Interview with George King, Principal at GEK Engineering
Interviewed by Buddy Woodroof – May 2022
Buddy Woodroof, ProTechnics
Well, today we are pleased to have George King with us. And our introductory experts corner interview. What better person to kick off a new initiative than George King, I’ve said that about you in a number of different arenas. I remember introducing you as the first speaker in a session in Amsterdam and I remember saying, what better person to lead off this session than George King. So I keep saying that every time I introduce you, it seems like you’re always the innovator or the initiator. But George we’re extremely pleased to have you with us. For those of you who miraculously don’t know George in our industry, and I’m doing this remember George, so correct me if I get a few of these details incorrect. But George has a chemistry degree from Oklahoma State, start with BS, right?
And a master’s degree in petroleum engineering from Oklahoma State.
George King
I’ve got a chemistry degree from Oklahoma State, a chemical engineering degree BS from University of Tulsa and a master’s degree in petroleum engineering from the University of Tulsa. The last two I got while working for Amoco and going to school at night.
And then I wound up teaching at the University of Tulsa for 11 years. After Kermit Brown retired, I took over his completions course but all this was at night.
BW
Yeah, I still have one of your books from your completion course, fabulous compilation of information there. Well, let’s jump into some topics here that I think will be of interest to those of our group that will have an opportunity to witness or to view this recording. Let’s start off with FDIs… fracture driven interactions. How should we be applying what the industry has learned from FDI is going forward? We know a lot about it, we’ve garnered a lot of information, how should we be applying this?
GK
Well, a number of specialists are examining data from this right now and what we’re looking for, is to try to find the main causes or the trigger events which create a rogue length fracture. And I use the terminology from Neil Nagel, and I’ll explain that in just a moment, but there’s a number of specialists that are looking at and examining data from FDIs. Including people like Ali Daneshy, Mike Rainbolt, who has an SPE distinguished lecture on this topic, and Neil Nagel of course, from OilField Geomechanics, who explains the reasons or observed causes being rogue link fractures in some of these incidences where one perforation or cluster is taking the major part and driving a long fracture out now has to overcome some of the stresses in the rock, it will go towards the depleted sections very often.
But there are a lot of folks that are presenting on this and the best thing I can tell you is if you’re looking for the observed causes, and some of the evaluations of prevention methods, that you stay up with the information that’s coming up right now. Because as with fracture driven casing deformation, for example, we don’t know exactly what information we need to be looking at and what we need to record. So we need a lot of help in doing this. We need people talking to each other.
BW
Very interesting, very interesting. Well, that segues into our next topic. What have you learned from your leadership role in casing deformation during fracturing that the industry should be taking seriously at this point?
GK
Well, again, there are many engineering and geoscience specialists working the issue of casing deformation and let’s separate casing deformation from casing failure. Casing deformation a lot of times means I can’t get my frac plug pumped down to the location I want. I may lose some access, or try to find a better way to get there, but it’s a deformation issue. And basically, after reviewing a lot of publications, and there’s over 100 papers and articles presented on this, so far, many of them finding their causes, but different causes depending on the basin that you happen to be in. So it’s a basin specific thing and it has multiple causes. Now, we often look at all these papers that are coming out, but we don’t always read into them. There are over a dozen events or conditions that really increase the risk of casing deformation. And hard conclusions are hard to find opinions, well, then we’ve got a lot of those. But you can’t really drill a well, complete a well and then protect that well, on just opinions, you need to get the science nailed down.
So, a larger picture reveals that geomechanics, faults, bedding planes, drilled holes, smoothness now, I’ll talk about that in just a second or two, but good casing design, and better cementing are your major factors. But there are also trigger mechanisms such as shock loading, temperature flux, when you’re pumping a really cold fluid down your work string or your casing and hitting that hot formation, you cool that whole system off and you’re putting different stresses in your pipe, which can add to or really trigger a problem. There’s also the pore pressure driven stress changes in the formation, that and all of these things together can drive a border line issue across the failure plane and into a deformation problem. One of the big problems here is we need to know what data to collect. And now on this particular topic there’s a new SPE work group that has formed and been working about a year now. And first, we’re reviewing the information that’s out there and then trying to figure out basin by basin, what are the major influences? And within those basins what are the trigger mechanisms that actually kick this over the edge and create a deformation that loses access, or in some cases, you would collapse a point maybe you won’t have a release of any hydrocarbons and rarely do, but you’re losing the access to that well. So you’re losing a lot of this but we have a workgroup on that now and we are making some pretty good progress. I think that as we learned why it’s caused, we’re going to learn how to minimize it. I’m not sure we can ever completely prevent it from happening.
BW
What about offshore? Is this group looking at offshore casing deformation? I know in Green Canyon, among other areas, they’ve had a lot of casing collapse issues through the years because of the plasticity of the reservoir. It’s the kind of rock obviously.
GK
And this is one of those basin issues, is that geomechanics is probably the single largest unknown… and the thing most variable. It’s going to change over the life of the well.. As you produce fluid, you are changing the stresses by simply removing the load supporting elements out of the formation and causing some of those soft sands to really absorb more of that overburden and confining stress. That’s where you get into problems with the pipe. And as Neil Nagel is very fond of saying, “When the Earth moves, the pipe loses”. So that is a starting place. And it’s a starting place that we as engineers haven’t really looked at enough. We need to get in and look at the geomechanics section and see, what are the issues? Are they something similar, or something simple, like bedding planes, which are a big factor in Canada and in Argentina. Are they faults like the Sichuan basin in China? Are they rare occurrences like West Texas? We don’t see a lot for the number of wells that we have out there but we do see several that have lost access. We have to figure out what questions to ask and what data to actually record and that’s why this little SPE workgroup is so important.
BW
Is anyone doing any studying of geomechanical effects over time? Obviously, we can do some mechanical measurements, and we do that at core lab, but somebody simulating those changes over time?
GK
Over short periods of time, yes. Over longer periods of time, I think people are starting to look at that and we’ve looked at it in the Val Hall field where we first started seeing casing deformation in the mid to late 1980s. In that particular area, you would see a lot of stress movements, and they actually put in the equipment to do 4D seismic in there in the early 1990s and have got some real good information from that. But that’s the only case that I know of, that I can bring the memory right this second. There probably are others, I know there are more 4D experiments, but I don’t know of that many in detail.
BW
Right. Well, before we started recording, you and I were talking a little bit about the geothermal space. So my question to you is, how does one go about completing geothermal wells drilled in granite or metamorphic rock at 500 to 600 degrees anyway?
GK
Okay, and a lot of the design factors are already there, and some of the materials are there, not everything. Now, really, the drilling geothermal wells took a great leap forward recently with Fred Dupriest of Exxon and now with Texas A&M. He has got busy and helped the Forge project out in the University of Utah out in Utah itself. And the Forge project is an enhanced energy recovery project where they are circulating water between two wells through fractures that connect those wells and the idea is to harvest heat. Well, what Fred did is he looked at the… and the paper is SPE IADC 208798… and it’s on drilling workflows and really organizing and putting equipment and processes together to really make a good advance on this. This is something that oil and gas people can add to the geothermal area. When I first looked at geothermal about three years ago, and started reading papers on this bringing myself up to speed, it seemed to me like the geothermal space was operating in a knowledge area that we were in the early 1970s. There’s been a lot of push to go forward on this, the DOE has gotten effectively behind it and it’s funding, and we’re encouraging people to actually look at this. Particularly from oil and gas, there’s a number of us that are involved in this now.
BW
Speaking of, I can remember back about the 80s maybe, back in my pumping service days, we actually frac’d a geothermal well in New Mexico that had a bottom of temperature of 540 with conventional cross-linked gels. We since found out afterwards that we really didn’t frac at the 540 degree depth, it was more is more like the 385-degree depth, but it was just amazing that we could even do that back in that day.
GK
Well, these were just in the area there, they’re looking at about 230 degrees C, and just that’s over 400 degrees Fahrenheit, and they are establishing fractures. I got to watch via remote the last three fractures that they’ve done. And they were pumped… Liberty oilfield pumping did the pump jobs for us and it went off extremely well. This is just an example of getting really good oil and gas people into that space because if anybody can make it work, I think we can.
BW
I agree. Well, another big topic these days is the CCUS space. I understand you’ve been getting your feet wet in that area as well. So, what are your preliminary thoughts about that undertaking?
GK
I got my toes kind of damp, not my feet wet. But injection of any fluid into an underground storage zone, and I’ll just put storage in parentheses there, is going to need to overcome the pore pressure driven issue of seismic activity, which has become very, very big news anywhere where you are putting a lot of water on the ground, no matter if you’re disposing of the water from an oil and gas job or you’re pumping in water or pulling out water from a geothermal area. A lot of these geothermal areas are in areas where there is a lot of faulting and a lot of energy tied up in the rocks. So potential carbon capture, usage, and storage needs to be carried out very, very carefully here to minimize the seismic potential that it could be. And I know that DOE is working on getting methods of saying, hey go forward with it but stop when you see here or slow down… it’s the old traffic light issue of how you manage this but it’s gotten a lot more scientific than that. Especially with the number of seismic arrays that they have now to really check and see what’s going on.
As far as my involvement here, I’d really prefer that the technology go in the area of the carbon usage. I know there have been some breakthroughs, I think MIT and a couple of universities have actually come up with way to make carbon fiber out of CO2. Which I think, even if it requires a little more energy, might be a better way to do this than just trying to put it in the ground. Alternately, you could use it in the petroleum industry but we’re gonna need to play this out and really be considerate of what we’re trying to do and what we’re trying to prevent. So that’s basically what I’ve done as I’ve just looked at it from a distance.
BW
Gotcha. Okay, let’s shift gears here just for a moment to talk about the completion diagnostics in general. If I were to hand you an exploration well and a modest budget, in a relatively virgin area that you and your organization are working in, for the first time, you’re not intimately familiar with it. What completion diagnostics would you be inclined to incorporate into your completion program?
GK
Just about everything under the sun that would identify the best areas of that formation, the sweet spots, if you will. Well, in the realm of engineering, we have a pretty good handle on how to build a well for a given set of conditions. Now, we often ignore details of formations which generate and house the hydrocarbon reserves. We do one measurement and then we seem to be through and we base all of our computer models on averages or estimates or data that’s probably older than the youngest person working there. So what I would do here is, I would assemble a team of geoscience and geomechanical experts first. I’d try to get local people who are familiar with wells drilled in that area and the effect that other operations would have had there. I’m not going to leave out the environmental side, I don’t minimize that at all but we need to plan… probably going to be off the pads… and plan the traffic, the other things that allow us to keep operating without infuriating the area around us on a you know public basis. This team, as soon as they are able to describe the better parts of the formation, then we could move in and then instrument the wells. Take one down with maybe fiber optic in it, I know it costs about a million dollars more but The information that you can get from that from the pressure measurements, the temperature measurements, and of course, distributed acoustic measurements.
That’s extremely valuable information. And then instrument your offset wells to let them know or to let you know when you’re fracturing, what are you seeing in terms of fracturing, shadows, stress shadows, breakthroughs, actual hits, these rogue fractures that can take off from really, when hydraulic diversion fails. That’s only good at the wellbore anyway, so what’s it going to do when it gets out in the well? We need to understand how fluids, including fracturing, how those fluid movements work within that formation. I’d also make use of the vendors and labs because these people work for everybody and, although I know that it’s a nondisclosure deal, the learnings creep across the lines just without all the names and locations attached but we all learn from those things. And that’s what we have to have to get that out. That’s what I would be doing, I would get a good team of people together and run it.
BW
Sounds good. Well, speaking of some of these newer technologies, what are some of the most promising or field technologies, not necessarily just completion diagnostics, that you see on the near horizon?
GK
Current technologies… I’m going to do this not exactly what you asked. I’m gonna give you some current ones that are maturing and then look out into the future. So current technologies that are growing into a level of great science. In other words, they’re becoming mature, include pressure evaluation with sealed wellbores, distributed acoustic sensing, how you monitor offset wells, how you determine where your depleted areas are within a well before you start a refrac campaign. And, of course, after you get all that done, then moving into the future now, and I’m going to include learning as an emerging technology. I know that everybody gets educated in universities or out in the field. Personally I like both of those things and favor out in the field better than some of the universities. But the problem there is that sometimes we get so involved with computers, that we really don’t get to the point where we understand what all these assumptions that we’re making and averages. It’s really become a home for computer models that created design and perhaps without the full understanding of the model operator as to what those assumptions and averages mean to the outcome of that computer model. So let’s take a moment andd just remember here that these formations, most of the sedimentary formations, they were laid down millimeter by millimeter over millions of years and the variation from top to bottom side, the side in a given formation is huge. Then you have the other factors that are coming in there of faults, and bedding planes, and all of those things that interrupt your flow or react with your pumping fluid.
We need to understand those. Now, I see that we need a lot of more understanding of geomechanical issues, just because I was pretty ignorant of that and now I’m a little less ignorant of that, but I know how important it is. And I’d like to see us stretch our learning and spread out… actually learn how to be more than just specialists. And you can probably tell that I’m a curious generalist and I don’t specialize in anything at this point. But it’s been a wonderful ride here and I see some great instrumenting and automating things coming on. But let’s understand the basics of the well before we get too carried away.
BW
Good point. Good point. Well, we promised to keep this interview relatively brief and concise and you’ve done a great job of that. I can’t help but ask a question. Just a personal question. What in the world was Amoco thinking when they closed down the industry’s flagship Technology Center in Tulsa? Would you explain that to me?
GK
That’s a good question… I’ll duck it a little bit but I don’t criticize BP. They had their hands full of creating one company. Amoco research had a fabulous track record for applied inventions, including fracturing, sidewall coring, CO2 flooding, lightweight cement, antiwhirl bits, all of these things, and then a training program that was really second to none. Now, the best part of Amoco research is still here. It’s still with us, it’s people.
BW
There you go.
GK
And basically, I want to kind of give a shout out to folks like Ken Nolte, who has gone, but Mike Smith, Larry Bridge, Jim Lee, Henry Nickens, Tommy Warren, Phil Pattillo, these were absolute giants in the industry and wrote the book on how to do everything from fracturing to artificial lift, to actual well design, etc. Those folks are still out there and what they have written, and what they left behind, is a darn good foundation. So, I was sorry to see the research center closed. I’m happy that the people kept on giving, that’s the key.
BW
Well said and you are definitely one of those key people. I remember, I still have your quality control handbook… Frac Job Quality Control. A lot of those things that came out of the Amoco experience so you’re exactly right, those people are still active and key contributors in our industry, including yourself. George, it has been great and happy to see that you are staying very, very active. I envy your hacienda there and the Hill Country, your barn dominium I’m gonna have to …
GK
Barn dominium. And we love it.
BW
Well, thanks so much for spending the time with us and we look forward to bending your ear and learning at your feet again in the future. So, thanks for joining us today and have a great, great week.
GK
Thank you very much.