User:Donshafer/Non-Productive Time

There are numerous ways of classifying and evaluating non-productive time (NPT). At its most basic, NPT is any time that the bit is not drilling into the earth, "turning to the right" or "making pay". Commonly NPT categories are rig repairs, waiting on weather, downhole tool failures, and lost circulation, as well as everyday activities such as pulling dulled bits, running and cementing casing, and wireline logging. NPT is viewed as “flat time” on the time-depth curve. Account for between 20 to 40% of total well construction time, NPT represents a considerable cost and time savings opportunity.