Abstract
It is very important to understand the mechanisms involved during the tripping job and to know about the factors that come into play during and after the tripping operation. There are a number of downhole parameters involved that can interrupt the normal tripping activity and can lead to serious well control situations, such as blow out.
According to estimates in Louisiana, Texas during 1960- 1996, a total of 430 blowouts occurred during drilling, of which pulling out of the hole (swabbing) took the lead with 158 blowouts.
In addition to surge and swab that might come into play, one of the unforeseen problems in tripping job is tight hole that in worse case can lead to stuck pipe and brings about major Non-Productive Time (NPT) of the operation. The causes of tight holes include: Formation related problems (tectonics, etc), borehole trajectory, insufficient inhibition, improper mud weight, lack of lubricity and inadequate hole cleaning.
There are several problems that arise during tripping in/out in the wellbore but emphasis has been placed on tight hole in this study because of high financial impact the drilling industry encounters and downtime it poses during drilling operations.
In this study this challenge that is associated with tripping operations (tight hole) will be implemented in a 3D Virtual Drilling Simulator for a field case in the North Sea and interesting results have been presented. In addition to invaluable results inferred, the 3D Virtual Drilling Simulator can be used to train a complete drilling crew for a specific operation (i.e. RIH & POOH and related challenges).
