15:03 Mar 3, 2010 

I've selected Gillian's answer as the preferred option - in this case - but I will leave the grading/closing to the community because there are other answers that appear to be correct. Thank you all for your help!!!

13:34 Mar 3, 2010 

Thanks Gillian - it's actually a very minor item in a very large translation with little text actually relating to the drilling. Non-productive drilling seems generic yet descriptive enough if you want to make that a Kudoz entry :) please go ahead.

23:26 Mar 2, 2010 

If they are charging for this item, it is less likely to be the erroneous readings or the failed drilling operation as they would be the responsibility of the operator. The most likely option is the wrong location - specified by the customer, so he would have to pay - so I'd go for "unsuccessful drilling" or non-productive drilling or similar. I'd still add a comment to clarify. Maybe there is a hint further on in the text.

23:17 Mar 2, 2010 

Unfortunately it's not easy to get more info since I'm not in direct contact with the end client. The problem I have is that it is in a cost accounting table so they are "charging" for this item.

23:13 Mar 2, 2010 

There are at least 3 possibilities (as reflected by the current answers). Either the drilling process itself was unsuccessful (e.g. equipment fault) or it failed to produce the desired results (e.g. wrong location) or the readings were incorrect (less likely of the three).
Personally, I'd ask for more clarification. Failing that, use the most likely translation that fits with the other terms in the list and include a comment to the customer indicating that there are other possible translations.

17:57 Mar 2, 2010 

general subject?