SeaFloor EngineeringThe Mapping-While-Drilling EvolutionBy Claudio Paschoa ogging-while-drilling (LWD) technologies have investigation, enabling operators to optimize landing, maxi-evolved signi? cantly in the past decade. Today they mize reservoir exposure, and re? ne ? eld development plans. integrate sophisticated algorithms that take advan- By integrating real-time reservoir maps with seismic surveys, Ltage of the ever-increasing technical complexity interpretation of reservoir structure and geometry can be re-combining mechanical, electrical and software systems that ? ned, revolutionizing ? eld development strategy.are implemented downhole. These achievements help the us- What different ? elds of research were involved in developing ers gain a better understanding of the reservoir while bring the GeoSphere reservoir mapping-while-drilling service?drilling into a new area of ef? ciency and cost savings. Marine Mechanical, electrical, and software engineering that deliver Technology Reporter’s Correspondent in Brazil spoke to Jean deep directional measurements are at the core of the hardware Seydoux, Program Manager for Advanced Reservoir Mapping development. Technologies for Drilling and Measurement at Schlumberger, From these measurements, a resistivity map of the reservoir about their GeoSphere Mapping-While-Drilling Service. is inverted using a novel stochastic process that allows the drilling team and geoscientists (such as petrophysicists, ge-ologists and reservoir engineers) to ? rst understand and then What were the breakthroughs in this technol-steer within a geological structure tens of meters away from ogy’s development along the last ? ve years? In 2014, Schlumberger introduced the GeoSphere technolo- the borehole—all in real time. gy, the ? rst-ever reservoir mapping-while-drilling service that By revealing details of structural dips and ? uid boundaries enables customers to map their reservoirs using unprecedent- in geological structures, the real-time mapping data provides ed depth of investigation measurements around the wellbore operators with information critical to avoiding undesired exits coupled with a novel mathematical inversion methodology. into nonproductive layers. Using deep, directional electromagnetic measurements, the How does mapping-while-drilling system work?GeoSphere service reveals subsurface-bedding and ? uid-contact details more than 100 ft [30 m] from the wellbore. The GeoSphere mapping-while-drilling service follows a This reservoir-scale view provides an unprecedented depth of standard pre-job modeling, real-time execution and post-job September 201740 MTRMTR #7 (34-49).indd 40 MTR #7 (34-49).indd 40 8/23/2017 4:18:46 PM8/23/2017 4:18:46 PM