O
- O&G – Oil and Gas
- O&M – Operations and Maintenance
- OBCS – Ocean Bottom Cable System
- OBDTL – OBDT Log
- OBEVA – OBDT Evaluation Report
- OBM – Oil-Based Mud
- OCIMF – Oil Companies International Marine Forum
- OCL – Quality Control Log
- OCTG – Oil Country Tubular Goods (oil well casing, tubing, and drill pipe)
- OD – Outer Diameter (of a tubular component such as casing)
- ODT – Oil Down To
- OFST – Offset Vertical Seismic Profile
- OEM – Original Equipment Manufacturer
- OH – Openhole Log
- OHC – Open Hole Completion
- OIM – Offshore Installation Manager
- OMRL – Oriented Micro-Resistivity Log
- ONAN – Oil Natural Air Natural cooled transformer
- OOE – Offshore Operation Engineer (senior technical authority on an offshore oil platform)
- OOIP – Original Oil In Place
- OOT – Out of Tolerance
- OPEC – Organization of Petroleum Exporting Countries
- OPL – Operations Log
- OPRES – Overpressure Log
- OPS – Operations Report
- ORICO – Oriented Core Data Report
- OS&D - Over, Short & Damage (Report)
- OT – A Well On Test
- OTDR – Optical Time Domain Reflectometry
- OTIP – Operational Testing Implementation Plan
- OTL – Operations Team Leader
- OWC – Oil Water Contact
- OT – Off Tree
- OUT – Outpost, Lahee classification
- OUT – Oil Up To
- OVCH – Oversize Charts
- OVID – Offshore Vessel Inspection Database
- OWC – Oil-Water Contact
Read more about this topic: List Of Oil Field Acronyms