Our value rated atmospheric RAD anomalies are indicators of hydrocarbons at some unspecified depth.  These anomalies may be associated with the targeted geologic zones or they may be sourced from another formation that has thus far been overlooked or ignored completely.  It is the interpreter’s responsibility to try and determine a logical source for the RAD anomaly. (see Fig. 1) Most 3-D surveys are shot to obtain data over a known target, a producing formation, an exploration discovery or a specific exploration objective.  Of course, the seismic data covers a much thicker geologic section than just the targeted zone(s).  How many times have we logged unexpected pay zone(s) while drilling to the main objectives? One method that is found to work for some entails the importation of the RAD data, as grids, into the seismic 3-D interpretation package.  One geophysicist’s method is to scale the data to something like 0-100 then convert it to a pseudo horizon.  Display the pseudo horizon on your seismic section, it will show up at zero time.  So if your target zone is at 2 seconds add 2000 to your horizon and it will now show up at 2 seconds on the seismic line.  The RAD  anomaly will then be shown adjacent to your seismic objective horizon; you may have to flip the sign so that the higher RAD values of the pseudo horizon will be up around 1.9 seconds and white data (no anomaly) will be at 2.0 seconds. (see Fig. 2) If the anomaly corresponds to the objective then you have confirmation that your interpretation may be valid.  If however, there is no logical comparison between the seismic and the anomaly then shift the RAD horizon up or down the seismic section until something lines up.  Perhaps there is a fault that matches the edge of the RAD anomaly or a seismic doublet that could represent a hydrocarbon charged channel sand that matches the anomaly.  Compare waveform changes or amplitude anomalies, any subtle seismic attribute that may be significant to the RAD pseudo horizon; then map it. You should get the point by now.  Use the RAD data to peruse the entire seismic volume for unforeseen potential hydrocarbon zones You may be surprised as to where your next well should be drilled. 3D Seismic Reeves Technology Corporation 498 Curtis Road  -  Burleson, TX 76028 817-447-8056 samreeves@reevestech.com click thumbnail to enlarge Fig. 1* Fig. 2 (Interpreted) click thumbnail to enlarge *The image in Fig. 1 was produced using a different color scale than the one currently used for RAD Maps. *The image in Fig. 1 was produced using a different color scale than the one currently used for RAD Maps. Fig. 2 (Raw Seismic) click thumbnail to enlarge