|TDSP™ III is the viscosified sweep stage. TDSP III spacer is used between the surfactant wash spacer and the CBF. This stage is designed to remove any residual materials that are dispersed by the surfactant wash and to provide warning of the returning brine. This allows time for personnel to divert returns once the spacer system has been circulated out of the well.
Like TDSP I, TDSP III should exhibit rheological properties that allow it to maintain its integrity while traveling through the wellbore. This integrity is essential in minimizing the commingling of the TDSP III and the completion fluid. Individual stage volumes are designed with three goals in mind:
- to allow physical separation to protect the brine from mud contamination,
- to provide sufficient contact time for efficient cleaning of the wellbore, and
- to carry residual solids out of the wellbore.