What are the key factors that lead to success or failure in EOR projects?
Joop de Kok (JK): The success and failure is dependent on how much oil is left after the first stages [of production]. The steps [in the production process] are increasing in complexity, there are more things you have to be aware of, there are things you might overlook, things you just don’t know because you don’t have the information. There are more risks associated with EOR in general.
Mike Gunningham (MG): Generally, in an oil and gas project it’s about cost and how much additional recovery or production you get, and generally enhanced oil recovery is done at the end because it’s probably the most expensive way of getting the oil out. It’s something people look at when the price of oil is high, and people have been looking at it since the end of the Second World War because they thought the oil was going to run out.
Is there a benefit to companies investing in EOR earlier in the production life cycle?
JK: It has been done before, especially in heavy oil. There is no way, or hardly any way, you can produce just by drilling wells or by water injection. Also, it’s not very efficient to do it at the end of field life. For example, for steam injection, all the water you have put in before has to be heated, so that’s inefficient. The reason people do it in the end is because it’s very expensive and at the end of the field life it’s also the time where you know most of your reservoir, so your uncertainties are reduced. If you would start from the start, your risk and your uncertainties would be higher.
Is that why pilot projects are so common in EOR?
JK: It needs a lot of investment from the facilities side, so you want to make sure it works before you put it in the entire field.
MG: I was working on a major EOR pilot offshore, and we took a phased approach where we tested water alternating gas, where you inject water for a period, then gas, then water… and the idea is that effectively the gas is kind of loosening up the oil and it’s pushed up by the water. So that was done as a pilot in one part of the field so they could see if it worked and then they could expand it to the rest of the field.
How is digitalisation affecting ‘field uncertainties’ and, consequently, EOR?
MG: The old-fashioned computer simulator for a reservoir was something called a “Black Oil Model,” and effectively it just looked at oil, water, and gas in separate phases. Now, you can have models where you can see the chemical interaction between what you’re injecting and what is being produced.
JK: Also, there’s a lot more data collection, which gives you a better idea of what’s going on in your reservoir, which reduces your uncertainty, and increases the chance of a successful EOR project.
Do oil & gas companies see the opportunity in EOR?
MG: Absolutely. On the plus side for EOR is the fact that you already have invested in wells, in facilities, so you don’t have that big capital expenditure like you would with a new field. There’s an incremental cost, but if it can give you an extra 5% or 10% recovery, especially in the Middle East, which has big fields, it could be worth it.
JK: For smaller companies, it’s always a balance of the cost and the risk associated with the additional barrels, and quite some companies are looking into that, but the lower oil price put it on hold for a bit.
Tell me more about how the oil downturn affected EOR.
MG: Generally speaking, new projects have either been put on hold or move slowly. A lot of EOR work can still go ahead because it’s a table top exercise where you’re running simulators and looking for options, so a lot of companies kept that going, looking for an upturn in price.
Should companies invest in developing new EOR methods?
JK: For smaller companies it’s often a bit too risky. There are some companies that are really trying new things, but a lot of them prefer to look at others first to see if it really works.
MG: Going forward with the new technology that we have, with the advanced computing capability and a better understand of the physics and chemistry of EOR, we’re lowering the threshold where you could try it out and increasing the chance of success.
How will EOR’s role change as ‘easy’ sources of oil start being used up?
MG: It has gotten more and more expensive to develop new fields. The deeper the water, or of it’s in an arctic region, it’s just going to be more and more expensive, in which case EOR looks a lot more attractive, especially if you reduce the uncertainty, since you’ve been producing for years.
The costs of carrying out EOR are going to come down, we’re going to have a better understanding with the technology and the computing power that we have, so that if we try EOR it’s more likely to succeed, and that will start making EOR projects as attractive as developing new oil, and I expect in the future it will become a lot cheaper than trying to get new oil. The future of EOR is looking very promising.