... of gas in three dimensions helps explain "lazy" neutron curves. In gas zones, the density log is highly affected by varying invasion, where as the neutron has an almost constant gas effect that is relatively independent of invasion as predicted by modeling. neutron measurement neutron...

... ABSTRACT In wireline logging, standoff effects on density, photoelectric factor (Pe), and neutron measurements are reduced by forcing the density pad and neutron assembly against the borehole wall. However, this technique is not practical for logging-while-drilling devices. Consequently...