Enhanced rheological profile and fluid loss control with low sag tendency.
An operator required a cost-effective, high-temperature water-based fluid solution to drill three intervals and maintain stability through wireline logging. Offset data showed a prevalence of barite sag, unsuccessful logs, and severe lost circulation. High-temperature oil-based systems were not considered cost efficient for this project due to the expected lost circulation in limestone formations.
Thermal stability was the major concern as wireline logging was expected to take multiple days. The fluid would be required to remain static in the wellbore at up to 375 degF [191 degC] and needed to be compatible with commercial scavengers.