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Thursday, May 20, 2010

Guest Column: The Gulf Oil Spill

Hi all! My cousin Kyle, who is awesome, is an oilman. Not a Texas oilman, exactly -- more of an Alaskan oilman. He also happens to work for BP. I asked him to give us his take on what happened in the Gulf of Mexico recently, when eleven men died trying to bring us fuel and plastic products and a potential environmental catastrophe was unleashed. Here's what he had to say.

It's been a very emotional month for most BP employees. What happened on the Deepwater Horizon and the subsequent spill will have far reaching effects for every single citizen - politically, environmentally, economically. The science and technology that is required to drill in ultra deep water is both amazing and immensely complex. It's difficult to describe, but the cumulative scientific knowledge and skill required to do this is second to none - this is NASAstuff.... not outer space, but inner space exploration. It is extremely difficult and it is very dangerous work. If anything, the public is not getting a crash course in the risks we take to "fuel" our life styles. There needs to be honest and open debate about the risk / rewards of the life styles we lead, because the Gulf of Mexico is a very prolific hydrocarbon basin and our most important source of domestic oil, but it also contains some the richest bio-mass and bio-diversity in all the known oceans.

The sequence of events is still not clear, but in most accidents like this there is a cascading string of events that ultimately lead to catastrophes. In all operations in BP safety is always first. So, imagine the reaction of all the BP employees when this happened.... the safety culture here is very deep and very real. When planning for deep water drill holes we try to anticipate and mitigate all the known and typical problems we experience while drilling including the dreaded blow-out. This was a shocker to me.

Known: There was a blow-out. First, you have to understand the pressures involved in deep water drilling. Pressure is the key and its what you need to control - it will kill you if you don't and it will kill you fast. Controlling pressure is a balancing act of sorts and very complicated, but while drilling we use weighted muds to hold back the pressure. If the mud is too light - hydrocarbons will enter the well bore at higher pressures and you get a kick. If you don't control the kick and it gets away from you a blow-out can occur if the blow-out preventers don't activate. If the mud is too heavy, drilling fluids can leak off in the the rock formations. If you lose too much fluid, the weight of your mud column decreases and again hydrocarbons can enter the well bore to create a kick and a blow-out can occur. These are the basics and it's important to remember.

Known: The Blow-Out Preventer didn't operate as designed. This is tantamount to having the wings fall off a jet liner. Wings are not supposed to fall off airplanes.... but in rare events they do. The 48-ft 450 ton BOP was designed to withstand and bleed off a 15,000-psi kick. If the BOP was compromised in some way, this pressure rating could be much lower. From what has been made public, the pressures experienced on the deep water horizon was at a minimum of 6000 psi moments before the blow-out.

About BOPs. The BOP can pinch or shear almost anything to prevent a kick reaching the surface. However, most BOPs cannot shear drill collars and some specific tools (I don't know much about this BOP). When running drill collars and tools across the BOP, pressure is monitored very, very closely and the mud is well circulated and circulation rates are observed to make sure there are not abnormal circulation rates which can be an indication of a kick. Also, most BOPs are in a default closed position - deadman trigger so to speak. Hydraulic pressure is used to actually keep the BOP from closing shut. Why? If communication is lost with the surface and the hydraulic pressure drops to the BOP, it will automatically close and shut in the well. In this case, the BOP might have been compromised. It is critical to the investigation to retrieve the BOP to see why it didn't prevent the release of oil.

Known: This blow-out DID NOT occur while drilling. Drilling was completed and the crew had cemented the last section of casing called the completion. Most exploration wells are plugged and abandoned after the evaluation - this requires the hole to be cemented-up and properly capped. At this point a well has no more utility. This particular well, however, was a very prolific producer and we chose to complete the well and put it on a long-term production test. The well was being prepared for a sub-sea tie back to a nearby existing production header on the sea floor. So, rather than cementing the hole, the well fluid (remember the drilling mud) was being displaced with sea-water. This is standard procedure when preparing a well for production as the drilling mud can damage the productivity of the well.

Speculation: The crew of the deep water horizon thought they were dealing with a stable well. Clearly, this was not the case. The entire well was now completely cased - drilling activity was over. Then the wings fell off - something went terribly wrong.

Speculation: Blow-out occurred so quickly the night tower crew didn't know what hit them. If they knew they lost control of the pressure below them, they might not have had time to react. A blowout is the uncontrolled release (kick) of crude oil and/or natural gas from an oil well after pressure control systems have failed. Blow-outs are violent and destructive. As the gas moves up hole the pressure decreased and the gas bubbles in the column expand and accelerate. Near the surface the rate of gas expansion can reach super-sonic speeds. The gas release at the surface will create a gas "wind" which can destroy equipment and kill. The wind of methane gas at these pressures could be as fast as 300 mph!!

Speculation: The gas somehow got into the the drill-string. The most plausible theory I've heard is that the final string of casing collapsed around the drill pipe forcing fluids up the drill pipe and through the last string of casing to the surface. Did the cement fail? Did the cement disaggregate methane hydrates? Was the casing not to spec? How this could happen is unclear, but this would be a very, very rare event given the stage of the operation they were in. Perhaps, the weight of the sea-water in the well (the drilling mud was displaced) wasn't heavy enough to keep hydrocarbons from entering the now completed well. It's hard to really say.

Known: In the end the BOP was compromised somehow and could not prevent the blow-out. Clearly, if failed to shut all the way.

This is really all I know. I'm not going blame any one company for this. As the operator of the well, BP is responsible for the clean-up and will need to provide answers to the public. In the end, it's my hope that logic, cool heads, and honest debate can occur, but at this point I don't expect more than political theater and finger pointing.


Jen speaking: I'd like to hope that we can go a little farther than that and talk about our fondness for petroleum products, as well as alternative sources of energy. As of right now, nobody has come up with a better idea, and I expect offshore drilling will continue. We need to think about how much of that we want to do. And let's not forget that eleven families are without their fathers, sons and brothers today. People die to bring us oil, and not just in war zones.

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