Dealing with uncertainty on horizontal well trajectory when targeting new infill drilling: The Brage Field case study

Uncertainty quantification has become an increasingly important request in the decision-making process for targeting infill drilling. Serious weaknesses in current reservoir models can be directly attributed to the lack of proper uncertainty handling. In a mature field as Brage, where there are many long horizontal wells, uncertainty in well markers and well paths have a tremendous impact on the structural uncertainty ( + /−10m). These variations on their own can either create or kill infill drilling targets. A stochastic way of dealing with uncertainty on horizontal well trajectories has been derived for a consistent updating of velocity and depth models.