The objective of this research is to determine the integrity of cement filling annulus behind fiberglass casing. The weakly magnetized cements are detected using induction logging. The focus is on numerical simulation of cement containing iron powder magnetization and measurement of magnetic response. We have devised a novel technique for assessing integrity of the weakly magnetic cements behind non-conductive (fiberglass) casing that might be used in the medium-temperature geothermal wells in Saudi Arabia and elsewhere in the Middle East.