A combination of logs or a computation procedure for calculating the depth of invasion and the resistivity of both invaded and uncontaminated zones, based on a dual induction-laterolog and a proximity log or microlaterolog.

For Baker-Atlas: a “Grand-SLAM” is a service combination comprising Density, Neutron, Resistivity and Sonic measurements (as well as Gamma-Ray), where “Resistivity” can mean a measurement in resistive or conductive environment to define the resistivity of the formation. It is equivalent to a Mini-SLAM, with the added Sonic service.