Looking For North Sea Oil in Spain

How can studying rocks in Spain tell us where to drill for North Sea oil? Durham University PhD student Jo Morris explains to Meera...
27 September 2009

Interview with 

Jo Morris, Durham University


Jo -   Basically, I study some fluvial rocks out in Central Spain, which are very similar to what they're trying to drill for oil in the North Sea, so I can go out to my field and try and map them, log them, capture the different characteristics about it and then I come back to the UK and have meetings with the companies that are sponsoring my PhD and so let them know what's going on out there.  It helps give them a really good idea of what's going on in their reservoirs because if you think about it, when they drill, they only get a 10cm core, and from that 10cm core they've got to predict what's going in their reservoir that's say, five kilometres wide.

Meera -   Now why does looking into the rocks you're looking into in Central Spain help them understand the ones in the North Shore? So why are they similar and how can analyzing this help them predict with the right areas to dig?

Oil RigJo -   Okay.  So it's a really good question.  My rocks out in Spain are really good analogies for the North Sea because they're deposited at the same time.  So if there are any climatic effects on the deposition of those rocks, the climatic changes would have been ocurring at the same time for both the rocks deposited in the North Sea and the rocks deposited in Spain.  We're also in a tectonic basin - so with rifting, active rifting basin and all these sediments are being deposited within these basins.

Meera -   How does understanding the rock help people know where to dig?  So what do you need to know about a rock in order to know if there's going to be oil underneath it?

Jo -   Basically, the simple equation for finding oil in the North Sea and the reservoirs is you need to find sand.  That's where the oil's going to be.  So about 30-40 years ago when they started drilling there, it was quite easy for them because it was- the reservoirs were all sand.

Meera -   So is oil always under sand everywhere?

Jo -   No, it's not always in the sand.  You can get it limestones as well and things like that, just primarily the reservoirs that I know about in the North Sea and the reservoirs that they've been trying to drill into.

Meera -   I'm sorry I did interrupt you there.  So, primarily they need to look for sand, what then?

Jo -   In the case of my research, they need to look for sand, before I get shouted at by all the other geologists looking for oil in other reservoirs!  But yes, so if you think about a river on a flood plain in a modern day setting, the river flowing through the system is where the sand's going to be deposited.  But we've also got a flood plain that that river is flowing in through which where the muds are and that's not where you going to find oil.  So over time that river will avulse over the flood plane and stack up and build, so that sand is shifting throughout the system over time, and that's what my rocks have been doing in Spain and I'm trying to map and figure out, and by doing that we can then go back and look at the reservoirs in the North Sea and hopefully try and predict where that sand is, much better.

Meera -   So by finding where the sand is in the Central Spain rocks, that can help them create essentially a type of map of the North Shore rocks and then know which is the correct part to dig in?

Jo -   Yeah.  So what the people working in the oil industry would do is probably drill a couple of cores within their reservoir and from that 10cm core then try and build up a model, a 3D model of that reservoir.  And the reservoirs can vary in size but usually they're sort of 5 to 10 kilometres squared and on also vertical distance as well to create the volume, of course.  So what we try and do is we take what we found in Spain and put that information into the 3D models and in the 3D models, we have rivers flowing through and we have the mud plains in there as well.  And it's all about trying to predict the volume of sand and, therefore, the volume of oil coming out as well.

Meera -   So how has it gone so far?  Have you actually - have they been able to find some oil in the right places yet?

Jo -   Yes.  So I'm actually only towards the end of the first year of my PhD so I have been - I had a couple of meetings with the people that I worked within the industry and trying to hand over the information.  I've been on fieldwork in collected my data so I'll actually be analyzing that over the next year.

Meera -   And how beneficial then is knowing this for the oil industry?  So, I mean, obviously, they have to wait for this data so that's losing them money but then, at the same time, it's going to help them not waste money in digging in the wrong places.  So how would you and them combine to balance that out?

Jo -   It's just a mixture of trying to drill for oil in the short of period of time.  Obviously, the industry is based on an econo - it's all about money basically, an economic potential.  They obviously do have to wait for my data; but at the same time, they've got other experts in the industry.  They have other people working on things like this as well and they're always getting the information fed through, and they just, whenever they have to make a decision, whenever it's time to drill, they just use the data that they have at that point.

Meera -   What about the option of not telling them anywhere to dig and that way they can't and then we can solve the whole oil-fuel issue?

Jo -   A lot of people do ask me this sort of question.  They do wonder why you're working in the oil industry and things like that.  And you just sort of point out to them that everything is based on the oil industry.  If the - chair they're sitting on, if it's made from plastic, it's based on the oil industry.  The cars they drive to the supermarket, the food that they buy and eat from the supermarket--all is produced from the oil industry.  So it's not as simple as completely shutting off because it means we'll be going back to the Iron Ages and driving around on horse and cart and things like that.  So it's finding new ways of creating energy and lowering the amount that we use in the oil industry; but it will never go away.


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