WSAG
Lundi Log 003
Example below is a wireline triple-combo log suite. Details about logging environment and curves are in the illustration and caption.
Describe log curve behavior and likely causes.
This real example really isn’t a loony log but it’s still Monday. What does get loony are the various “training” models that regularly appear on LinkedIn. Nonetheless, I do still use them frequently for training purposes in log analysis courses, but not so much for their intended purpose but rather as exercises for trainees to determine why they are flawed! We might just have to visit some of these on a future Wrong Way Wednesday posting!
Scroll below for interpretation.
Figure 1. Wireline triple-combo log suite from an undisclosed location. Curve presentation are essentially standard displays, although GR uses a 20–120 api scale rather than more typical 0–150. Neutron porosity is in apparent SS units. Resistivity curves are inverted, vertical resolution matched (2 ft), fixed depth of investigation curves (1, 10 in; 2, 20 in; …; and X, 120 in).
Lundi Log 003 Interpretation
Reservoir with Gas, Oil, and Water Zones
Example of a three-phase reservoir system: upper gas zone, intermediate oil zone and lower wet zone. The gas zone is unusual in that a simple fluid density calculation yields dry gas or depleted gas, either of which are typically not seen above an oil leg. I unfortunately don’t have the full details/particulars here for explaining the unusual gas profile.
