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Oil rig tools became copper plated!

June 3, 2008

During a recent petroleum drilling project, some of our tools used in the hole became copper plated. We have never seen this before. We don't use any additives containing copper sulphate, the pH is kept between 8.5 and 9.5 and there is is no applied current. Some of the grease used as a thread lubricant for our drill pipe does contain copper metallic flakes, but there is little excess of this grease leaked into the system -- most is trapped in the threads. We pump 'mud' down the drill pipe and have a positive displacement revers pump ( a 'mud motor') along with some electronic devices designed to measure magnetic azimuth and inclination in the string. The 'mud' exits the drill bit and carries the pieces of rock broken by the bit up the hole outside the drill pipe to the surface. We could have had a current leak from the electronics but had no indication of this. We do use a fairly salty solution in the 'mud' that includes 6% by weight NaCL and KCl.

Anyone ever heard of this or care to put forward a theory of how this happened? It appears that the plating (at least upon the shinier surfaces)was quite efficient even for just the few hours the tools were submerged.

Oliver Coker
none (Petroleum Drilling Engineer) - Houston, Texas

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June 5, 2008

I have some theories.
Can you show pictures of all of the external pieces?
And then show and separate internal pieces used?
The holes that were drilled, what were they first drilled with? Or, is this the equipment used to drill the initial hole first?

Rob Coffie
Warren, Michigan, USA