This paper will examine the management issues, safety concerns of planning and executing a high end underbalanced drilling project. The discussion will include general safety, training, equipment, and conclusions.
Underbalanced drilling is inherently more dangerous than conventional drilling but the danger is mitigated by proficient project management, specifically, planning, training and the operational procedures followed during execution. Statistically, underbalanced drilling is still a very small percentage of worldwide drilling operations. This trend is changing as this disruptive technology is becoming more and more accepted throughout the industry. Our biggest challenge in the future will be to ensure that the past history of no major incidents or accidents attributed to Underbalanced drilling continues.
The planning that goes into an underbalanced drilling operation is more extensive than the planning of a conventionally drilled well. Some of the tools used in the planning phase of underbalanced operations include hazard identification (HAZID), hazard and operability (HAZOP), detailed operational procedures, and drawings such as equipment layout drawings (ELD), process flow diagram (PFD), valve numbering diagram (VND) and a hazardous area drawing (HAD). These processes contribute considerably to reducing the time and cost of engineering the underbalanced drilling program.