Blowout and Oil Spill Modelling
Drilling
When planning an offshore well (or any well, for that manner) the well construction process is focused on safely executing the drilling and completion of the well. However, in the event of a well control incident, an estimation of the worst case discharge from an offshore well is required. In the United States this is mandated by the document BOEM NTL No. 2015-01, which supersedes the previous BOEM NTL No. 2010-N06. According to NTL-No-2015-N01, the operator has to submit a plan which describes the scenario of the worst case blowout potential during the well construction. This includes the flowrate from the drilled zones, the potential for bridging off, the availability of a rig to drill a relief well and the time it will take to intersect the subject well with the relief well. According to the SPE guidance for complying with BOEM NTL No. 2010-N06 (from September, 2010) the procedure (in brief) is as follow; To determine the Worst Case discharge scenario, all potential hydrocarbon-bearing formations in each hole section will have an absolute open flow calculated, and the hole section with the highest AOF will be used. The time to drill a relief well for this hole section is to be calculated. A production profile (including commingling and decline) is created, and the flow rate over the relief well time is then used to determine the worst case oil spill volume. The time to drill a relief well includes the contracting, mobilization, and potential sidetracking to intersect the original wellbore.
Blowout and Oil Spill Modelling
Drilling
When planning an offshore well (or any well, for that manner) the well construction process is focused on safely executing the drilling and completion of the well. However, in the event of a well control incident, an estimation of the worst case discharge from an offshore well is required. In the United States this is mandated by the document BOEM NTL No. 2015-01, which supersedes the previous BOEM NTL No. 2010-N06. According to NTL-No-2015-N01, the operator has to submit a plan which describes the scenario of the worst case blowout potential during the well construction. This includes the flowrate from the drilled zones, the potential for bridging off, the availability of a rig to drill a relief well and the time it will take to intersect the subject well with the relief well. According to the SPE guidance for complying with BOEM NTL No. 2010-N06 (from September, 2010) the procedure (in brief) is as follow; To determine the Worst Case discharge scenario, all potential hydrocarbon-bearing formations in each hole section will have an absolute open flow calculated, and the hole section with the highest AOF will be used. The time to drill a relief well for this hole section is to be calculated. A production profile (including commingling and decline) is created, and the flow rate over the relief well time is then used to determine the worst case oil spill volume. The time to drill a relief well includes the contracting, mobilization, and potential sidetracking to intersect the original wellbore.