The following post was written by a very bright friend of mine, Adelaide Calbry-Muzyka. Adelaide is currently working towards an MS in Mechanical Engineering with a focus on energy at Stanford University. I’m thankful to have the variation in perspective and welcome others to join our growing team of contributing and guest writers – just let me know if you’re interested!
As we all prepared for the International Day of Climate Action events this past weekend, I was learning about the source of the fuel that is a considerable part of the reason we need a Day of Climate Action in the first place. As part of an “Energy Resources” class I’m taking this quarter, I went on a field trip to the San Ardo oil field in Salinas Valley, CA.
Regardless of what we would like the future of energy to look like, the fact is that over a third of global energy use today still comes from oil. Oil on its own has a significant impact on the environment, of course – the carbon dioxide released when burning oil certainly contributes to global warming, and localized accidents such as oil spills can be detrimental to neighboring ecosystems. Ideally, this would all mostly go away in the future as we switch to greener energy sources. But in the meantime, what can be done to mitigate the environmental impact of its extraction process? What are oil fields like San Ardo already doing, and what could they do better?
First discovered in 1947, the San Ardo oil field is the 13th largest in California, and produces 11.4 thousands of barrels of oil per day. Two oil companies pump oil there: Chevron and Aera (a California-based joint venture of Shell and ExxonMobil, for those not familiar with Californian oil companies).
As far as I could tell, there are two main drivers for increasing environmental friendliness at an oil drilling site: money, and government regulation. The potential third one would be a call for greener action from shareholders, but that hasn’t seemed to be a significant factor in shaping oil companies’ policies yet (I’m holding out hope, though!).
Money
Many environmentally-friendly practices can also be wallet-friendly for the companies involved. Energy efficiency, for example, makes sense from all standpoints. San Ardo insulates its steam pipes to lose as little heat as possible, and it optimizes pressure gradients inside the oil reservoir to maximize ease of recovery.
More importantly, it runs a co-generation plant that produces 6.5 MW of electricity. This is a pretty simple system: basically, San Ardo needs hot steam to inject into the ground to loosen the oil and be able to pump it up. But producing steam just for oil recovery isn’t very efficient; there is a lot of heat lost through the earth when the steam is at the bottom of the oil well. So, part of the steam is used to turn the turbine of a generator before being injected into the reservoir. This increases the efficiency by 80%, and it allows San Ardo to produce two-thirds of its own electricity needs on-site, and even sell the excess back to the nearby town.
That said, some fairly obvious energy efficiency considerations could still be put in place. San Ardo currently holds two separate co-generation plants – two separate systems to drive turbines with hot steam – a process that would only get more efficient with the greater steam flow if the systems were merged into a single one. The problem here is that the field is owned by two separate companies, Aera and Chevron, and business competition has kept them from cooperating on this issue, despite the significant financial and energy advantages of consolidating work. Resolving this particular issue could only benefit all parties involved.
And although this would require greater study, the potential for installing solar panels amidst the oil rigs seems significant, given the weather conditions and oodles of open space above ground. San Ardo’s owners could sell solar-generated electricity along with the co-generated one; the connection to the grid is already there, they would make money from it, and there would be a little more sustainably-produced electricity in California.
Government Regulations
Even when some environmental practices are not justifiable from a purely business viewpoint, they are still required by state and federal standards. I’m an engineering student, so I don’t have as much of a grasp on policy as some others would, but I do have a general understanding that the government doesn’t let you release just anything into the ground or atmosphere.
The treatment of water retrieved mixed with the oil from the reservoir, for example, is a large portion of the work done at San Ardo. Every day, 60 thousand barrels of water are cleansed of petroleum-based impurities before being released back into the ground (compare that to the 11.4 thousand barrels of oils produced over the same time period). Hot gases are scrubbed of their sulfur content before being released into the atmosphere, reducing the risk of acid rain from hydrogen sulfide (H2S) and sulfur dioxide (SO2). These procedures, I would imagine, are largely a result of government policy restricting environmentally harmful waste, and are regulated by the EPA and, in California, by the CARB (California Air Resources Board).
What about us?
So what does this mean for us? Going back to my point about how oil consumption isn’t going to disappear overnight, we do want to minimize the impact of oil recovery while it’s still going on. This means letting oil companies know what they can do better – and there are two main ways of doing that. The first, of course, is through the government. If we keep letting our elected officials know what matters to us, they will push the government to set stricter standards, and that will shape the way oil companies are allowed to conduct business.
The second is through public opinion. I said earlier that environmentally-concerned shareholders haven’t been a big part of the reason for greener policies in oil companies, but I was only partly kidding when I hinted that this could change. People are increasingly taking a personal interest in the environment and climate change – just look at the magnitude of the worldwide 350 events last weekend.
We had significant interactions with only one engineer at San Ardo (an Aera employee), so I can’t generalize from his attitude or from the single field at San Ardo. But it was refreshing to see the level of genuine interest he took in our comments and questions – most of us were master’s students in environmental engineering, and were ready to (politely) call him out on a whole variety of issues. He was clearly extremely well-informed in his own field of petroleum engineering, but he commented several times that he would have liked to learn more about sustainable energy and the environment. The conversations we had were, I felt, educational for both sides. Even if a company is going to be drilling for oil, it might as well try to do so in as environmentally-friendly a way as possible – and that doesn’t seem like an unrealistic goal at all.