Monitor Well Completion Evaluation With Geophysical Density Logging

The competency of monitor well completions with regard to grout<br>continuity and the presence of the bentonite seal and sand pack can be<br>uniquely evaluated with geophysical density logging. This method relies on<br>density contrasts among various completion conditions. The presence or lack<br>of particular completion materials results In differences measurable with<br>geophysical density probes.<br>Empirical measurements made in the laboratory with density probes<br>provide information on depths of investigation and probe response to specific<br>completion conditions. These measurements support interpretations made for<br>two geophysical log examples presented herein. The examples indicate<br>discontinuous grout Intermittent with alluvium and air voids.<br>The economics of the density evaluation method are advantageous,<br>particularly with respect to the implications of a poorly constructed monitor<br>well, which include possible contaminant cross-flow and misspent monitoring<br>expenses.