Advanced, dual sensor technology helps accurately measure formation porosity
The CNL is primarily used to determine formation porosity in open hole. It is compensated for various environmental conditions and can also be used to determine porosity through casing. Other applications include lithology identification, clay analysis, and gas detection.
The neutron source emits fast neutrons. These neutrons bombard the formation and are thermalized (slowed) mainly by collision with hydrogen nuclei in the rock pores (ie water / hydrocarbon). Some of the thermalized neutrons return to the tool where they are counted by two He3 detectors spaced at different distances from the source. The dual sensors enable compensation for borehole conditions.
The CNL is normally run with a bowspring decentralizer to ensure that the tool is pushed against the borehole wall. This minimizes the effects of the borehole fluid, and enables the provision of consistently high quality data.
The CNL tool runs on the Ultrawire toolbus.