Image Logs Worth Hundred Applications: Industry’s First Innovative High-Resolution Dual-Imager Logging-while-Drilling Technology Overcomes Barriers of Oil-base-Mud

Summary An innovative LWD dual-physics imager has been recently deployed, providing much-needed high resolution measurements for the ever-growing applications through various stages of an oilfield; thereby finally providing borehole images in OBM while drilling worthy of hundred applications with real-time capabilities. Full-bore images can be acquired simultaneously; apparent resistivity images from electromagnetic measurements, and acoustic amplitude & transit time images from ultrasonic measurements. The resistivity images provide rich information related to sedimentation style, highlighting the sedimentary structures, textural variation and diaenetic imprints; while the ultrasonic images are more sensitive to fractures and drilling induced features, such as induced fractures and break-out. This innovation LWD tool combines the complementing nature of the high-resolution ultrasonic and electromagnetic image technology without introducing complexity to the drilling bottom-hole assembly in a 15-ft sub. However, many sub-seismic structures (fractures/ faults) are found to be better imaged on apparent resistivity images quite often due to the contrasting features across them. And, a few times even the ultrasonic images could show thin-beds if enough contrast is seen due to cementation along some beds. Therefore, the need of the dual imager is established to image different features for comprehensive geological interpretation, wellbore stability related features and further petrophysical applications