Drilling problems
It is almost certain that problems will occur while drilling a well, even in very carefully planned wells. For example, in areas in which similar drilling practices are used, hole problems may have been reported where no such problems existed previously because formations are nonhomogeneous. Therefore, two wells near each other may have totally different geological conditions.
Types of drilling problems
In well planning, the key to achieving objectives successfully is to design drilling programs on the basis of anticipation of potential hole problems rather than on caution and containment. Drilling problems can be very costly. The most prevalent drilling problems include:
- Pipe sticking
- Loss of circulation
- Hole deviation
- Pipe failures
- Borehole instability
- Mud contamination
- Formation damage
- Hole cleaning
- H2S-bearing zones
- Shallow gas zones
- Equipment and personnel-related problems
Understanding and anticipating drilling problems, understanding their causes, and planning solutions are necessary for overall-well-cost control and for successfully reaching the target zone.