A Proper Use of the Adjacent Land‐Based Observatory Magnetic Field Data to Account for the Geomagnetic Disturbances During Offshore Directional Drilling

Directional drilling in the oil fields relies particularly on “on-fly” measurements of natural magnetic field (measurements while drilling; MWD); MWD are eventually used to construct well path. These superposition signals from internal, core and crustal, external, ionospheric magnetospheric sources noise elements borehole assembly. The internal mostly constant time accounted for through Earth's models. external origin give rise diurnal irregular spatio-temporal variations observable MWD. One common ways mitigate effects these is correct readings data an adjacent land-based observatory/site. This method assumes that similar those at seabed site. In this paper, we show sea level horizontal differ significantly, reaching up 30% values many oceanic regions. We made inference global forward modeling using realistic models conducting Earth time-varying sources. To perform such modeling, elaborated a numerical approach efficiently calculate evolution field. Finally, propose validate formalism allowing researchers obtain trustworthy site exploiting results, thus without needing additional