Optimized Horizontal Well Placement in the Otter Field, North Sea using New Formation Imaging While Drilling Technology

摘要

This paper demonstrates how new Logging While Drilling(LWD) and Measurement While Drilling (MWD) tools wereused to optimise placement of 3 sub-horizontal wells in afaulted, sand-shale oil bearing Brent Group reservoir known asthe Otter Field, Northern North Sea, United Kingdom. As thetarget reservoir layer is only 8m thick and sub-seismic faultingand subtle changes in dip occur in the field, geosteering of thewell paths was anticipated prior to commencing drilling. Toaid with geological steering of the wells a new LWD tool wasrun: the azimuthal GR-resistivity device and this providedhigh-resolution borehole images of formation geology (eg.formation layering and dip, fault location and orientation).Using state-of-the-art mud-pulse MWD telemetry and theworld-wide web, the images and other LWD data (eg.porosity) were made available, real-time, to both the onshoreand offshore drilling team. Detailed geological cross sectionsconstructed in real-time from the image logs aided steering thewells to the optimum geological locations. One of the threeproduction wells [well 210/15a-T2 (P1)] is used todemonstrate how the imaging while drilling, viewed real-timevia the web, was applied. This case study highlights thebenefits the technology brought to the drilling operation andfield development in terms of efficiency improvements ingeological analysis and well steering decision making andmaximized oil production through optimum well placement.