ABSTRACT: Quantitative Open-Hole Logging with Very Small Diameter Wireline Tools
Small-diameter logging tools -- or true Slimeline(tm) tools -- commonly are regarded by many workers as merely qualitative "poor
relations" to full-size tools. A suite of logging tools having diameters of approximately 2 in was developed. These tools give good calibrated results in hole sizes of 8 in. or more.
The suit of measurement types currently available includes compensated density, compensated neutron, multiple receiver sonic, dual laterolog, microresistivity, dipmeter (with real-time dip computation), and check-shot surveys. Many other measurements specific to mineral applications also can be made.
The oil-field measurements are based on sound physical principles, and the calibration and response function characterization of these smaller tools commonly meets more stringent requirements than do their "big brothers." Some of these techniques illustrate the linkage and rigor of the resulting algorithms.
When employed in Slimline holes, these measurements are shown to equal the quality of full-size tool measurements, but with the advantage of a much lower cost for drilling and logging.
Modern PC-based surface systems complement the down-hole equipment, producing both hard copy and magnetic output that is indistinguishable from the output of conventional systems. The output quality is coupled with high portability and a very light weight, making the system easy to mount in lightweight go-anywhere vehicles or in a small helicopter-borne skids.
Examples of logs from a range of environments illustrate the quality and compatibility of the data and address some fundamental questions about techniques regarded as standard for many years.
AAPG Search and Discovery Article #90991©1993 AAPG Mid-Continent Section Meeting, Amarillo, Texas, October 10-12, 1993.