Precision Enhancement in North-South Directional Drilling Through Definitive Dynamic Surveys

The conventional approach of using continuous direction and inclination while drilling the wellbore was developed and implemented in the late 1970s and became widely adopted in the drilling industry in the early 2000s. This revolutionary method helped the operators to step up in well delivery from drilling only vertical wells to reaching reservoir with application of deviated wells. It became a landmark in directional drilling history, as continuous data was used to steer the well proactively. This allows directional drilling specialists to determine the exact position of the wellbore at any given moment and take faster decisions for trajectory corrections during drilling. The technology has demonstrated good reliability and is now an industry standard. However, this conventional method, which relies on the projection of rotational components and static surveys as references, has limitations when determining the precise direction of the wellbore. Drilling wellbores in the magnetic North-South direction pose a significant technical challenge for conventional Measurement While Drilling (MWD) tools, which use standard Direction and Inclination (D&I) surveying packages to acquire accurate continuous Azimuth data. These tools are relying on Earth's magnetic field to determine orientation. And in direction close to the magnetic poles MWD tool will have reduced capability to resolve direction and provide reliable continuous magnetic Azimuth measurement. Additionally, the magnetic field is prone to interference, further reducing the precision of conventional D&I packages. Drilling equipment and any nearby metallic components exacerbate these challenges, complicating direction determination and computation in such a complex magnetic field environment. Another challenge is cross axial interference, which can affect static survey and lead to inaccurate reference for MWD tool to compute continuous Azimuth.