By now, everyone has seen numerous expositions about what went wrong at British Petroleum’s Macondo 252 wildcat well. Every driller and every rig superintendent working in the Gulf of Mexico must know exactly what BP failed to do at various stages by not following standard operating procedures (or good oilfield practice) as it tried to abandon the well temporarily. Everyone in the oil business should know by now.
Then why is it that the current federal administration is declaring a six-month moratorium on offshore drilling in the Gulf of Mexico at water depths greater than 500 feet?
Answer: Politics and payoff to the left-wing anti-drilling/environmental faction that wants to skewer the oil industry, control energy and promote cap and trade. Never waste a crisis.
So, farewell to the jobs of 30,000 offshore workers and another 30,000 to 50,000 that service and supply the offshore industry. (These are my figures and may not be accurate to the last decimal.)
The stupidity is even greater than suing the state of Arizona for upholding federal law.
After gathering bits and pieces from the Internet, here is my list of what BP did and how it compares with my knowledge of standard operating procedures:
1. Having encountered — during drilling — over-pressured formations requiring 16 ppg (pound per gallon) mud to hold back the formation fluids, BP needed to case off (set high-strength pipe) the lower approximately 1,200 feet of hole. The upper part of the hole was already cased off.
To save rig time, BP decided to set a complete string of casing (7-inch and 9-inch combination) to the sea bottom rather than set a partial string (called a “liner”) up into the lowest casing (itself a liner). Standard operating procedure, particularly in the event of over-pressure, is this: Set a liner, with a tie-back top, to improve the probabilities of getting a good cement job, then set the tie-back string to the sea floor and cement that as well. That would give two barriers to downhole fluid movement.
2. Calculations showed that 21 centralizers should have been attached to the casing to assure all of the casing would be covered with cement. To save rig time, BP ran six centralizers. Standard operating procedures: Assure that the casing is well-centralized in the hole by running adequate centralizers.
3. To save rig time, BP did not circulate bottoms-up before pumping cement. That means it did not pump mud down the hole to clear out all cuttings and gas pockets and assure a clean shot-gun barrel well-bore for the cement. Standard operating procedure is to circulate bottoms-up by pumping at least one volume of mud in the hole and preferably one-and-a-half times the volume of mud in the hole. This was a huge mistake; the cement was probably contaminated with cuttings, oil and gas, and a good cement job was almost impossible.
4. After pumping cement, to save rig time, BP did not run a cement-bond log. A cement-bond log is a sonic tool that emanates sonic pulses much like an ultrasound at the doctor’s office. If there is good cement bonding between the casing and the formation, the response to the sonic pulses shows a distinctive pattern and is easily interpreted.
Standard operating procedure after cementing casing/liner is to run a cement-bond log and a temperature survey to show the top of the cement. This was the major failure of BP, because a cement-bond log would have shown that BP did not have adequate blockage below the 9-inch casing and remedial action would be necessary.
Failure to have a good cement job — and a barrier to the flow of downhole hydrocarbons — resulted in the migration of high-pressure hydrocarbons up around the 7-inch casing and into the space between the 7-inch and the 9-inch casing and from there to the sea bottom.
5. Some people say to save rig time BP did not allow sufficient time for the cement to “cure,” that is to achieve adequate compressive strength. Thus, it may have conducted a pressure test of the cement before it was sufficiently set and thus disrupted any cement bonding and facilitated the eventual leakage. Standard operating procedure, depending on the cement composition, calls for 24-to-48 hours cure time.
6. There is evidence BP did not set a locking plate on the sea-bottom casing hanger. Standard operating procedure requires a locking plate to keep the casing hanger in place. Failure to do so may be the reason the blow-out preventer did not work. Its function was blocked by the blowout of the unlocked casing hanger or other debris. (That is conjecture on my part.)
So, if I can obtain this scenario from the Internet and the newspapers, knowledgeable offshore engineers and drillers and rig superintendents must be fully aware of all of the miscues and have many more details in their understanding of events.
Thus, there is absolutely no reason for the president and secretary of the Department of the Interior to place a moratorium on offshore drilling so they can figure (out) what went wrong. This reeks — absolutely stinks — of political payoff at the lost-job expense of the people of Louisiana, and Texas — and eventually the people of the United States who will have to pay more for their gasoline and diesel and eventually transfer more of their wealth to foreign oil producers.
Those deepwater rigs are not going to sit idle for six months. They will depart for Brazil, Trinidad, West Africa, and the Middle East. The owners of those multimillion-dollar rigs are not going to let those assets become non-producing. They will go where they are welcome.
This accident was absolutely avoidable, and a one-in-50,000 event. If well control appears tenuous at any time, it is also standard operating procedure to set open-hole cement plugs and bridge plugs inside the casing, dumping some cement on top.
BP screwed up, no question about it. The administration is just making it worse.
Once again, politics trumps common sense.
Weldon Frost, a resident of Longboat Key, spent 37 years as an executive for Mobil Oil, overseeing approximately 60 offshore drills in the United States, Gulf of Mexico, Middle East, Africa, South America and the North Sea with no incidents.
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