This study details factors that may help to shed light on challenges and opportunities related to possible reduction of risk of shallow well control incidents.
The number of well control incidents on the Norwegian Continental Shelf, NCS, has not shown a clear downward trend in recent years, ref. published incident statistics in recent years' annual RNNP main reports. The causal relationship to the well control incidents on the Norwegian shelf was investigated through a quantitative in-depth study of well control incidents in 2022, published in the RNNP Main Report 2023, and as a stand-alone report.
A number of well control incidents on the NCS occur during the drilling of boreholes through the uppermost formations under the seabed. Such drilling operations are often referred to as drilling of "pilot holes" or "top-hole" sections. These events are caused by shallow gas deposits or shallow water currents that can occur in formations. For some years, such incidents account for a significant proportion of all well control incidents on the NCS.
This study was therefore initiated by Havtil in 2024 to try to identify guidelines, best practice methodology etc. that may contribute to enabling of reduction of risk and uncertainty in order to avoid some of these events. Part of this ambition was to be able to contribute to identifying good methods for communicating the risk of shallow well control incidents, through the processes of data acquisition, data qualification, well planning and in the execution phases of drilling such shallow formations.
Attached you will find the report from the study.