Drill Strings for Dummies

We often make the point here at the Antisocial Network that if you want information, you ask someone who knows the facts. You don't ask your dentist how to replace a sewage extractor pump, and you don't ask the guy who mows your lawn how to do a root canal. Does that make sense? We think it does... but asking self-appointed "generalists" myriad questions and paying them for their half-assed answers has been the business model of more than one internet website, in particular eHow and WiseGEEK.com. Here to prove our point is communications degree-holder and former pizza-joint owner Keith Koons with his take on the immortal question, "What is a Drill String?" for WiseGEEK nice site AboutMechanics.com.

As we do in questions related to the oil industry – because that's who uses drillstrings – we went to the oilfield glossary hosted by Schlumberger, where we found this definition:

"Drillstring: The combination of the drillpipe, the bottomhole assembly and any other tools used to make the drill bit turn at the bottom of the wellbore."

Pretty succinct, eh? Well, that sort of concise definition doesn't fly at sites that have a minimum word count. No, Koons had to come up with a lot more words, and he did; topping out at more than 425. Keith's problem? Not all of them were... ummm, right? Some of his prose was a little off the mark, such as

"A drill string is a tool that is used for boring deep holes into the ground in order to locate and extract oil or other resources."

Well, according to the oilfield glossary (and our in-house expert), a drillstring is an assemblage of tools, not a single tool. The drillpipe itself comprises hundreds of 30-foot lengths of threaded tubes. Koons went further afield to tell his readers that,

"Mud also is injected down through the drill string to help cool the drill bit while it is in motion and to soften the surface that it is boring through, lessening the chances of an improper cut and increasing the overall lifespan of the bit."

No one our staff petroleum geologist knows has ever heard that crap about how mud is used "soften the surface" of the rock encountered by the bit. There is, of course, more:

"An average drill string extends 15,000 feet (4,572 m) into the ground when assembled on land and up to 30,000 feet (9,144 m) or more when constructed offshore..."

We have no idea where Koons came up with these numbers, but we would point out that only a small portion of offshore wells are more than 30,000 feet deep, so his "average" is rather unlikely. And the notion that a drillstring is "assembled" is... rather strange. Equally strange is Koons' claim that,

"...the components within a drill string are constructed...what is referred to as a stand. Each stand is then lowered into the ground before drilling commences, in order to ensure that the drill always remains within perfect alignment."

We have no earthly idea what that rubbish means, but we can point out that a stand of pipe is not "lowered into the ground before drilling commences," it descends as drilling proceeds. And the perfect alignment business? Who knows: maybe he's thinking of stabilizers.

Anyone who depends on the kind of crap barfed up by our Dumbass of the Day for information pretty much deserves to be ill-informed.

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