After the 2010 Gulf of Mexico Oil Spill

In the Irish Times of Saturday 7th August 2010 Claire O’Connell has brought together a number of facts and points of view relating to ‘After the spill’. This accident cost human lives and caused injuries. The economic cost of the mistakes that have been made is enormous. The environmental damage is also enormous and its full extent will only become know in the course of time. Claire O’Connell points out that everyone, especially governments, must learn the lessons of the disaster. It seems deep-water exploitation of oil reserves is continuing in the Gulf of Mexico and elsewhere—it is to be hoped that those responsible are fully mindful of the issues.

In following the technical updates on the web I found it fascinating that at one point operations at a nearby well were stopped in order to take readings or make soundings at the MC252 well, which had been tentatively capped. As a professional mechanical engineer and an academic I have an appreciation of the high level of technology and the precision that are required to undertake deep-water drilling and oil recovery operations. It seems clear to me that in relation to this well there was never a lack of resources (as distinct from the question of willingness to deploy the resources) to do the job to the highest possible standards of safety. Undoubtedly and with hindsight, even from a purely commercial point of view, the risks were not properly assessed. Ultimately engineers and scientists must shoulder the responsibility and make the decisions in relation to the safety, including environmental safety, of these types of technical operations. Their judgement must never be over-ridden for the sake of making bigger or quicker profits. Undoubtedly too, with hindsight, regulation was inadequate. Lessons can and must be learned from this disaster, but, as Claire O’Connell has pointed out, there have been previous incidents from which some of the same lessons could have been learned.

Bad though this disaster continues to be, it could have been worse. This incident has made it clear to me that a much more serious incident of this general nature is capable of being produced. I feel that the the conclusion of Claire O’Connell’s article underplays the magnitude or seriousness of the lessons that need to be learned. It is not just that in this case everybody who should have been keeping their eye on the ball didn’t do so and will need to pull-up-their-socks, as it were.

Full public technical explanations are required as to what happened and precisely how the technical failures occurred. It is only in this way that provisions and procedures can be devised that are verifiably adequate to address the risks. How and why did the blow-out and fire occur on the drilling rig? Why did the blow out preventer on the sea floor fail to operate? Why was it not subsequently possible to close off the leak by means of the blow-out-preventer that remained in-situ throughout the entire incident? Could a scenario of the type that occurred have been foreseen by those who granted the licenses for the operations?

From following the technical updates on the web it has been clear to me that the engineers and scientists involved were struggling to comprehend exactly what they were dealing with. Even now it seems there is uncertainty about which areas of the entire well are subject to pressure coming from the reservoir. This is the nature of engineering and science: I recognise and accept that fact and I appreciate that many engineers and scientists have been working non-stop on the case. The job is not yet finished and there may yet be significant challenges in ensuring that the well is permanently plugged. It is important to make the technical questions and the conclusions reached public, e.g. through publication of comprehensive technical papers and reports. Such information must not be kept commercially confidential. It must be shared.

The technical issue that concerns me the most is that of dealing with the enormous pressures that exist in oil reservoirs deep beneath the sea and deep within the Earth’s crust. My own rough calculations suggest that the pressure at the bottom of the MC252 well must be about 936 bar, which is more than 900 times atmospheric pressure. In oil drilling and recovery operations this huge pressure is counterbalanced by the weight of drilling mud or crude oil within the well bore. However, in certain circumstances, which are still apparently not well understood, pressurized gas can fill part of the well bore and cause a, perhaps rapid, increase in pressure at the top of the well (of perhaps hundreds of bar).

Another technical issue of major concern, and the one with the potential for causing the greatest environmental damage, is the risk of opening up a large-bore communication between the oil reservoir and the surface. The entire leakage flow in the 2010 Gulf of Mexico spill had to pass through the bottom of the well bore, which had a casing of only seven inches diameter. From some of the quotations in Claire O’Connell’s article it might be understood and accepted that the configuration-controlled leakage from the oil well was perhaps less serious than the leakage caused by the splitting of a super-tanker. However, the occurrence of a large bore communication between an oil reservoir and the surface, or even between the reservoir and higher strata within the Earth’s crust could be very serious. It seems to me that these risks may need to be re-assessed in the light of the Gulf spill.

My professional opinion is that for the foreseeable medium term (say 100 years) it will be necessary to continue to drill for oil, even though the technical challenges are great. I believe this is a necessary part of the overall mix in attempting to achieve sustainability for mankind.

The 2010 Gulf of Mexico oil leak has been very serious and historians will make the assessments of its relative seriousness. The Earth can take the hit in the fullness of time: I feel confident about that, but I also realise that this resilience is of no consolation to those tragically or directly affected. I also believe it is right that commercial companies should be held fully accountable for their actions.