The result shows that the main reasons are high bottomholetemperature, corrosion of drilling tool during storage and drilling process, high value of formation drillability, and multi-fault.
In log interpretation, the bottomholetemperature (BHT) is taken as the maximum recorded temperature during a logging run, or preferably the last of series of runs during the same operation.
The term refers particularly to a mud sample that has experienced stagnant conditions at the bottom of the hole, including the temperature, pressure and other conditions at that depth.