Location
North Sea, Europe, Offshore
Background
An operator was looking at the possibility of drilling a vertical 17 1/2-in section to TD without using oil-based mud (OBM), which would save the operator approximately USD 1 million in waste costs. The proposed solution was a high-performance water-based mud (WBM) system, and the main KPI was to drill the section and cement the casing without any NPT due to fluid-related issues. The section included a thick shale formation, increasing the risk of not drilling with an OBM. As the operator accepted the use of a high-performance WBM, M-I SWACO recommended the HydraGlyde Optima flexible high-performance water-based drilling fluid system. The main criteria for choosing the system over a standard WBM was based on accretion test results on the well-specific shale showing a reduction from 33% to 18%.
