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Revolutionizing Geothermal Energy: New Patents and Technologies with Dr. Chris Liner | Ep 339
00:29:56
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Oil and gas production is the union of natural systems with advanced science and complex engineering. Smart people across the globe create this
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remarkable place we call Upstream. And each day brings a new challenge. This is the Oil and Gas Upstream
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podcast where we look at how these systems come together and learn from the people who make it happen.
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Welcome to Oil and Gas Upstream. I'm Elena Melkert, your host. Some of you know me as the former director for Oil and Gas Upstream research at the US Department of Energy. I retired from the doe, founded Energia Consulting and joined the Oil and Gas Global Network. As a podcast host, I want to shout out to my sponsor ifs. Through one competitive platform, IFS supports the unique needs of the oil and gas industry, resulting in streamlined workflows, automated business processes and lower operating expenses. Expenses through improved efficiency, all of which can help you maximize asset performance. Learn more@ifs.com and now I'd like to introduce today's guest, Dr. Christopher Leiner, professor at University of Arkansas and science advisor for RAM Geothermal. Welcome to the show, Chris.
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Thank you, Elena. I appreciate you putting me on. Thank you.
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Great, great. We met at Ciri Week. We tried to record there and we had some user error. So I'm grateful that you're re recording with me here today. I know a little bit more about what you want to talk about here today and about geothermal. I did go to the geothermal house there at Sarah Week in Agora, but tell us all about yourself and then tell us about RAM Geothermal.
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Well, it was quite a week we had at Cero Week. We had some excitement on our recording, but also I think they had 11,000 people there. You've probably seen some of the numbers and the geothermal house was awesome. It was like you were in a subterranean cave with lava flowing down all the walls and some great demonstrations in there, some great interviews. So it was lovely. So my background is I've got the checkered past. I have got an industry background. I've worked with Western Geophysical Research in London. I worked with Conoco as an exploration geophysicist. I worked for Saudi Aramco in Dharan in their Advanced Research Center. And academically I've had academic appointments. University of Tulsa, University of Houston and currently since 2012, University of Arkansas.
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Oh, that's great. That's great. And tell us about your organization. Maybe tell us about University of Arkansas or if you want to go right into RAM Geothermal.
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The University of Arkansas is. That's my institution. I'm in the college, Fulbright College of Arts and sciences, Department of Geosciences. I was the chair of the department for six years and then two years as an associate dean. And that's after being the president of the Society of Exploration Geophysicists. So it seemed like all I did was manage things for a very long time. But a couple of three years ago I was stepping out of that role. Felt like I wanted to get back in the classroom, get back in touch with students. And it gave me a chance to really think what I want to work on. And several pointers had lined up on geothermal that I thought geothermal power generation at utility scale was where I wanted to put my efforts. And that's been the case. And part of the consequence of that was some patents, patent applications through the University of Arkansas, which were filed last fall and licensed this January by RAM Geothermal. So RAM is a startup company in Tulsa, Oklahoma. The RAM Energy, the parent company, has been around since the 1980s in oil and gas. So they have deep oil and gas experience in conventional and unconventional drilling operations. All of the things that the new geothermal lines up with.
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Yeah, yeah, it's capital R, capital A, capital M. Does that stand for something?
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Not as far as I know.
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Oh, okay. All right. Very good, very good. Okay. Do you want to tell us about your patent and the work in geothermal and all of that?
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The patents are in two different fields. One is about characterizing the subsurface. What you really want to know in order to estimate the geothermal power potential is you need to know the temperature as a function of depth. The geothermal gradient. This is usually described as. But if you really look at it, the increase of temperature with depth, and by the way, it doesn't increase from the surface, it decreases into a low zone and then it increases. That's the cool that you feel in caves and when you go in places like that, and that's the basis of geothermal heat pumps is it's around 60 degrees, maybe a little bit more year round. And in the summer you can use that to help cool the house. In the winter, you can use it to help heat the house and district. Heating and cooling of that kind is a very big deal around the world. But what we're talking about is in the deep subsurface below, say 2 km there, the temperature increases, but it's not a straight line. It's actually more complicated function. But the linear geothermal gradient is a useful approximation. But our first ip, I'll just call it IP for patent pending technology. First IP is how do we make an estimate of the reservoir temperature down there at depth. The typical way people do it is they look at bottom hole temperatures from oil and gas wells. And if you know how that works, you've got your drilling, you're circulating, when you get to td, then you shut in for a while, then you take the reading and that's the mud temperature that you will use to correct the well logs for estimating things like oil and oil saturation, gas saturation, etc. And it's perfectly suited to that purpose. But as an indicator of the true temperature down there, it's really pretty poor. And because the circulation time is typically not recorded and neither is the shut in time and neither is a mud temperature at the end of circulation time and neither is the mud pit temperature at the surface or the ambient temperature at the surface. And you would need all of that in order to do a really physics based deterministic inversion and figure out what the real temperature is. So around 2020, some USGS people published a really nice study that showed if you just take your bottom hole temperatures, you can imagine a plot that is horizontal axis temperature, vertical axis is depth increasing down. You plot all of your bottom hole temperatures, each one is a point on your plot. And you think about putting an anchor at the surface at the average annual temperature of the location and you just swing down a geothermal gradient until you touch your deepest, hottest bottom hole temperatures. And the idea is because this is such an economic driver in oil and gas to get these temperatures right, you have to assume the sensors are accurate because they're recalibrated for every job. It's just part of the business. So what that really tells you is that some unknown combination of circulation and shut in time at this particular bottom hole temperature, it was left there longer for reasons we'll never know, and it actually got closer to the true temperature. And we call that the lower bound of the geothermal gradient. It could be better, but it can't be worse. And that's state of the art right now. Basically.
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Yeah. Could you take me through? I didn't realize about the bottom hole temperature. I guess in my mind I said oh, that's interesting, but not how accurate it was or how it was taken. It is a data point and we obsess about how, when, where you take data, the process has to be the same for every other measurement we take. But I didn't think about bottom hole temperature.
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The way to think about it is that it's not a bad measurement. It's just we're using it For a purpose. It was never intended.
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Okay, so for oil and gas it's good enough.
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It's perfect. Okay, that's what you want.
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That's a new feature moving into the whole data analytics of everything. Right. Whenever you penetrate the earth, you're going to be getting information. And now we're realizing that it's not universal.
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And I'll just say that's been known since 1946 at least. A very famous scientist, Bullard, published a paper, 46, 47, describing exactly this. And there's 50 years now of bottom hole temperature corrections, which people have attempted to get the true temperature from the bottom hole temperature through various means without knowing circulation or shut in times. And sometimes it's worked pretty well in certain basins. But then you go to a deeper horizon, a different area. It's. There's just no universal correction. So that's the status of bottom hole temperatures. And our IP takes a different look at this and says that based on the physics of poor heat loss and all that stuff, if you look at it, it's actually operating and you can make some measurements at the surface. You can talk to the operator who knows information about the well and the way it was drilled and cased and everything. You can basically non invasively, meaning you don't have to shut the well down, do surface measurements and calculations and get the true temperature and depth. And that means that the 900,000 operating oil and gas wells in the US are potentially good solid geothermal data points.
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Oh wow. That speaks so much for the potential for geothermal because that's a fundamental measurement. Right?
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Right. When you're thinking about moving geothermal east of the Rockies. Because right now the geothermal that's being stood up by Fervo and other great companies, Oromat Sage is headed that direction. It's in the west, it's in Utah, Nevada, places that have high geothermal gradients. But if you're going to move east of the Rockies, then you've got this enormous base of wells that could help us realize the potential.
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Okay, Chris, so that's the first patent. What's the other patent?
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The other patent is, involves the way people historically have drilled wells in both unconventional reservoirs and for oil and gas and for geothermal, which is the idea of a doublet. And if you look at the way things have gone, it's really amazing to me just how recent all of this is. If you look at a geothermal doublet drilled the way people are doing it right now, where we drill down and we go horizontal, we've Got an injector. We've got a producing. We do an oil and gas style frack between these wells in hard rock and granite. The first of those really in the world of that style was done three years ago. There was a paper, a famous paper by Joshi back in 1986 talking about horizontal drilling. And at the time he wrote that paper, there were 20 horizontal wells in the world in various places around the world. And that's where we are in geothermal right now. There are about 20 geothermal wells like I just described. We are in the industry like the oil and gas industry was 50 years ago. It's really an amazing, exciting time.
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Yeah, let's back up a little bit because you threw in the word doublet and some people may not understand, not appreciate the whole like geothermal approach. So there are different styles depending on the options with the heat and how you want to pursue it. Right. I guess it's a risk and a reward kind of assessment. What is the best strategy for this particular spot of heat? Could you just do a few fundamentals about geothermal?
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The idea is that in these places, like out west where you've got granite, it could be naturally fractured, could be a fault here and there, but it's basically as far as poroperm goes, porostein permeability, it's impermeable, near zero porosity rock. And you go in with two wells a certain distance apart and you do a frac in one or both wells to introduce fracture porosity between the wells. And then you inject water at maybe typically 75C in one of the wells and it percolates through. You set up a pressure differential between these two horizontals and it percolates the water through the reservoir, picking up the heat and it's produced out of the producing well. And then it goes into a surface plant called a binary cycle power plant that can convert part of that heat energy you've harvested into electricity. And that's the way things are done right now, today. And what our patent is about is a bit of reimagining of how we could do this a little bit better. One of the big things that's been pushing for the last two or three years has been to reduce drilling costs because that's such a huge part of a geothermal project like this. And the DOE has had a project they call the moonshot. By 2030, they wanted to have the drilling cost on a sort of per foot basis in these situations come down 90%. There's been tremendous progress on that. Just in the last two or three years, several papers published on this. You have to develop new drill bits. You have to develop things that work in high temperatures. You have to work with different environments. You're cutting through very hard rock, it's granite, there's that progress. But what our design aspects of this are is that we can also think about through design changes, lower the cost of the drilling cost per megawatt. For example, let's say that you're going to drill a 100 megawatt plant and every one of your doublets can make 10 megawatts. So you're going to drill 20 doublets, that's 40 wells. As you move them across the desert or wherever you are, you lay them down like a zipper, if you will. And every four or five wells you've got to move and establish a new drill pad because it's marching out across the desert. What our technology does, it says instead you could wrap that around on itself while honoring the stress field, which we'll talk about here in a minute. And by wrapping it around on itself, you could drill those same number of wells from a single pad. In the Permian Basin they're routinely drilling 30 wells from a single pad offshore up to 90. This is mature technology. And by doing that you not only save on establishing drill pads, but the surface footprint is small enough. You can think about doing this in an urban landscape. You don't need 50 square miles of nothing in order to lay one of these things out. And that's where the second patent comes in.
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Excellent. So just to contrast the original geothermal, I guess we have heat pumps at the surface that's very shallow. We're not talking about that, we're using the. I'm going to stop right there because I don't know that much about a heat pump. But in terms of geothermal, the Department of Energy invested the earliest dollars in programs like the hot dry rock and also tapping into geothermal water laden deposits. I guess I want to say if we think about at the surface we talk about hot springs, but if you go down deeper and then harvest the water and use the heat from it to create steam for a turbine to generate electricity. And that's just one. But those are unique locations around the world and it won't last forever because eventually you use up the water. So then the next is to go to a place where you can put, inject water and then produce it back out of a single well, or as you said, two wells, doubles, double it, inject in one and then harvest the water from the other. And by hydraulically fracturing between the wells, I guess is a way to put it, you would create more surface area for that heat against the water to touch the rock, to gather the heat. Am I on the right track there with.
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You're right on, Elena. That's it.
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Okay.
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The way we would say that is traditional. The first kind of geothermal from 1906 and somewhere in Italy is one of these, is when you're in these amazing hot places like Iceland, Italy, parts of Turkey, Indonesia, northern California, the Geysers, the largest geothermal field in the world. And those are magic places that are exploited and will continue to be exploited. Then came the hot dry rock phase, which is where you do an engineered and by the way, EGS engineered geothermal system, sometimes called advanced geothermal systems. That's what we're talking about. But the earliest version of this, that was done in the U.S. also in France and in Germany, was called HDR Hot Dry Rock, where you've got hot dry rock and you are going to frack the rock and then you inject water down there and it will flash to steam because the rock is very hot, very hot rock and it flashes to steam and then it goes through a steam plant. Just the same way the steam from a coal fired power plant turns a turbine, which turns a generator, which makes electricity. So that was the way that worked. But the problem was around 2009. It was in all three of the locations I named. They had serious induced seismicity because when you introduce water into hot dry rock and it flashes to steam, you get a pressure pulse. That ensemble is enough to frack the rock and induce earthquakes. And they had to shut down the world's biggest hot rock projects around 2009, just about the same time. I will mention that the shale revolution hit the US 2006. 7, 8, 9. So there's a real convergence there. But the new version of this, one of the new aspects is that the water we put through never flashes steam in the subsurface. It goes through, it goes in at 75, it comes out around 180, 185, maybe 200. People are interested in taking this up toward 300C. But if you get above 300, you start flashing. And now you do get more efficiency on the top equipment with a flash plant. But if you put it through a binary cycle power plant at say 185, and the way these binary cycle power plants work is they've got a second fluid in the plant which is in a closed loop that flashes to steam at say 75 degrees centigrade. So you put your hot brine through a heat exchanger with that secondary fluid, it flashes to steam. And equipment up on the surface, no earthquakes. And then it flashes to vapor, turns the turbine, makes power. So that is the way the modern incarnation of this works. But they do still have a system for microseismic monitoring. They both typically, you'll have geophones at the surface. You could also have down the wells, you could have what they call DAS digital or distributed Acoustic sensing, where you a fiber optic cable to measure all this. But by whatever process you're monitoring as you do operations, you've got a traffic light system. Green means all the seismicity is so low, no difference, no everything. There's a yellow band where if you start getting events up in the yellow band, you have a protocol. Maybe we slow down pumping something like this. If you get into the red band, there's a protocol that you have to stop operations. And this right now, Fervo is standing up to 500 megawatt plant in Utah. And they have a traffic light system just like that's monitored continuously as they're building the plant. And it will continue when they operate the plant. We've learned lessons from the hot dry rock, but we're not flashing to steam in the subsurface.
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When you develop geothermal resources, I guess a way to put it, you're matching the amount of power you need to generate or want to generate, that is consistent with the geologic system that you have in place, which you can't affect the geology except to engineer it, but you can't create new geology. So it's a match between those two things, nature and engineering. And you put those together. And that's how. Because you talked about moving projects, I guess across the desert to get more and more power, basically is what you were talking about. And then you talked about the circle. So is that the power disk that we were talking about earlier?
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Yeah, the power disk is our IP that talks about how we could do this in a optimum compactness in terms of surface expression and in the subsurface. And you can do it just like in oil and gas, where you might have a shallow oil reservoir and a deeper. This thing can be stacked up so that you could in principle, in one location, what we were presenting at the CERA week, say zero weeks big, you want to make big ideas out there. So we had a thing we called the giga disk, which is a. From a single location, in principle, you could make a gigawatt of sustainable power in an area that has a geothermal gradient. Like out west? Yeah, and those kinds of places.
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Okay, so are we talking about drilling doublets to different depths?
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You'd have three different depths in that case. Yes.
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Okay. Okay. It sounds complicated. It sounds like, I want to say risky, but that's probably what your IP is all about.
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And we don't know that. In fact, we know that the first test of this needs to be a test of a very primitive version of this. Not an entire disk, but just a sort of a pie shot, pie sliced thing. And really the fundamental thing is that if you look at parallel laterals, okay, in a stress field, basically anywhere you look in the subsurface, there is a, it's all about what's called the sh, the, the shear horizontal stress. There's a minimum and a maximum. They may not be much different, but very few places are they exactly equal. And as soon as you have an sh min and an shmax, then what happens is when you start to frack the rock in a frac job kind of thing, those fracs are going to run along the direction of SH Max because they are going to open against SH Min. They're going to develop along SHMax and open along SH Min. So you'll take your doublet and you will turn it in the subsurface so that it lines up that way. But if you do that, if you've got a parallel doublet, you've also got the issue that at the heel of the, when you come drill down and turn, you have higher pressure. At the toe you have lower pressure. And as we, as you think about pushing water through the reservoir, you've got the same distance of rock between the heels of the wells and the toes. And so you're definitely naturally going to have more pressure across the heel of the well and you're going to sweep that area of more heat and you're not going to harvest the heat so well from the toe. So one way to handle that is that you don't make them parallel that you make toe in, heel out. It's a form of flow control. But where you don't need any equipment in the, you don't need slotted sleeves. Now, all of that may help as well, but it is a kind of a geometric flow control that can help you harvest the heat from this reservoir between the wells in a more uniform fashion.
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So I'm going to make a cartoon about what you just said because we have people who may not understand, have exposure or experience with horizontal wells and hydraulic fracturing. And how we do it, and the reason we use words like heel and toe is because we are simulating the angle of a leg and a foot and the vertical section of a well of what intends to be horizontal. It has to start out vertical until you come to a point where you turn from the vertical to the horizontal. And at that turn, it's like the heel of your foot, your leg, heel, foot. And then where you end, the lateral section is called the toe. And the toe is the farthest away, if you will, linearly from the surface. That is what we're talking about is at different sections, you have different exposure to the rock, different forces that are available to help bring the fluids from the subsurface to the surface and the like. And so now you're saying that if my two legs and feet were doublets, then the toes would turn in. Like when you're skiing and you're trying to stop.
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It helps. It helps. Yeah, yeah, that's right. And also, you got to remember that in oil and gas operations, in unconventionals, you're drilling one, you drill it down, you drill it out and you're producing along that well. You do frack to get the rock open and then you let the oil and gas flow back in. But geothermal is fundamentally different. It's between two wells. You're this kind of geothermal in that sense. It's much closer to the oil and gas case of a water flood or a steam flood, which is pretty mature technology in oil and gas.
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Yes, yeah, yeah, oh, yeah, absolutely, absolutely. Especially in conventional. Okay, Chris, we're almost out of time. Was there anything you wanted to share, Share or maybe highlight for the. This has been fascinating because we are definitely moving into a new world. We need all the energy that we can get. And so geothermal is definitely a way to increase energy security.
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You're right. We need everything we've got. If you look at wind, you look at solar, they're on about 20, 25% of the time. So if you need 100 megawatts of solar, you build 500 because you have that intermittency. Or you build 100 megawatts with battery. Okay, you've got it. So really you got to compare solar and wind with a battery. That's what you compare to a baseload power like geothermal, which, which really has the same. It's on 95% of the time or better every year. Just like nuclear is even a coal fired power plant or gas, they start life at somewhere around 70% of the time operating. But as they age, they have less and less time they operate. So the capacity factor, they call that drops as they get older. And with geothermal you have less of that effect, I would say. And as, as we think about trying to power the world, we all think is coming with AI, with more computing, with data centers, with all of that, we need more and more electricity. That's without talking about electric vehicle fleets eventually, but we need so much more power than we have now. And the geothermal power supply, if you will, from the Earth is basically limitless. And not. It's just that a thousand years from now, if you think what's the energy situation going to look like? It would have to involve a serious slice of geothermal and solar and wind and tide and nuclear, everything we could possibly throw at it. And what Grand Geothermal is trying to do is to accelerate this so that we can think about moving out of the Rockies, move east of the Rockies into the said basins. Because the things of course part of our technology applies out west too. We're working with people on that. But if you can move, if you can broaden the application of geothermal away from just areas that have exceptionally high geothermal gradients to more standard areas that's going to help the world, not just
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the U.S. yeah, oh absolutely. And we want everyone to have abundant power so they can be all that they can be using their AI.
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Well there's such a correlation between if you look at GDP as a versus per capita energy use, it's a very strong linear trend. What we call the lifestyle that we enjoy and know about and think about and we'd like to have more people enjoy around the the world is a high energy life.
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Yeah, yeah, absolutely. Very good. Oh Chris, thank you so much. This is so interesting and I so appreciate you. The learnings related to comparing oil and gas to geothermal and then your new ideas, big ideas, bold ideas presented at. Sarah, that's very exciting. Thank you so much.
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Thank you for having me on and thank you for all you do to keep people up to speed with technology at It's a very important function in the world. I really appreciate it. It's nice to meet you.
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Nice to meet you. Also I really enjoy talking with people. So. Dr. Christopher Leiner, professor at University of Arkansas and science advisor for RAM Geothermal. Thank you so much for joining us and thank you everyone for listening. This is Elena Melkert, your host for Oil and Gas Upstream. More next time.
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Thanks for listening to oggn, the world's largest and most listened to podcast network for the oil and energy industry. If you like this show, leave us a review and then go to oggn.com to learn about all our other shows. Don't forget to sign up for our weekly newsletter. This show has been a production of the Oil and Gas Global Network.