The man behind The Friday Haggler, Neil Armstrong, Merlin ERD Engineering Director.
A reminder of last Friday’s Haggler
You’ve done all the modelling (torque, drag and hydraulics) for the well below based on drilling the 8-1/2” hole section with 5” drill pipe (24.23 ppf adjusted weight), however this pipe is no longer available (failed inspection) and you have to drill the section using 5-1/2” drill pipe (26.82 ppf), everything else remains the same. Without updating the models, which of options provided below would correctly describe the effect of the drill pipe change you would see when drilling the 8-1/2” hole section?
(a) Increase in pick-up weight
(b) Decrease in slack-off weight
(c) Increase in torque
(d) Increase in ECD (e) All of the above
Long Answer: The correct options were all fairly obvious except for the slack-off weight (SOW). At the start of the section the heavier drill pipe would definitely increase the SOW, whereas at the end of the section the SOW may be lower, however you would have to run the model to check whether the increased drag in the high angle interval has more of an effect than the increased weight in the low angle interval. A slightly tricky one!