MWD tools measure azimuth with respect to the Earth’s magnetic field. This field is a superposition of the global and crustal fields. For accurate wellbore positioning it is critical to have an appropriate geomagnetic model. This model is a representation of spherical harmonic expansions of a magnetic potential.
The enhanced geomagnetic model uses a spherical harmonic representation to degree and order 790. That ensures reliable modeling of the Earth’s global and crustal fields and accurate downhole declination, total field, and dip values.
We integrated the enhanced geomagnetic model into the automation workflow of MWD STD platform. That automates calculation routine, allows to avoid human related errors, and provides geomagnetic reference along trajectory the better system reliability and accuracy.
