In Challenges and Solutions for Accurate Wellbore Placement in the Barents Sea, Xan Mitkus, Stefan Maus, Marc Willerth, Andrew Reetz and others reported on a study carried out for the Petroleum Safety Authority of Norway (PTIL) detailing how to correct MWD surveys at high latitudes for crustal magnetic anomalies and space weather disturbances. The SPE paper is available here, while the complete study is available for download here.
In Validation of Directional Survey Data Against Positional Uncertainty Models, Marc Willerth and Stefan Maus propose novel approaches to identify evaluate MWD survey errors. These methods enable the automation of survey validation and error escalation to efficiently monitor horizontal drilling operationally. The paper is available on OnePetro here.