Challenge

An Operator in Mexico’s Marine Region was drilling an exploration well in order to log and quantify the oil reserves in place. While attempting to drill through a trouble formation below the 9-5/8 in. casing, they experienced severe losses and were forced to plug with cement and plan for a sidetrack.

Sidetracking out of the 9-5/8 in. casing to isolate the trouble zone using conventional casing would mean they would not be able to continue drilling the next section and drill to TD with the planned size. They required a solution that would isolate the formation while providing the required ID to reach TD and run the logs to complete the evaluation.

Solution

Enventure and the Operator worked together to plan the application to sidetrack out of the 9-5/8 in. casing using a whipstock. A 7-5/8 in. High Performance ESET Liner was installed with an additional anchor hanger run at bottom in the open hole to ensure a successful pressure test after expansion. The rotating capability of the ESET liner ensured that the liner would be set at the planned depth. The liner was successfully expanded to cover the 2,560 feet of unstable formation. The post-expanded drift of the expanded liner provided the maximum ID at TD, enabling evaluation of the reserves.

The Operator had previously attempted to cross this formation unsuccessfully. Without the expandable solution the Operator would have made the difficult decision to abandon the well without logging it. The ESET Liner installation saved the investment already made in drilling this well, meeting the Operator’s evaluation objectives.

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