Multi-Sensor Through-Casing Density and Saturation Measurement Concepts Witha Pulsed Neutron Source: A Modeling Assessment

摘要

The paper discusses an assessment, using Monte Carlornmodeling techniques, of the advantages we could derivernand challenges we would face in utlizing multiplernsensors with a pulsed neutron (PN) source for cased-holernlogging to obtain petrophysical parameters. Current PNrndevices are primarily based on two detectors, withrnsource-detector spacing often similar among the variousrnvendors. We consider four sensors to investigate threernmeasurement types, 1) a pseudo-density through casingrnconcept that shows the potential to distinguish betweenrngas and tight zones, 2) computing oil saturation fromrnCarbon/Oxygen logs with oil present in the borehole,rnand 3) estimation of Sigma and hence water and steamrnsaturation from PNC logs. We illustrate the advantagesrnof using modeling to study measurement conceptsrnindependent of specific tools. We identify areas ofrnfurther research in basic measurement concepts usingrnpulsed sources and in related radiation transport theory.