NGI Logged over 2400m section at 67° deviation in New Zealand

An operator in New Zealand drilled a challenging sidetrack well featuring a 2400m, 67deg tangent section. Equipment failures in the BHA resulted in a corkscrew hole in the lower half of the well. It was critical that the operator logged the NGI in this well as the field contains complex geological structures. Petromac provided a custom-made Tool Taxi which centered the NGI within 0.3in of the center of the wellbore. In this configuration the NGI can be run without standoffs, which induce drag and cause stick slip motion. Micro-resistivity imaging tools such as OBMI, FMI and NGI are negatively affected by stick slip motion caused by overpulls. Petromac Tool Taxis help to smooth the tool motion, and the result is clear, crisp imaging logs. NGI centered with Tool Taxis in challenging well conditions Fig.1. Logging with Tool Taxis produced an excellent log, with no image rotation or stick slip, despite the poor hole conditions.