TX 75083-3836, U.S.A., fax 01-972-952-9435.
AbstractA mechanism for conveying logging tools inside drill pipe has been developed that reduces the risk and cost of acquiring open hole formation evaluation data in high angle wells and bad hole conditions. The measurement string is garaged inside drill pipe where it is protected while running-in, being released into open hole close to final depth. Wireline tools are used for data quality reasons, but the wireline has been eliminated, giving time, well access and well control advantages relative to wireline pipe conveyed logging. Over shallow, long horizontal intervals the time savings are substantial because wireline re-latching is eliminated, and pipe is run-in at tripping speed. The ability to circulate over and around the tools means that logging and hole cleaning trips can be combined to give further time reductions. Cost and data quality advantages have been demonstrated relative to logging-while-drilling in wells where real-time formation evaluation data is not used to guide the drilling process.A 1.4-Km test loop constructed during the development phase proved the tool deployment sequence can be controlled and monitored using mud pressure. It enabled the design to be refined before being run in real well environments, and resulted in the development of novel payload delivery seals -a key component in the system.Using the new method, formation evaluation data has been acquired in horizontal wells that would not have been logged previously for reasons of accessibility and/or cost. Knowledge gained from the interpretation of these data sets has influenced the installation of completions in new wellbores, and guided remedial action in others.