PERFORMAX Delivers Environmentally Neutral Operations in Offshore Nigeria

Operator seeks a better alternative mud system

Environmental requirements have become a focal point around the Nigerian coast. Recently, a major operator expressed a long-term desire to eliminate the use of any invert emulsion system in the area, including synthetic, oil-based mud (SOBM) systems.

Since wellbore stability in this region is a critical issue due to the highly reactive and troublesome Qua Ibo shale, waterbased mud (WBM) fluids have not been traditionally used by Nigerian operators due to their poor performance history. Baker Hughes provided the PERFORMAX™ water-based fluid system for this project because it can perform at levels near those of SOBM, while offering enhanced environmental compliance.

The PERFORMAX high-performance fluid system was used while drilling the 17½-in. section, with no indications of wellbore instability in the highly reactive formation despite 20 days of openhole time. Depleted sands were encountered at 6,950 ft, and with hydrostatic overbalances reaching 1,750 psi, the PERFORMAX system was able to successfully isolate these sands with no differential sticking.

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