It’s always painful for me to jump back into oil-spill coverage. Been there, done that. Wrote a book about it. Learned a lot about petroleum engineering and then assiduously, compulsively, dutifully forgot it all.

The only thing left is a jumble of terminology: Annular preventer, blind shear ram, 3-ram capping stack, hot stab, negative test, cement bond log.

But now there’s news: Someone has finally been charged with a crime in connection to the oil spill (which answers the question I posed the other day). And it’s a nobody.

Or, more precisely, it’s someone that I’ve never heard of: Kurt Mix, a former BP engineer. The government says he obstructed justice by deleting text messages exchanged with his supervisor, including some sent during the critical “top kill” operation of late May 2010.

The news accounts, and the experts quoted therein, have tried to make sense of why the government would go after such a small fry. There’s speculation that he could provide information that would implicate BP officials higher up the chain of command. I don’t think anyone knows what’s really going on at Justice. Maybe even Justice isn’t sure what it’s doing.

The news reports focus on one of the texts, recovered by investigators. Sent to a supervisor the night of May 26, after the first two failed efforts to kill the well with mud from the top — the top kill — the text said, in part, “Too much flowrate — over 15,000...” This means the well was gushing more than 15,000 barrels a day, three times what was then the official estimate embraced by BP, of 5,000 barrels a day. Critics of BP say the company was deceptive throughout the oil spill about the flow rate.

I don’t know why Mix deleted the texts. That’s something the courts will deal with. The Chron quotes his lawyer saying he saved duplicates of the deleted texts, as required, and will be exonerated.

A couple of quick thoughts about this case:

Notice that the folks who caused the problem in the gulf (and it was a team effort from multiple companies) were also the ones who were trying to fix it. This was BP’s oil spill, and, under the Oil Pollution Act, it was also BP’s oil spill response — notwithstanding the sometimes exaggerated claims by the government that it was really calling the shots.

This arrangement created a conflict of interest. There was a structural incentive for BP to think not only about how to kill the well, but also about how to minimize its exposure to civil penalties. You had engineers dealing with an issue that was also of great interest to company lawyers. To this day, BP disputes the government’s official estimates of how much oil flowed into the gulf.

Rule one in a crisis: Measure your misery. Figure out how bad it is. But BP decided not to measure the flow rate of the well when the Woods Hole scientists were ready to splash a submersible and use the kind of gear deployed at deep sea vents. The BP explanation was that it was about to try to lower a containment dome over the leaking pipe and couldn’t simultaneously deploy the Woods Hole gear.

But the company also knew that it would be liable for the amount of oil spilled. Without getting too deep into what may be a highly litigated area, we can wonder if the company wanted to maintain uncertainty about the flow rate. (BP has denied this — and it has said consistently that the flow rate was irrelevant to its efforts to plug the well.)

But by not knowing the flow rate, the company may have hampered its ability to kill the well. The top kill didn’t work because it couldn’t work — it couldn’t overcome such a powerful flow of oil and gas. So maybe it was a complete waste of time (just like the ill-fated containment dome). According to the affidavit filed by the Justice Department , Mix and colleagues had determined that the top kill wouldn’t work if the flow rate was 15,000 or higher.

You have to remember that the top kill was the most dramatic moment of the spill to that point. BP’s Tony Hayward gave it a 60 to 70 percent chance of being successful. He had a gift for saying the wrong thing.

Government emails from earlier on May 26 (quoted on page 145 of my book, for which the endnotes are online) capture the nailbiting nature of the attempt to choke the well:

2:13: “So far it is a tie—the mud being pumped in seems to be

mostly coming out of the riser. We have not yet hit a tipping

point that indicates a killed well . . .”

2:24: “They seem to be having trouble outrunning the well

(pumping in faster than well can spit it back out). They have increased

the kill flow rate to 70 bpm [barrels per minute] . . .”

3:19: “The situation appears to be relatively steady. They have

pumping mud at 60 to 70 bpm for the past hour and a half (about

4,500 [barrels] total). There are no indications that things are getting

worse—but it is not clear that the kill has been (or will be)

successful . . .”

4:35: “They just closed off all mud flow and are seeing whether

the well will go stagnant. So far (4 minutes) the pressures are all

going down slowly (a very good sign—but not conclusive).”

6:11: “. . . the pressures (kill/choke and below BOP) starting

creeping upward . . .”

And when the pressures crept upward they knew it hadn’t work. They tried again in the evening, and then late that night Mix sent the email that he later deleted. His text, as I read it, may simply reflect what the top kill had confirmed diagnostically. Here’s the full text:

“Too much flowrate – over 15,000 and too large an orifice. Pumped over 12,800 bbl of mud today plus 5 separate bridging pills. Tired. Going home and getting ready for round three tomorrow.”

Hear the fatigue and despair there. Confirmed: This is 15K-plus. Won’t work. He must have known round three wouldn’t work, either.

The well gushed for another seven weeks. The flow rate was, the government scientists later determined, at least 53,000 barrels a day.