Abstract
Summary The use of measurement while drilling (MWD) resistivity tools in boreholes 8½ in. and greater in diameter has evolved over the past 10 years from a little-used, qualitative service to a routinely used quantitative service in directional, horizontal, and extended-reach wells. Today's applications include reconnaissance logging, geo-steering, pore pressure evaluation, wireline replacement, and enhanced formation evaluation. Over the last several years, there has been an increasing trend worldwide toward drilling smaller boreholes to optimize the costs of tubulars and gain greater drilling efficiencies. Until recently, there have been no MWD resistivity tools available for logging 6-in. diameter boreholes. A new multiple-depth-of-investigation MWD resistivity sensor housed in a nominal 4$34-in. diameter drill collar has been developed for use in slimhole drilling operations. This new MWD resistivity sensor provides eight different depths of investigation in any mud type and allows for derivation of the flushed zone resistivity, true resistivity, and the diameter of invasion across a wide range of formation resistivities. The tool is designed for boreholes larger than 5⅞ in. in diameter and can be used in medium-radius drilling applications. Extensive operations in the North Sea, Gulf of Mexico, south Texas, Middle East, Alaska, and Australia have demonstrated a variety of applications. Slimhole MWD resistivity has been shown to have use in geosteering horizontal wells to maintain and optimize wellbore placement. Additionally, it allows determination of true formation resistivity and diameter of invasion for formations with invasion effects and provides for application of advanced modeling techniques to enhance formation evaluation and log interpretation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.