Casing setting depths found in Drilling Programmes fall into two categories:
1. Those where the casing is set at a specific marker (ie., formation above reservoir).
2. Those where the casing is set at a convenient point in the total well path.
The casing setting depths in 1. are absolute and the hole shall be drilled to the depth indicated and casing set as specified in the Drilling Programme.
The casing setting depths in 2. are not absolute and it may be possible to set casing where the bit dulls or poor progress is being made. In these cases, the Operations Engineer/Head of Drilling Operations shall be contacted and a decision can then be taken considering the following possibilities:
- log and drill to casing depth with wiper trip.
- log and run casing.
- round trip to drill to casing depth prior to logging.
It is possible in the first two cases that a round trip could be avoided saving rig time and well cost.