Traditionally, the steering of horizontal wells has been based on logging-while-drilling measurements that rely on the sensors to actually measure the formation's characteristics when drilling through it and then use this information to make the correct steering decision. This approach is a reactive one, however. The implementation of deep and directional electromagnetic measurements that can detect approaching boundaries enables us to implement a proactive steering approach.
Another key element of the new approach is the ability to make geosteering decisions to change the well trajectory in both inclination and azimuth. This is a critical success factor when dealing with a channel sand environment, where the shape of the sand bodies is not well delineated by seismic data.
This challenging work calls for multidisciplinary collaboration and integration of techniques to succeed in maximizing the net-to-gross ratio obtained from drilling horizontal laterals in such environment. Similar collaboration has been facilitated using a workflow that helped the geosteering operation run effectively, even within a large geosteering team from different backgrounds and companies.
In this paper, we look at case studies where the new technique has been implemented. We discuss aspects that lead to the success of this approach and the learning points gathered from the case studies are presented as well.