, and understanding that is really important. Other things that can be done, or like Mark said, with the intersect pilot hole, that should reduce depending on the specific project, the pressure can be reduced, the max pressure anywhere from 20 to 50 psi. So that that’s a big factor there, using conductor casings, where you’re isolating the pilot hole from the weaker soils near surface. And then one it’s more of an operational processes to use a down hole pressure monitor while you’re drilling the pilot hole and also using the biggest drill bit compared to the drill pipe diameter, so your hole for the fluid flow is as large as possible.

Garry

Yeah. Jeremy, another one came in.

Jeremy

It’s one question, what does IR stand for? And second, what are typical drill mud pressure ranges, and then the release?

Mark

Okay, yeah, pressure. I mean, it’s really the majority of the pressure component is from the hydrostatic pressure. So whatever the mud weight is, your your hydrostatic is going to be about 80 to 90% of the overall pressure. So, you know you could be anywhere from 50, 4050, psi, up to 150 or more, depending on how deep the pilot hole is relative to the entry point.

Garry

Now we know why I brought these two guys in for this presentation. There’s no way I would be handling these questions. Tell you that right now, both of you guys, we all use these resources, right? I utilize a lot of these in my daily work with the piping aspect. But you know, from your sources, you know, there’s a bore a calculator, for example, you probably live in you and your team probably live in that world mark every day. How often do you guys, you know, utilize this information, these resources that are out there?

Mark

This is, this is daily for my guys you know, for my engineers on staff, they’re in this daily, you know, and, and you talk about these and, and I think we should touch on no dig, I Jim, I believe you’re on the board directors for nasdt No dig, just what a phenomenal organization they are. You know, all literature, they’ve put out the opportunities that give all of us to, you know, to get together, and, you know, as far as an educational platform, yep,

Garry

All right, so we’ve, we’ve done the planning. Everything’s set to go right now. We’re actually, we’re at Go Time now for the for the project. It’s. Same time. You know, we’ve got these basic steps that’s got to be followed for now, I know this is kind of simplified, right? This, this is me putting this list together. Mark, not your team, but, you know, we start with the pipe fusion. Obviously, you know, that’s near and dear to my heart of joining that HDPE pipe, right? We one of the big things is your staging area. You’ve gone through that in your planning where you’re going to set this up, you got to have enough space to fuse that out. You mentioned coming up in one of our project overviews, you see a lot of pipe looped around, spun out in a in a bay or Harbor, a major water body, but we’re fusing the pipe. You know, we got to fuse those long sections, because once you start pulling you don’t want to stop.

Mark

We don’t want to stop. But let’s face it, due to the constraints and congested areas, you know, midwells are common, unfortunately, and that’s all you can say to it. So no, I mean, we expect midwells, mid welds. The beauty of HDPE is just how quick we can make those midwells, you know, in comparison to the oil and gas world, where we’re dealing with steel pipe, where, you know, it might take eight hours for a couple welders to weld up a steel pipe. And then, on top of that, they have to, you know, oh, shoot, you know, they come in, they have to check the welds, and then they have to coat the joint. So, you know, beauty of HDPE is fuse it, let it cool, and let’s keep pulling right?

Garry

Yeah, that’s a big, big advantage. And you can see here on that picture, I’ve got the actual pull head. So that’s the first weld of the of the drill stem right there, going in, all right? So now, once we’ve got that, we’ve got the pipe fused up while, probably, while we’re doing that fusion, you’re probably also doing the pilot drill, right? Your rig is probably already started. The pilot is, oh, a pilot shot,

Mark

yeah, no, I absolutely hopefully, actually, hopefully we’re piloting, and maybe even Reman depend on diameter before, yep, okay, or fusion so. And once again, it comes down to lay down area. Just how much real estate do we have to not only fit in the the drill rig, the mud mixing system. We have our semis bringing in trailer loads a drill pipe. You know, when we, when we look at one of the case studies here, I mean, you talk about it tight. We were inside wastewater treatment plant so, you know, logistically, getting stuff in and out. And we can talk about, you know, just how we mitigated some of that on our project, but no so hopefully we piloted, you know, and when we talk about a pilot hole, we’re talking about our drill bit up front, followed by our bottom hole assembly with our locating tool in it and going underneath, following a pre designed drill path, and fingers crossed so we’re not hitting large cobbles that’s deflecting our drill bit, right?

Garry

Yeah? And you don’t get to find that out until you get there, right until we get yeah, that’s, that’s always one of those moments. But, you know, we’re doing this pilot, a lot big. What’s the common size on a pilot hole? I mean, what’s the pilot head?

Mark

So when we’re when we’re dealing with Maxi rigs, oftentimes we’re talking 95 inch, pilot, okay, there’s times that we’ve piloted with 12 inch bits. Okay? So really, really depends on product pipe, and you know the formation, geological formation,

Garry

Okay, And you’re tracking this head right the through the whole process, knowing the orientation depth and knowing the where it’s at, and depths and

Mark

Yeah, so a couple different things. You know, when you talk about mini rigs, those guys are typically using what they call walk over technology. So I’ll use digit track for an example. It’s a little box labor. The operator is walking along. He’s walking with that box, and that box is telling him the depth and the orientation of that drill bit, right, right? Yep. That technology is starting to make it into the maxi rig world. That’s a very recent thing. You know, it used to be that the walkover was good for 30 some guys would say, Oh, we can get to 50 feet. You know, now they’re seeing 100 foot. No kidding, so. But then, when we, when we go to the maxi rigs, a wire line or a coil setup. That’s one tool we use. And then gyro is another. And really, you know when, when we’re talking about our gyros and and steering and locating, we’re bringing in a surveyor. We’re bringing in a brown line for an example, and in rock a share. Well. So we’re bringing in a locator to locate that drill head force.

Garry

Okay, so you know where it’s at at all, at all times, right? Yes, sir, yep. So once we’ve got the the pilot hole established, we’ve come through on the the other side. But we’re not, we’re not done yet right now. We have to actually start making room for the pipe, right? And we you call that reaming, right? So you’re opening up a larger hole to accommodate the pipe. This process, when we were talking yesterday, maybe 234, times, depending on the size of pipe, maybe in the soils, yep, yep.

Mark

So depending on soils, obviously, in a jettable soil, you can make a much larger jump, right? Okay, as long as you have the mud mixing system, as long as you have the pumps to move that material, you know, you can make a jump from a nine up to a 36 when we’re going into rock. Not to say we can’t make that big of a jump, but depending on product size of the pipe, with the length of the drill, we are going to make incremental increases to get to that final bore diameter,

Garry

All right, so we’ve got that, that reaming once we get the proper the whole size that you need. Now, when we do that reaming and maybe Jim, this is a question for you, how big do you want that hole large, how much more space do you need outside the pipe? Is there a percentage that you look at, or what is it?

Jim

Yeah, the rule of thumb is to use 50% larger than the pipe. OD, up to 24 inch, and then 24 inch and up 12 inches, sometimes 14 inches, larger than the pipe. OD, okay.

Garry

And while that reaming and everything is going on, you’re constantly injecting like a lubricant, like bentonite, into the borehole. Is that correct?

Mark

Yeah. So to that point, we’re still adding drill mud. So as that hole opens up, as that hole gets larger, we’re still pumping drill mud down hole. And ultimately, you know, not only is that, that drone mud, you know, serving as a lubricant for the pipe, but it adds also what’s holding our our borehole open, okay, yep.

Garry

What happens to the spoils, all of that that’s coming out of that borehole, for that large diameter pipe? What are you doing with the with all that?

Mark

So that, that’s where our mud cleaning system comes in, into effect. So that mud that’s coming back to our entry pit, or potentially exit pit, depending on the orientation of the drill and which way mud going, we will pump that into our mud cleaning system. That mud cleaning system if, if you’ve been to a rock quarry where you see they they crush stone, and then it goes through a series of screens, right? I’m going to use that as a, you know, kind of a similar reference, just much finer screen. So we’re screening out the heavier materials, and I call it quarter inch chips, okay, you know, if we’re in a rock scenario, next screen, a little bit finer than that, and that’s filtering out some muds, and then a final, third deck screen, or maybe a dis depending on how a drill contract reads their mud cleaning system set up so and those materials are coming off, being dumped into roll off bins that you know are parked underneath the mud mixing cleaning system And then typically using a hydro back truck to haul those materials off.

Garry

Okay, very good. So really concern keeping the environmental impact at a minimum, essentially, yep, well, good. All right, so we’ve done the the and we now we’ve done the pullback. We’ve pulled that pipe back. Now with, with all pipes, there’s always a limit of how much force that you can be using on that pipe, and it varies by the pipe material, right?

Mark

So no, we’re, you know, we’re going to take in pipe size, length, and we’re going to calculate what that pullback loads going to be and, and something that I would like to touch on today is buoyancy control, and just how important buoyancy control is when we talk about large diameter HDB. So, you know, at that, I’d like to lean on Jim a little bit and let him maybe give a brief explanation of buoyancy control. You know, I’d love to touch on just, you know how we actually perform it, but from a calculation standpoint, Jim, can you jump in?

Jim

Yeah, sure. So especially for HDPE, because it is so buoyant, ballasting the water with clean or balancing the pipe with clean water really helps on the pull load. And usually it’s a. Filled pipe cool load is less than half than it would be if it was empty. So it’s a significant improvement. Let’s tensile, tensile loads be lower, pipe stress be lower. And you know, it also helps with pipe ovality offsetting external pressures. So there’s, there’s a lot of advantages to ballasting with HDPE pipe.

Garry

Okay, So now we’ve got the pipe pulled through, and we now have these, you know, we have to put our connections typically, when what I’ve seen on a directional drill, we’re, we’re doing the hard part right, and then we’ve got to reconnect back to existing pipe. And that can be done in a variety of ways. Maybe it’s an all polyethylene pipe system, and we we do a fusion weld. Maybe have to do that in the trench, right? Especially if you’re, you know, your bore path was significantly deep, and your pipeline is there. We’re doing that fusion in the ditch. You can see equipment. We can break down fusion equipment to do in ditch welding. We can also do electrofusion couplings, another form of fusion, that can make those tie in welds, or maybe we have to make a fitting connection to transition to another material, or like you see on the left, we’ve that is essentially what we have. We have a flange connection coming off of the directionally board polyethylene going to a reducer and then flanging down to, I don’t know if that’s steel or ductile iron, or whatever that case may be, right, those tie ins, you guys, do you perform that, Jim and your operations?

Jim

Typically, that’s going to fall on the prime contractor. Now say, you know, depending on the contract and the scope of work, we’ve certainly done it in our scope of work as well, okay, but more often than not, that’s where we leave it off. Leave it on the prime contractor, because they’re the guys digging that ditch, laying trench boxes in, hooking up to the to their product pipe. Right, right.

Garry

Yeah. Jeremy, another questions coming in.

Jeremy

Got a couple questions, what are the shortest, longest distances possible for HDD applications in large diameter, 18 inch and larger, are complex curves possible with large pipe. HDPE, and can you fuse the pipe while you’re pulling it?

Garry

The first I’ll answer. The third one, easiest, the fusion during the pull can be done. Think we mentioned that earlier, sometimes just because of the reduced lay down area, they’re going to, you know, have to stop and do a fusion. You want to minimize that from a contractor’s perspective, so your pipe doesn’t get locked potentially.

Mark

But back to the midwell, we are going to stop the drill rig and let that weld happen. And, you know, oftentimes, you know, like I said, it’s, it happens more often than not that there’s a midweld and and it’s something that we we plan for and we account for, because ultimately, it’s, it’s our crew sitting for, whether it be a couple hours or a day in some cases, yep.

Garry

So another question was, the longest, or what’s the maximum that you can pull?

Mark

So maximum. Maximum is obviously going to depend on pipe, diameter, thickness of it. Jim can chime in here too. As far as you know that the or you guys can giant chime in speck of the pipe. You know, we’ve pulled 6700 feet of four inch when we cross the Rappahannock River. Granted, that was smaller diameter. We’ve certainly done a number of HDDs over 3000 feet at 30 inch. And, you know, bigger diameter than that. I know we’ve done 1200 feet of 48 so. But you guys just had a record.

Garry

We did a record, and we were involved in, actually, in Miami a couple years ago. We’ve got that on a project later on, 54 inch pipe. I believe the one pole was 4000 some feet in Miami. So, and that may have already been broken too. It seems like those records kind of kind of changed quite rapidly.

Mark

Hey, Jim, what’s your longest one that you’ve been involved in?

Jim

Well, for HDPE, we just a couple months ago, finished one in Virginia. It was 5700 feet of 42 inch. Dr, 11, yeah.

Garry

So really, being there was a lot of variables to that question. Jeremy, I think that is really hard to to give a definitive answer, because, you know, these guys have talked about, you know, soil conditions and, and all the different things that go into an HDD project that could put limitations on what you can and can’t do

Mark

Absolutely and, and when it comes to that, I you. Know, there’s, there’s so many great experts. You know, this HPD world is a very small industry. We all know each other at some point. We’ve all worked together at some at some point. And you know, the best thing I can tell anyone from a municipality or from another engineering firm is, you know, to reach out, to reach out to the contractors, to reach out to, you know, the the engineering firms like Brierly that specialize in the HDDs, you know, there’s a number of engineering firms that you know that is their specialty, and we talk to those guys on a daily basis. So, you know, it was, you know, yesterday morning I had a phone call, Hey, can you jump on a teams call for 15 minutes and and look at a look at a pro or look at a KMZ with me, you know, 10 minutes to be done and, and I would encourage anyone to just reach out and get our input and let us take 15 minutes to look at a project, right? Yep, right.

Garry

So you know tips for success, right? We’ve gone through all of the steps I can’t express, and I know both of these gentlemen, the engineer, contractor collaboration, right? If you guys are working together, the the opportunity for a great project is, is off the charts, right?

Mark

No, absolutely. And you know, the exciting thing to see, you know, I think we’re starting to see more sea Mart projects, you know, construction manager at risk. I think that puts the prime contractor in a little bit better spot to then find a subcontractor. You know, get us as a driller involved. EPC projects that are now becoming a little more prevalent. I think that’s another great thing for the industry, because, you know, here’s a here’s an engineering firm, and that’s getting just that, you know, that much closer to the project and collaboration is huge. It really is. You know, at the end of the day, whether you’re the pipe supplier, whether you’re, you know Jim and you know briarley And the engineer, whether you’re the HDD contractor, our goal should all be that we have a successful project, right? You know, none of us should want to cut corners. We all need to have the same goal, and that the pipe gets in without damage, and that we’re leaving the owner with with a successful project that turned over and it works absolutely.

Garry

We don’t want them to have to worry about this down the road, and we don’t want to come back. Exactly, yeah, none of us do Yeah.

Mark

It’s not a cheap, not a cheap, right? And so keep that in mind.

Garry

Obviously, deal with experienced operators, right? We, we talked about that the last couple of days. You know, there’s some people that can do that, do directional drilling in the what we call the mini HDD, doesn’t necessarily mean they’re experienced and prepared for what’s what they’re going to encounter on a maxi HDD, right? So, I think experience does play a big thing when, when choosing a contractor for something like that,

Mark

Absolutely, and that’s, you know, that’s where I can’t stress enough. I mean, for, you know, in the pipeline world, I see it often. Know most of these projects, they might be the initial design might be done by one engineer, but when it comes to the HDDs, they’re bringing in a specialty HDD engineer, and it makes our lives a lot easier, right? Because we know the geotech’s there. We know the design profiles Correct. I mean, it’s just we know what we’re getting into. And oftentimes, you know, we see projects come along and, and we look at the profile, and, you know, back to that design radius, right? Even though the HDPE can do it, my drill pipe, my tooling, it can’t and, and oftentimes, we have to, you know, we know, bid those projects Okay, not to say that, somebody not to say that it can’t be done, but, you know, back to that likelihood of success and ensuring that we’re leaving a good product, right? It’s key. It’s it’s imperative. So, you know, I love to see when, when project owners and and design engineers bring in the, you know, the HDD engineering teams. I think the overall end product is a lot better,

Garry

Absolutely, and that’s what we all all want at the end a successful project. Speaking of successful projects, we’ve, we’ve kind of touched on them throughout. We briefly with man. Time is flying by. I mean, it feels like we just started a couple of case studies, just so you can see what what’s kind of been done, and we’ve touched on some of these. So I won’t spend a lot of time, but this was a 54 inch directional drill job in Miami on a sanitary force main really, down a major thoroughfare in. Town in the city open cut would have been extremely expensive and supremely disruptive to the community. And at the time this project was done, I believe it was a world record 3000 foot long pull, and then we also had another 1200 foot of 54 inch diameter polyethylene. So really, really unique project. Here’s, you know, I’ve got some. This is a picture of the this was actually a video of the job. And there’s some different snapshots from the from the job site at different points. You can see the pull head on there. Really, really, just a unique project. Now this one’s near and dear to your heart. Mark, this is a Belgrave wastewater outfall project.

Mark

No, so this was project we did a few years back and and thank you for including it, and because I think it brings up so many great aspects of directional drilling and some of the challenges that we come across. So you know this, this was utilizing intersect method, 3400 feet of 30 inch. And as you can see in that bottom right hand picture, we fused, we fused up 300 foot sections of HDPE on shore, loaded it onto the barge, and then, and then from the barge, fuse together that big loop. So, as you can imagine, if you see how tight that loop is, and when we talk about design radius, there’s absolutely no way I could bend my drill pipe in that pattern. So, but yeah, obviously marine aspect to this, working from a barge, how to catch rig up on the barge. And then I if I think there’s one more picture on entry side and exit side, we drove 54 inch conductor, pacing approximately about 200 feet on either side and and when we talk about, you know, adverting at IR, that’s what this 54 inch casing it was that you see down in the bottom left. So 200 feet, I believe, on entry side, that got us somewhere between 30 and 40 feet below grade. Okay. You know, at this job at incredibly soft soils, you know, just another, you know, add complexity to the project. And then in the bottom right, obviously the crane and the barge, and that was during pullback, and, you know, supporting that pipe. And, yeah, just but on entry side, being in that wastewater treatment plant that top left picture, if you see the clarifier tanks, we are positioned just to the right of that so not a lot of work room whatsoever.

Garry

Yeah, yeah. Really unique project, but it just shows what can be done with the proper planning upfront and communication and coordination with everybody make this a successful project, and the last one, just to touch on briefly, King County Water out west in Washington, another I believe wastewater line, directional drilling was really the only, only path that they could do, saved a lot of time and money by being able to do, do this directional drill. Here you can see some of the projects kind of, again, another Marine. We got some stuff. We got tugs, pulling pipes, stringing it out on the water, prior to the pool. So just, you know, a lot of those things that go in go into successful project, but real briefly. Oh, Jeremy, we got another question.

Jeremy

We’ve got a handful of questions that we can address here. One that’s come up a couple times. Are we seeing HDPE being conducted in Canada?

Mark

Yeah, so for Jim and I’ll let you chime in on this too, because I think you were up there. But Mears, for a lot of years, we drilled a lot in Canada. You know, I would say at least from the pipeline side of the world. I mean, they are doing some, some large, some very large drills up there. So I have to applaud all the guys working up there, tough working conditions. You know, when I was talking to our superintendent about it, and he was telling me how far remote he was, I think he was two hours from camp. Camp was four hours from the closest stoplight, you know, and then plus being up there in the bitter cold, you know, trying to keep drill rig, trying to keep the mud from freezing up, just tough working conditions. But Jim, have you had any experience out there?

Jim

Oh, yeah, quite a quite a bit. Yeah, they there is a lot of oil and gas, HDD work done, especially in Alberta. But there’s, you know, municipal work done all over the place, up in Canada. So I. Don’t think it’s any different from the US, just proportional to, you know, the size of cities and whatever, but plenty of plenty going on up there for sure. Yep.

Jeremy

Okay, another one we have is for railroad crossings when they require a steel casing and you want to use HDPE. What do you recommend?

Mark

So oftentimes, in in shorter railroad crossings, you’re going to see an auger war application, put, push that casing in, and then, obviously, you know, pipe spacers can be used, and rare HDPE pipe can be, can be slid in that steel casing. You know, I think we’re, we’re typically on the HDD side, where, worse, where we see those railroad crossings, it’s in conjunction with another, whether it be a wetland or a river. But if, if you’re just, you know, if it’s just that section of railroad, especially in the municipal market, more often than not, that’s, you know, a shaft on either side, and somebody use an auger board to push that casing across.

Jeremy

Do we have time for more?

Garry

Yeah, we can do, do a couple more. Let me before we get into those. Jeremy, let me just quickly run through because I know there’s important for some of the audience on here. I just want to touch on, you know, ISCO, who we are. This is why we’re able to be here today. Have this studio and all this great help. You know, as we are an HDPE focused supplier, we’re the largest distributor in North America with, you know, equipment, pipe, custom fabrication, if you need structures, if you need engineering, estimating help, we’re not HDD experts in the engineering side. We’ve got resources like the two gentlemen with us today, but we know how to get in touch with them. We can help with with all your project designs. We also have a lot of resources available for you, from library, from videos to other podcasts, insights, anything related in the polyethylene world. Check us out on our website, a lot of different places to find us. Our CAD library is always available for fittings, and right here, this is an important one for the audience. If any of you are needing CEU credits, please take a moment. I’ll leave this screen up. You can scan that QR code and complete the information, and we’ll get those credits sent out to each of you so you could submit them for your requirements. So I’ll leave that screen here. So now, now, Jeremy, let’s go ahead and take a couple more questions. We’re coming up on that hour. Sure.

Jeremy

Mark, you mentioned cobbles earlier. Someone asked, How do you handle HDD drilling where there are sand and cobbles? So ultimately, that’s going to depend on the size of the cobble, you know, if it’s sand. I mean, we’re typically looking at a little bit heavier drill mud to help seal that off, to keep that hole open. Cobbles and also depend on size drill rig, some of them. We, we can work through big cobbles oftentimes during pilot, you know, you can, you can hit a cobble that deflects, and then at that point, you know, back to our steering engineers and trying to get us back on track of that profile. It can be a timely and expensive proposition and and ultimately, you know, those soil conditions, we work around them every day, you know, but that just adds to the complexity of it. So don’t think that it can’t be done because we work through it. But just understand that, you know, our price per foot, or Sandy, cobbly layer of soil, maybe a little bit higher than something that we know we can get absolutely so

Garry

Well we’re right on up on the hour, folks and lot of great questions. If we didn’t get to your your question, we will respond to it offline and send you all the necessary information. I want to thank my two guests today, Mark and Jim. Really appreciate you joining us, really adding a great level of expertise to this subject matter that’s continuing to grow in usage and acceptance across the country, and we want to continue that. So thank you very much, both of you for joining us, and for all of you who joined us, thanks again. We appreciate it. Hope it was beneficial to you. Keep checking our website out for additional information on upcoming insights on different topics that are hopefully. Beneficial to you as well. So in the meantime, thanks again. Have a great Fourth of July, upcoming next week, and until then, happy fusing you.