Performance of a New 2.35-in. Wireline or Memory Quad Combo for Through-Bit or Small-Hole Logging

Abstract

A new UltraSlim™ quad combo has been developed and deployed with log quality very comparable to that of larger tools. The suite of logging tools is backed up by a full complement of swivels, knuckles, flex joints, springs, weights, cable head, and latches adaptable to the situation. The string can be conveyed by wireline using conventional power and telemetry, either through-and-below drill pipe or in a conventional open-hole log run. The combo can also be run in the hole by slickline inside drill pipe, then pumped out and latched beneath the bit, using its downhole battery and memory. The tool string has been logged successfully in more than twenty commercial operations in operator wells and two of Halliburton's test wells. The combo and its peripheral equipment have performed without incident. Some of these log runs were made back-to-back with standard-sized logging equipment for the purposes of certifying that the log quality is comparable. The string features an array induction log with number of coils and spacings identical to its larger siblings, array sonic with dual transmitters, deployable-pad density with PE and caliper, dual-spaced neutron, gamma ray, and borehole environmental measurements. This paper describes the UltraSlim logging system and provides details of its reliability, repeatability, accuracy, and petrophysical performance in comparison to standard-size logging tools, by means of visual and statistical log analysis.