Bill Abriel, SEG 2004 Spring Distinguished Lecturer, delivered his talk on ‘Earth Model Complexity and Risk Description in Resource Exploration and Development’ in Calgary on April 26, 2004. Based on the feedback that SEG received, Bill’s lecture has been received very well, not only in Calgary, but at all the 32 locations around the world. Bill was quite encouraging to our request for an interview and this was conducted before he delivered his Distinguished Lecture. We found Bill soft-spoken, cheerful and very enthusiastic and responsive in answering our questions. Following are excerpts from the interview.
Let’s begin by asking you about your educational background and your work experience.
Certainly. I was at Penn State as an undergraduate in the Geo Sciences in the Geophysics Division. Then I went to Graduate School and got a scholarship from NASA. So at Penn State University I received a Master’s Degree in Geophysics. From there I went to work for Chevron Oil Company and that’s where I have been since. So, for these 25 years I have worked mostly in the Gulf of Mexico because it was an attractive spot. People asked me where I would like to work and I thought the Gulf of Mexico would be the one place that we could really make a difference with lots of opportunities. I think that is still true to this day. I also worked a little bit in California in the Research Lab and then back in Operations Gulf of Mexico, then Australia for a little bit and now in Northern California. I’ve had lots of exciting work, mostly in Operations trying to stay on the leading edge of what is going on geophysically.
So, what continued to inspire you about your career?
Well, that’s an interesting question. You know, I am really fascinated with the concept of Geophysics and I enjoy it so much. I just can’t think of something else that I would rather do.
Bill tell us about some of the exiting moments in your professional life.
Sure. One of those exciting moments was the first day I arrived in New Orleans from graduate school and I had a little trailer full of computer cards. I finally found a place to park, and went into the hotel and then I couldn’t go to work the next day because a hurricane blew through the area. And I thought -Yeah, this is as exciting as I expected it to be in the oil business. Another truly exciting thing that occurred was working on our project in pre-stack depth migration sub salt. We put all our efforts and reputations into one particular project earlier on and it was really interesting. We put an awful lot of effort, money and time into it. Then we matured the prospect and drilled the well. It was great when that well came in and it was a big day for us, because then the opportunity for us to use PSDM was suddenly opened up. And I think the third exciting moment was when I received a letter in the mail inviting me to be a distinguished lecturer for the SEG.
Wonderful. So, Bill how does it feel, after spending so many years in the industry? Is it a sense of relief now – would you like to take it easy? How do you feel?
Well, you know this is one industry you simply will not ever take it easy in. I don’t think that will ever happen. No, everybody is going in a blaze of energy because there is just no way that you can ramp down in this business – it’s too energetic. It is the most exiting thing I have ever seen. It took about 5 years before I really felt and understood what I needed to do. Then it took about 10 years before I could actually do it and about 15 years before I ever found out if I was any good at it or not.. So after 20 years I am starting to think, maybe I know something about how the business really works and now at 25 years I am ready to start making a difference in the profession.
Over 25 years in the industry it has been fascinating to see the changes. The behaviors within the institutions are quite different and very positive. Plus, the internationalization of the business is really something. With the cross cultural elements of the way that we work, we have got to be the most international profession that I can possibly think of and I find that really rewarding.
To be a successful geophysicist, what skills does an individual need?
In my opinion I think that the biggest thing a person needs to have to grow in our type of business, (the oil business, environmental, groundwater, mining) is inspiration. You’ve got to be inspired to really want to do something. Secondly, enthusiasm and optimism, If you are easily discouraged – if you can’t get up after being knocked down, this business won’t work for you. I think that is a real issue for us because we get knocked down a lot more often than we would like. We are supposed to predict and often our predictions don’t come true. Also critical are skills in geology, math and computer sciences and the physics underlying what we do. Then also, certainly enough business sense to stay connected to the investments plus personal and team skills, because none of us works alone.
Oh yes, you need to be a team player. Certainly. A perceived trend in the seismic oil and gas industry is that oil companies are gradually shifting their operation emphasis from exploration to production. Is this true for your company?
We see swings periodically in exploration and exploitation. Certainly the process of trying to grow the company on a basis of exploratory opportunities has always been something that everyone has interest in. I am truly amazed at the size and the scale of the exploratory projects that we now execute. There is, of course, a big emphasis in areas of deep water. That is an enormous investment. You see a large number of people putting a lot of money into large projects for exploration. In Eastern Canada, Exxon and Chevron Texaco have invested 600 million dollars in the last sale off Newfoundland. That’s certainly not a small project, and completely exploratory. So the question is, where does that trend take us? Exploration and exploitation have always balanced in my view and certainly we also see a fair amount of exploitation too. Some companies have been traditional exploitation companies – going into currently existing fields where the subsurface is not as well known and the idea is to make that grow. And, by example, the tar sands of Athabasca are another type of exploitation project. With stable prices and a little optimism plus the belief that the price stability will be there for some time, those types of projects are very, very attractive as well.
What are the areas of operation of your company, both inside and outside of the US?
Well, you know, I am going to be challenged. As this goes into print if I am not careful, one of our offices will stand up and say, “I can’t believe that you didn’t mention us!!”
Let’s start with Canada. ChevronTexaco is involved in the Canadian West here and have been for some time. It has long been a place of interest to us. The other part of Canada that is important to us, of course is Eastern Canada. with significant opportunities.
Then the United States. Of course we started there. The Chevron part of the company started in California and we are in, mostly southern California. Also the Rocky Mountain fronts and the interior US basins. Plus the Gulf Coast, where we have a substantial operation and always have. I certainly hope we always do because it is a never-ending source of technical progress. There is always something new coming on. In southern America, we are much involved in Brazil, predominantly off- shore, and Argentina and Columbia, and Venezuela, so that is pretty extensive.
In Europe, after combining Chevron and Texaco, we are a whole lot larger and more diverse than we were before. We are much involved in the North Sea. We are also very much involved in the Caspian and other parts of Eurasia. About the Middle East – Chevron was the company that managed to drill the first successful well in Saudi Arabia and we have managed to stay in Saudi Arabia with good relations since.
Africa is quite diverse. I don’t believe that we have our biggest investments in Northern Africa, but we do have experience in Sudan and also Chad. West African experiences go back quite a ways also with a combination of new projects on shore and off- shore, in Nigeria, Angola and the Congo. We are also involved in China plus a great deal in West Australia and then some in the Philippines.
So I am not sure what we missed, but here is an important point – I believe that 80% of the value of our Company is under the ground and can’t be seen. The geophysical predictions are critical to us in these fascinating provinces.
That is quite a comprehensive answer you gave, Bill. Good. In your opinion, how is technology changing the oil and gas business? Do you believe that new geophysical technology holds the promise of extraction of more information for characterizing the reservoirs?
Yes, I am very keen on that. If we look a little bit over the years about what we have done and what we have seen I think we find from experience that the earth is very complicated. We have simple thoughts about it, or at least we try to make it simple. We prefer it to be that way but it is actually quite complicated in both scale and properties. In response to this complexity we’ve developed some fascinating and sophisticated geophysical tools, and I think the answer is that we are still making progress. When we start a project in a particular geographic spot, we know that we don’t know enough about it. Yet we predict results and find out more over time. I think we are blessed with the fact that we have people (clients) who want to know desperately what’s going on in the sub-surface and the opportunity for us to be working there is just great.
How much emphasis is being laid on the R & D in our industry and how much is it helping now?
Good question. I have my personal opinions, but it is not my direct line of work to identify R & D investment levels in our business. On the other hand, one of the observations that I have when I speak to people in the SEG, especially the workers trying to make some progress on research, is that we just don’t quite understand why R & D continues to shrink in our business upstream. I know the explanations have been put forward. I understand the drivers and other people do too. But we continue to ask the question, “why is it that if this is a multi-trillion dollar business world-wide with so many unknowns, R & D continues to be less and less of an investment?” I guess, I am still a little mystified about that and I find that most people are as well. So I am really curious about where this is going and what the answers are.
We’ll see that down the road. Let’s come to pre-stack depth migration. We know that it is a powerful technique for imaging the base of salt and underlying sedimentary formations etc. So do you think that we are in a position to address this at present?
I have been pleased to be able to work with pre-stack depth migration and I am fortunate that the company that I am working with is one that makes a great deal of use out of this technology. Certainly there are some plays that clearly lend themselves to this type of work, but it sure is a tricky business. It’s not just getting the velocity right, but we’ve got huge problems in areas that relate to noise, problems that relate to signal/noise, issues that relate to whole dropped out image zones. It’s a challenging technology because the issues are hard to describe to people. The fact is that it’s not a clean image everywhere and because it’s not a clear picture, how to let people know how poor it is in one place and yet good in another. Sometimes we don’t know the answer ourselves and then to communicate this to other people is even more of a challenge. As a result, we are trying to use those communication tools of the trade to be sure that folks understand that.
But what about non-subsalt? Are we ready to go with PSDM everywhere? Well computationally we are certainly a whole lot further along. I’d argue probably that you and I could go out and buy a machine and some software and we could probably pre-stack depth migrate 3D data today. So I don’t think the question is the capability, I think the question is the cost / benefits. That’s really a big issue for all of us in PSDM. It’s the amount of time it takes to continually work and work and work and work to iterate a solution you are really happy with. So I think the more interactive that we get with pre- stack migration the better off we are going to be. Not everybody can work that way and not everybody can afford it. Not all projects are ready for PSDM.
I think at least some four, five years ago we heard of Salt Proximity Surveys that have been conducted to image the flanks of the salt dome. Do you think that is the way to go?
You know I got involved with Salt Proximity Surveys a long time ago and they really have been moderately changed over the course of time. The whole idea is that it’s a beautiful refraction technique. We even get ourselves into directional information, to be sure that the waves are coming from the direction we expect and then point back to the salt in it’s location – a very powerful technique. But it can get confusing as salt is not just a lumpy body, but rather complicated in 3D. For example, salt can squeeze up faults and create “wings’.I don’t think there is any question that we will continue to work with Salt Proximity Surveys and more bore hole data as time goes on. My perception is that we will find a way to instrument bore holes and be able to shoot borehole seismic data with the surface seismic data. I believe that’s probably where we will be in 5 years or so.
Some of 3D VSP configuration?
Well, yes. We need as many ray paths as we can get, don’t we? And this provides another set of ray paths we currently just don’t have.
Lets get back to the pre-stack depth migration algorithms. People have been talking about the Kirchoff and shot profile type of algorithms which are better suited for land and a common azimuth algorithm better suited for streamer data. In your experience, what do you recommend?
Well that’s a great question. You know, there was a good paper presented last year at the SEG Conference that tried to, I think lay this out, suggesting that there are in fact different types of algorithms and procedures. My perception is that if you look at say Kirchhoff, Gaussian Beam and wave equation, that’s three fairly major techniques for imaging. And if we ask “what is it that we are trying to solve?”, I think that there are a combination of issues there. One of those is velocity, another is trying to get the rays to behave themselves in a rational manner so it doesn’t cost us a lot of money and thirdly, trying to get the amplitudes right. And I think that probably if you take those three algorithms and you try to match them up against three objectives, I think we see the reason that one might be more suited than another. So, for instance we may find that velocity is a little bit easier to deal with when you are doing Kirchoff work because you can iterate your way through a little bit faster, you can reverse the algorithm and make it into a velocity analysis tool. Alternately, if you are trying to work only on the issues of the precision of the amplitudes and velocities are fairly simple, then perhaps wave equation would be the algorithm you prefer to choose. If on the other hand you have a sort of a middle ground, and you are trying to both get velocity and pull things together, be interactive and get the amplitudes rights then you might choose an algorithm like Gaussian Beam. I have seen organizations employing all three for different reasons and I think that’s a question of efficiency on addressing the problem at hand.
Do you think it is worth the effort time and money to go in for a pre-stack depth migration at this stage now?
I have been very surprised and quite pleased at how often our pre-stack depth migration work has revealed yet another complexity that we had not yet anticipated. You have to work pretty hard in order to use a sophisticated tool like that and you uncover a lot about the earth. Usually it is something you didn’t anticipate, some form of anisotropy or some geological knowledge pops out. Now on the other hand, there is the time and expense. I don’t think it’s so much an issue about the computer time, but getting the data and having the labor force actually working well enough to be able to sort the problems out.
I notice in your biography posted on the website, you had at one point of time in your career worked on 3D DMOs, so I was just wanting to get your comment on, do you really feel the need of a 3D DMO in the industry now?
That’s a good question. I think that the industry has probably started to move considerably away from 3D DMO, primarily because of the efficiency of pre-stack time migration. DMO was there to help us down the prestack imaging road so we could have a partial pre-stack migration. It certainly is interesting to remember the first 3D DMO because I remember Dave Hale had worked it out nicely. Dave was in our research laboratory and working on 3D DMO. David put the application together on a Cray computer. We got a project prepared and Dave said – “let’s ship the tapes” . I said okay but you know it’s actually a fairly large shipment, to which Dave replied – “that’s okay just go ahead and have them delivered to my office”. Well a truck full of tapes rolled up to the laboratory and I remember the telephone call from Dave suggesting his office was not big enough. Dave and the laboratory support team did a great job and the first 3DDMO ran on a complicated salt dome – perfectly. It was a major breakthrough.
Was it the 9 track round reel at that time or 3480s?
Those were 3480s – lots of them.
There is tendency in the industry to pull out 2D lines out of a 3D seismic volume to carry out AVO analysis. Do you think that’s the right approach? I would like your comments on this.
That’s a very good question. I’ve got some experience on that and because that’s true I’ll offer two answers to your question.
One of those answers is an experience that I had in working with people that I respect a great deal in West Australia where we didn’t have 3D seismic data but were working with 2D seismic data. The level of work and the expertise that went into that was incredibly high and I was very pleased to be involved in that. My feeling is that those predictions were quite good. There was variation and uncertainty but that seemed to suit fairly well for what we were trying to accomplish. On the other hand, I also was involved in another project in the Gulf of Mexico where we did precisely what you say, which is to extract the 2D seismic from the 3D volume. And in that case, we also processed the 3D seismic data and did it exactly the same so that we have a true 2D/3D comparison. The variation in dip was small but the variation in the reservoir reflectivity is large. And the reservoir changes horizontally very quickly – much smaller than the Fresnel zone. Because these variations are strong and the stratigraphy has a short correlation length, the 2D and the 3D AVO gave exactly the opposite answer. This was a real eye opener.
So what is the lesson? I suggest that if the 3D seismic data is available for us to look at, a real good measure of how well we are doing is to pull out that 3D migrated seismic line and then go get that 2D seismic line and process the data up to the stack and the migration. If we put those on the wall and then can’t tell the difference between the two it’s much more likely we’ll be able to look at AVO in 2D. On the other hand, if they are different I think that there is no chance that the gradient from the 2D would be of any value to us. So I see that as a simple test.
Let’s move on to reservoir characterization. Integration of data, integration of discipline is sort of a fashionable word these days, but I wanted your comment how much integration of data discipline is being really done in the industry these days.
I think it depends a lot on a combination of how quickly we are trying to work through the answer. There are one-day projects where we get a fairly simple view on integration. It’s a conversation between the professions. And that’s fine. That’s a critical form of integration. If it’s a one-month project, then I think that what we get is a somewhat higher level of integration, but less satisfying to our profession because we know that we should be able to contribute more. Then there are the one-year projects. And in the one-year projects the level of integration can be incredibly high. If we believe that the investment is worthy then the integration levels are in fact fine – except people in projects are impatient. Often we do not get the chance to scan the whole range of possibilities and that hurts our subsurface predictions. In fact, it can lead to some very bad investments. Geophysics in particular has very high value of information very early on in the integrated subsurface descriptions, and we need to keep pushing people to stop and listen to what it says.
You are quite right. Okay, let me ask you about the overall future of our industry; do you foresee a stable, smooth period ahead or do you see ups and downs coming our way?
It would be wonderful if we could predict. Well, certainly it’s been very interesting to see the continuous prediction of the demise of the oil industry every 5 years. That’s happened episodically about every 5 years and we don’t seem to be there yet. My prediction is that we’ll be here in the next 5 years also. If you said 50 years, then that’s a pretty long distance, about 3 generations away, and so it’s certainly more difficult to predict. No question it will be different. Published data from some of the larger Government institutions, large oil companies, etc. predict that our industry will eventually not be the primary energy supplier on the planet. That is undoubtedly correct, because demand will continue to outstrip our ability to supply at some point and we believe that time is fairly soon. Companies that are looking forward are looking at themselves as energy companies with solar investments, fuel cell investments, and hydrogen investments. But as to the oil and gas business, much more is yet to be done. As an example, gas that appears to have been stranded by long distances to market are slowly but surely making their way into the economic grid. The large projects that were put on hold a few years ago are now the projects that are coming forward. Plus the promise is not just of LNG trains but gas to liquids, and those opportunities look very attractive so subsurface geophysics will be in high demand.
Yes, with the continuous evolution of technology, I think we will always be in a position to extract more and more information as we go along, so I think that will continue and allow us to get more and more hydrocarbons.
Okay, so let me deviate from the technical part now and lets ask you, what are your interests apart from the science, what do you do in your free time?
Oh, free time – well, actually there is a little free time. I am really pleased to say that I have enjoyed working with my children. Working with human beings is fascinating and when you get a real close family relationship it is very rewarding. I have my 2 boys and my older girl plus my wife who teaches at the University and brings work home. We spend time discussing the law around the dinner table and it’s almost like having a second life. So I get a chance to get a break from geophysics that way.
Is she a law professor?
She is. She is teaching even as we speak and then she is also taking care of the boys at home. And the other interest that I have is in the sport of Lacrosse. I coach some in Northern California where we have an explosion of interest. So I coach at some different levels, but I don’t play. I used to do that but I am wise enough to keep off the field now.
We have a team in Calgary too.
You have a professional box lacrosse team in Calgary and we also have one in San Jose. Unfortunately San Jose lost to Calgary in the play-offs by 1 goal in a very close game. Calgary will be pleased to know that they won’t have to play Toronto who just lost to the Buffalo team. So the fellows from Buffalo are going to be here on the week-end of May 7th to play for the championship in Calgary and I certainly wish you the best.
Bill, just to sort of wind up, what words of advice would you have for younger friends in our profession?
Well, that’s a good question and you know that question comes around a lot. We are spending a fair amount of time on the Distinguished Lecture Tour at Universities where people are asking the question “Should I be involved in the business – what’s the business like” I think probably my advice to folks would be that if you are not interested in solving hard problems and if you don’t like excitement, then don’t do our kind of work because that’s what we do. It is predictive and because it’s predictive, you will find out how well you do. It’s putting pieces together – putting the puzzle together and trying to sort out what’s going on through using fascinating and sophisticated tools with wonderful people. I am so pleased to have been able to work in this industry and especially with groups like the SEG Professional Organizations that bind things together. I just can’t think of anything that I would design that would interest me more. So folks I think will find that out for themselves – but if you are not interested in excitement, don’t apply.
Good. Bill, thank you for giving us this opportunity and time to sit down and chat and we appreciate it very much.
Well thank you, it is a real pleasure.