MWD Surveying Enhancement Techniques and Survey Management Workflows Applied at a Barents Sea Field for Accurate Wellbore Positioning

摘要

This paper aims to provide an understanding of the various measurement-while-drilling (MWD) surveying enhancement techniques applied in drilling operations at the Goliat Field located in the Barents Sea to assure accurate wellbore positioning. In high-latitude locations such as the Barents Sea, the elevated, time-dependent variations in the magnetic field create a challenge to the azimuthal measurements provided by the MWD tool. This will induce large uncertainty levels in the MWD surveys compromising the azimuthal errors established within the standard industry error models. To compensate for this effect, crustal magnetic field and time-based magnetic field disturbances were acquired to understand their impact on the MWD surveys and any associated error. This permitted drilling without compromising rig time, and the resultant reduction in lateral uncertainty was approximately 65%.