Optimum Use of Seismic Data to Reduce Drilling Risk and Improve Well Placement

The earth model obtained from seismic data is the primary input to well planning. To help place the well in the right “geological” target and to avoid drilling hazards, the earth model required for drilling often needs to be very accurate at the well location. The required accuracy and resolution for drilling purposes is typically higher than what is required by other uses of seismic data in various phases of E&P. Consequently, a best possible predrill model in a small volume around the well location needs to be built before drilling. Furthermore, while the well is being drilled, new information is obtained such as logs, vertical seismic profiling (VSP), mud weight, mud logging, and others that were not available before. These measurements are taken at the new well location and can be used to update the predrill model for a more accurate model of the earth ahead of the drill bit for better well placement and drilling hazard management. The lack of adequate technologies and measurements, and turnaround time limitations, have made this type of optimum utilization of seismic and well data (predrill and while drilling) impractical until now. With recent developments in model building, new rapid and accurate imaging technologies, and availability of new well measurements, this is now becoming a reality. In this paper, we review this process, describe the technologies that make it possible, and present a field study