A – B – C – D – E – F – G – H – I – J – K – L – M – N – O – P – R – S – T – U – V – W – X
| NAAQS | National Ambient Air Quality Standards |
| NACE | National Association of Corrosion Engineers |
| NGRC | National Geological Records Centre (United Kingdom) |
| NGDC | National Geoscience Data Centre (United Kingdom) |
| NHDA | National Hydrocarbons Data Archive (United Kingdom) |
| NIMS | National Incident Management System |
| NIPP | National Infrastructure Protection Plan |
| NIOSH | National Institute for Occupational Safety, a US agency working to prevent work-related injury and illness |
| NOIA | National Ocean Industries Association |
| NOAA | National Oceanic and Atmospheric Administration |
| 40 CFR Part 300 | National Oil and Hazardous Substances Pollution Contingency Plan |
| NOC | National Oil Company |
| NOV | National Oilwell Varco |
| NPDES | National Pollutant Discharge Elimination System, authorized by the US Clean Water Act |
| NRDA | National resource damage assessment |
| NRC | National Response Corporation |
| NRT | National response team |
| NTP | National Toxicology Program |
| NWR | National wildlife refuge |
| NGR | Natural Gamma Ray |
| NG | Natural Gas |
| NGH | Natural gas hydrate (methane clathrate, or fire ice) |
| NGL | Natural Gas Liquids |
| NGPL | Natural gas pipeline |
| NORM | Naturally occurring radioactive material |
| 33 CFR 142 | Navigation and Navigable Waters, Workplace Safety and Health (US Regulation) |
| NAVIG | Navigational Log |
| NBR | Near-bit reamer |
| NTU | Nephelometric Turbidity Unit |
| NHPV | Net Hydrocarbon Pore Volume |
| NPSH | Net Positive Suction Head |
| NPV | Net present value |
| NRI | Net Revenue Interest |
| NEUT | Neutron Log |
| NFW | New Field Wildcat, Lahee classification |
| NPW | New Pool Wildcat, Lahee classification |
| NYMEX | New York Mercantile Exchange |
| N | Newton |
| NGS | NGS Log |
| NGSS | NGS Spectro Log |
| NGTLD | NGT LDT QL Log |
| NGT | NGT Log |
| NGLQT | NGT QL Log |
| NGTR | NGT Ratio Log |
| NCDMB | Nigerian Content Development and Monitoring Board |
| ND | Nipple Down |
| NOX | Nitrogen oxides |
| NFG | ‘No Fucking Good’ used for marking damaged equipment, not to be confused with NG being natural gas |
| NFI | No Further Investment |
| NOISL | Noise Log |
| NB | Nominal Bore |
| NPS | Nominal Pipe Size (sometimes NS) |
| NASA | Non Active Side Arm (term used in the North Sea for kill wing valve on a Xmas tree) |
| NAPF | Non Aqueous Phase Fluid |
| NDE | Non Destructive Examination |
| NMDC | Non Magnetic Drill Collar |
| NP | Non Producing well (as opposed to P |
| NRV | Non Return Valve |
| NCR | Nonconformance report |
| NDT | Nondestructive testing |
| NGO | Non-governmental organization |
| NOW | Non-hazardous oilfield waste |
| NMHC | Non-Methane Hydrocarbons |
| NMVOC | Non-Methane Volatile Organic Compounds |
| NPT | Nonproductive time |
| NTHF | Non-Toxic High Flash |
| NMO | Normal moveout offset (arrival time offset) |
| NORSOK | Norsk Sokkels Konkurranseposisjon, standards for the Norwegian petroleum industry |
| PN | North Padre Island Area Gulf of Mexico leasing area |
| NS | North Sea; can also refer to the North Slope Borough, Alaska, the North Slope, which includes Prudhoe Bay Oil Field (the largest US oil field), Kuparuk Oil Field, Milne Point, Lisburne, and Point McIntyre among others. |
| N/S | North/south |
| NNS | Northern North Sea |
| NPD | Norwegian Petroleum Directorate |
| NIMBY | Not in my backyard |
| NTE | Not to exceed |
| NOI | Notice of intent |
| NPR | Notice of proposed rulemaking |
| NTL | Notice to Lessees and Operators |
| NMR | Nuclear magnetic resonance |
| NMR | Nuclear Magnetic Resonance Log |