Resistivity modelling has several uses. It tells the petrophysicist and Geolog user the effect on the induction log of nearby conductive shales and the minimum thickness of reservoir intervals where the induction log can be trusted. It provides a squared Rt curve for water saturation calculation.

Operating Instructions:

• The interval of interest should be the logged interval across the reservoir section +/- 50 feet.
• Create a zone set - called BED.TOPS using loglan tp_derivative to pick first pass bed boundaries by differentiating the induction log deep curve (Rt).
• Copy Rt to BED.TOPS to creates the first pass zonal average resistivities Make sure it is REAL rather than ALPHA
• Set your geolog screen by tiling display - layout, loglan, text and module
• Run RTMOD, as required, using F7
• Make sure sampling is DEPTH.RTMOD
• Adjust bed boundaries and bed resistivity to get best match.