60 African Elephants

If you’re reading Ron’s blogs, you know he’s the go-to person for explanations about drilling and how it works.  Here are a few “bits” (yes, it’s meant to be a pun) of drilling info I’ve picked up over the years and in conversations with Ron.

1. It usually takes something like 10 to 12 hrs to trip pipe to the seafloor in these depths (>5100 meters).  All the pipe together is called the drill string and it weighs about 200,000 to 300,000 lbs.

Challenge:  Convert the depth in meters to feet and miles.  Send your answers using the comment function below.  

2.  STRAP AND RABBIT: Clear, eh? Joints of drill string are approximately 10 m long. Three joints are screwed together to make a stand approximately 30 m long (see photo). The first time the drill string is used on each expedition, we “strap and rabbit” every stand of drill pipe we use. The “strap” is simply using a very long measuring tape to get the exact length of each stand. This way we know how long the entire drill string is. The “rabbit” is simply passing something the size of a core barrel through every stand to make sure there are no obstructions on the inside of the pipe.  Got it?  Three joints make a stand.  Measure the stands with a strap.  Send a rabbit down the pipe.

3.  DRILL STRING WEIGHT: As usual, I learn new things every day (despite this being my 13th expedition). When I said the drill string weight was about 200,000 or 300,000 lbs, that was about correct for my last expedition that was in much shallower water. It’s actually more like 600,000 lbs! That’s about that same as 222 Honda Civics, or 130 Toyota Highlanders, or 60 African Elephants (bulls), or 2.5 Diesel locomotives, or 2 very large Blue Whales. All of this is hanging below the ship that is heaving up and down on the swells while the drillers drill and the dynamic positioning folks keep us on station!

Hello NSTA!  How’s the conference?


Photo: Stands of drill pipe ready to be strung.  Credit:  Bill Crawford, IODP imaging specialist.