The biggest challenge of well placement is uncertainty. This uncertainty is a culmination of technical limitations, measurement quality, and understanding of the subsurface, which sometimes stems from low-resolution seismic data. Within the reservoir, proper well placement requires an understanding of the complexity of the geology and petrophysics. Without the right measurements, operators have to make a lot of assumptions. Schlumberger has a full fleet of measurement- and logging-while-drilling services as well as interpretation services using the Petrel E&P software platform that fill these gaps to reduce uncertainty.