Because the Schlumberger VSP tool was oversized (3.85"+ OD) it would not fit through a standard landing ring (3.81" ID) placed in the landing saver sub. The landing shoulder is required for landing the Kinley crimper/cutter tool should a logging tool become stuck in the hole. To solve this problem, a standard landing ring was opened up to 3.918" ID. The landing shoulder on the Kinley tool is 4.000" and that left ~41 thousandths on a side to land on.

The modified ring was painted and marked both with a paint marker and a wire bound tag to indicate its current internal diameter size. We have stored this modified replaceable seat on the shelf in the Core Tech shop for potential use on future legs, such as Leg 179, when the oversized VSP may again be deployed. This same VSP tool would also not fit through the TAM straddle packer assembly. Without a casing hanger installed in the HRB, there was no way to isolate drill string noise during the VSP experiment.

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