Discovery and Integration by Increasing Resolution, Obtaining Borehole Images while Drilling: First Multivendor LWD Success Story from Gulf of Mexico

Abstract

Abstract As if drilling targets in deep water environments were not challenging enough, key subsurface complexities are being unveiled as we improve measurements resolution that provide insights into reservoir characteristics previously invisible with previous technologies such as conventional logs. With this, new wells delivery risk profiles and economics are challenged with geoscientists demanding high-resolution well-logs of different measurements while drilling commences that historically have been deployed on wireline. Often, the drilling vendors are identified early for logistically complex operations; and post-drilling wireline logging is not the most favorable deployment system decision due to salt tectonics inducing operational challenges, specifically in the case of the Thunderhorse reservoir where different degrees of depletion add a considerable differential sticking operational risks. Additionally, not all the high-resolution logging technologies are available while drilling, and such gaps are wider in wells drilled with non-conductive mud as limitations in technology and tool sizes prevail. In the specific case of deep water turbidites depositional environments, the need for high resolution images was historically fulfilled running a post-drilling wireline run, until a multi-vendor solution to acquire the data while drilling, provided high quality real-time borehole images in support of operations and reservoir description objectives. This multivendor integration technology approach was planned, tested, and successfully deployed in three new subsalt deep-water wells where a LWD dual imager with real-time image transmission capability was used in a different LWD provider of the main drilling bottom-hole-assembly (BHA). This novel technique required rigging up two independent telemetry systems to power up and transmit simultaneously quad-combo and pressures data from vendor-A and real-time borehole-images from vendor-B. This was first of its kind attempt to run two sophisticated logging technologies from different service providers needed to achieve key logging objectives while drilling. Many rounds of technical discussion with operations and technology teams made this effort a success with several lessons learned. After operational considerations were factored in, focus shifted to seamless transmission of data and its real-time delivery for operations continuity. With limited telemetry, the LWD dual-imager’s data transmission capability could provide high-quality features-picking on real-time images to advise the simultaneous formation pressures operations and assist selecting the most suitable depths for probe-positioning, staying away from faults, fractures and cemented intervals. High quality data was then acquired while drilling, meeting the logging objectives while drilling, minimizing the need of operationally challenging and expensive subsequent wireline run. This, first of its kind multi-vendor success story provides insights into addressing a technical challenge as one team and overcoming the technology portfolio gap with integrated innovative solutions for successful operations and data acquisition.