Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Lockout/tagout
Definition(s)
Lockout/Tagout
A safety procedure used to ensure that piping is properly isolated and cannot be energized or put back in service prior to the completion of inspection, maintenance, or servicing work.
Source: API 570, Piping Inspection Code: In-service Inspection, Rating, Repair, and Alteration of Piping Systems, Fourth Edition, February 2016, with Addendum May 2017. Global StandardsLockout/Tagout
Use of either a lockout or tagout procedure conforming to OSHA 1910.147. API RP 2201, Safe Hot Tapping Practices in the Petroleum & Petrochemical Industries, Fifth Edition, July 2003 (Reaffirmed October 2010), Global StandardsLockout/Tagout
A process to specify that equipment is out of service until locks and/or tags are removed by the authorized person. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsLockout/Tagout
A procedure to control hazardous energy. Source: API RP 74, Recommended Practice for Occupational Safety for Onshore Oil and Gas Production Operation, First Edition, October 2001 (March 2007). Global StandardsWellsite
Definition(s)
Location
The point at which a well is to be drilled. Also referred to as “wellsite.” Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsLocation
Definition(s)
Location
Throughout this recommended practice, reference is made to areas, spaces, and locations. These terms should be considered interchangeable terms designating a three-dimensional space. API RP 500, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Division 1 and Division 2, Third Edition, December 2012, Global StandardsLocation
The point at which a well is to be drilled. Also referred to as “wellsite.” Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsLocation
A geographical site, area, country or region where an activity is taking place or an asset is situated. Source: IOGP Report No. 510, Operating Management System Framework for controlling risk and delivering high performance in the oil and gas industry, International Association of Oil & Gas Producers, June 2014. Global StandardsLocation
Location means a block or blocks in relation to which a declaration under section 131 is in force. Source: Offshore Petroleum and Greenhouse Gas Storage Act 2006, Australia, amended 2012. LegislationLocation
Location: the route, depth and stability. Source: Mining Decree of the Netherlands, Netherlands, 2003 (as amended in 2007). LegislationLoad Guylines
Definition(s)
Load Guylines
Stabilizing guylines that run from a point on the mast, derrick, or pole to a point at or near the base supporting the mast or pole or to ground anchors. (Sometimes referred to as “internal guylines” when attached to the base.) Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsLiner
Definition(s)
Liner
Continuous resin-rich coating on the inside surface of a pipe or fitting component, used to protect the laminate from chemical attack or to prevent leakage under stress.- Note: 1 to entry: The liner can also be used to provide enhanced abrasion and erosion resistance.
Liner
“Liner” means a continuous, low-permeability layer constructed of natural or human-made materials that restricts the migration of liquid oil field wastes, gases or leachate. Source: Oil and Gas, New Mexico Administrative Code Title 19, Chapter 15, January 2013. RegulationsLiner
"Liner" means a length of casing used downhole as an extension to a previously installed casing string to case the hole for further drilling operations and/or for producing operations. Source: Corporation Commission, Oil and Gas Conservation, Oklahoma Administrative Code 165:10, February 2013. RegulationsLiner
“Liner” means a string of casing set and cemented which does not extend to surface. Liners are anchored or suspended inside the previous casing string and may serve the purpose of intermediate or production casing strings. Source: Division of Mineral Resources Management - Oil and Gas, Ohio Administrative Code, Chapter 1501:9, January 2012. RegulationsLiner
A liner is a casing string that does not extend to the top of the well or to the wellhead. Liners are anchored or suspended from inside the previous casing string using a liner hanger. The liner can be fitted with special components so that it can be connected or tied back to the surface at a later time. Source: API STD 65 – Part 2, Isolating Potential Flow Zones During Well Construction, Upstream Segment, Second Edition, December 2010. Global StandardsLiner
Pipe that does not extend from the surface and is intended to line the walls of a drilled well. Source: API SPEC 11D1, Packers and Bridge Plugs, Upstream Segment, Second Edition, July 2009. Global StandardsLiner
See casing. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsLiner
A string of casing which does not extend to the surface but is hung from inside the previous casing string and is cemented in place. The overlap of the liner could vary from 50 ft to 500 ft depending on the purpose of the liner. Production liners are set to the top of, or through, the completion interval. Drilling liners are set primarily to case off and isolate zones of lost circulation, highly overpressured zones, and sloughing shales, so drilling may proceed. Repair liners are used to isolate casing leaks and to repair damaged, worn, corroded, or deliberately perforated casing. A large number of wells are drilled without running liners. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global StandardsLanyard
Definition(s)
Lanyard
A flexible line of rope, wire rope, or strap which generally has a connector at each end for connecting the body belt or body harness to a deceleration device, lifeline or anchorage. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global Standards Source: API RP 74, Recommended Practice for Occupational Safety for Onshore Oil and Gas Production Operation, First Edition, October 2001 (March 2007). Global StandardsLanyard
A flexible line to secure a wearer of a safety belt or harness to a drop line, lifeline, or fixed anchorage. Source: Petroleum Safety Orders--Drilling and Production, Definitions, California Code of Regulations, 8 CCR § 6505, December 2012. RegulationsUpper Kelly Valve
Definition(s)
Kelly swivel valve (kelly cock or upper kelly valve)
A valve located between the kelly swivel and the kelly, used for well control when the kelly is in the hole. It works like a check valve when engaged. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsKelly Cock
Definition(s)
Kelly Swivel Valve (Kelly Cock or Upper Kelly Valve)
A valve located between the kelly swivel and the kelly, used for well control when the kelly is in the hole. It works like a check valve when engaged. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsKelly Cock
A valve immediately above the kelly that can be closed to confine pressures inside the drill string. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global StandardsKelly Cock (Kelly Valve)
Valves installed immediately above and below the kelly that can be closed to confine pressures inside the drill string. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global StandardsKelly Cock
Valve installed between the swivel and the Kelly to prevent high-pressure backflow. Closing the valve keeps pressure off the swivel and rotary hose. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsKelly Cock
A valve installed at one or both ends of the kelly that can be used to confine pressure inside the drill string. Source: Petroleum Safety Orders--Drilling and Production, Definitions, California Code of Regulations, 8 CCR § 6505, December 2012. RegulationsKelly Swivel Valve
Definition(s)
Kelly swivel valve (kelly cock or upper kelly valve)
A valve located between the kelly swivel and the kelly, used for well control when the kelly is in the hole. It works like a check valve when engaged. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsHydraulic Fracturing
Definition(s)
Hydraulic Fracturing
The act of pumping fluid(s) into a wellbore and into a specific formation to induce fractures. The fluid usually carries some type of proppant material, such as sand, to keep the fracture open after pumping ceases. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsHydraulic Fracturing
Injecting fracturing fluids into the target formation at a force exceeding the parting pressure of the rock, thus inducing fractures through which oil or natural gas can flow to the wellbore. Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global StandardsHydraulic Fracturing
“Hydraulic fracturing” means the act of pumping fluids into a wellbore and into a specific formation to induce fractures. [Mich. Admin. Code R 408 (2013)]. Source: Oil and Gas Drilling and Servicing Operations, Michigan Administrative Code R 408, February 8, 2013. RegulationsPipe Tapping
Definition(s)
Hot Tapping (Pipe Tapping)
The act of drilling a hole through the wall of pipe that is under pressure. A special saddle is used to attach a valve and lubricator to the pipe. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsHot Tapping (Pipe Tapping)
The process of drilling a hole through the wall of pipe that is under pressure. A special saddle is used to attach a valve and lubricator to the pipe. Source: API RP 74, Recommended Practice for Occupational Safety for Onshore Oil and Gas Production Operation, First Edition, October 2001 (March 2007). Global StandardsHot Tapping (Pipe Tapping)
“Pipe tapping,” sometimes called hot tapping, means the act of drilling a hole in the side of pipe that is under pressure. [Mich. Admin. Code R 408 (2013)]. Source: Oil and Gas Drilling and Servicing Operations, Michigan Administrative Code R 408, February 8, 2013. RegulationsHot Tapping
Definition(s)
Hot tapping (pipe tapping)
The technique of attaching a mechanical or welded branch fitting to piping or equipment in service, and creating an opening in that piping or equipment by drilling or cutting a portion of the piping or equipment within the attached fitting. API RP 2201, Safe Hot Tapping Practices in the Petroleum & Petrochemical Industries, Fifth Edition, July 2003 (Reaffirmed October 2010), Global StandardsHot tapping (pipe tapping)
The act of drilling a hole through the wall of pipe that is under pressure. A special saddle is used to attach a valve and lubricator to the pipe. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsHot tapping (pipe tapping)
The process of drilling a hole through the wall of pipe that is under pressure. A special saddle is used to attach a valve and lubricator to the pipe. Source: API RP 74, Recommended Practice for Occupational Safety for Onshore Oil and Gas Production Operation, First Edition, October 2001 (March 2007). Global StandardsHot Oil Treatment
Definition(s)
Hot oil treatment
The act of heating oil and pumping it into the piping, tubing, casing, or formation to remove paraffin and asphaltines. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsHot oil treatment
The process of heating oil and pumping it into piping, tubing, casing, or a formation to remove paraffin. Source: API RP 74, Recommended Practice for Occupational Safety for Onshore Oil and Gas Production Operation, First Edition, October 2001 (March 2007). Global StandardsHazardous Substance
Definition(s)
Hazardous Substance
Any substance that, by reason of being explosive, flammable, toxic, corrosive, oxidizing, imitating, or otherwise harmful, has the potential to cause injury, illness, or death. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global Standards Source: API RP 74, Recommended Practice for Occupational Safety for Onshore Oil and Gas Production Operation, First Edition, October 2001 (March 2007). Global StandardsHazardous Substance
A chemical, biological or physical agent that, by reason of a property that the agent possesses, is hazardous to the safety or health of a person exposed to it. Note: OSH (NL) 1.1; OSH (NS) Element 1, Part 1, Section 1.1. Source: Incident Reporting and Investigation Guidelines, The Canada-Nova Scotia Offshore Petroleum Board and Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada, November 30, 2012. Regulatory GuidanceHazardous Substance
“Hazardous substance” means a controlled product and a chemical, biological or physical agent that, by reason of a property that the agent possesses, is hazardous to the safety or health of a person exposed to it. Source: Nova Scotia Offshore Petroleum Occupational Health & Safety Requirements, Canada-Nova Scotia Offshore Petroleum Board, Canada, December 2000. RegulationsHazardous Substance
Hazardous substance means a substance:- that is described in the List of Designated Hazardous Substances [NOHSC:10005(1999)] published by the Australian Safety and Compensation Council, as existing from time to time; or
- that has been determined, in writing, to be a hazardous substance by its manufacturer in accordance with the Approved Criteria for Classifying Hazardous Substances [NOHSC:1008(2004)] published by the Australian Safety and Compensation Council, as existing from time to time; or
- that is mentioned in Part 3 of Schedule 3.2.
Hazardous substance
One which is likely to cause injury by reason of being explosive, flammable, extremely flammable, poisonous, corrosive, oxidizing, irritant, or otherwise harmful. Source: Petroleum Safety Orders--Drilling and Production, Definitions, California Code of Regulations, 8 CCR § 6505, December 2012. RegulationsHazardous substance
"Hazardous Substance" means a substance which, by reason of being explosive, flammable, poisonous, corrosive, oxidizing, irritating, or otherwise harmful, is likely to cause occupational death, injury or illness. Source: State of Wyoming Occupational Safety and Health Rules and Regulations for Oil and Gas Well Drilling, Revised January 8, 2013. RegulationsHazardous substance
A substance which by virtue of its chemical, physical, biological or toxicological properties constitutes a hazard. Source: Approved Code of Practice for Managing Hazards to Prevent Major Industrial Accidents, Health and Safety in Employment Act 1992, Department of Labour, New Zealand, July 1994. Regulatory GuidanceGuyline Anchors
Definition(s)
Guyline anchors
The ground components of the guyline system to which the wire rope(s) is attached. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsGuyline
Definition(s)
Guyline
Wire rope(s) that is attached to elevated structures, such as derricks or mast, and ground anchors for stability. See API Recommended Practices 4A, 4D, 4E, 4F, 4G, and 9B. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsFlammable Liquid
Definition(s)
Flammable Liquid (Class MIII, and Class IC liquids)
A liquid having a flash point below l00°F (37.8°C) and having a vapor pressure not exceeding 40 lb per sq. in. absolute (276 kilopascals) at l00°F (37.8°C). Flammable (Class 1) liquids are subdivided into Classes IA, IB, and IC. (See NFPA 30.) Source: API RP 14G, Recommended Practice for Fire Prevention and Control on Fixed Open-type Offshore Production Platforms: Upstream Segment, Fourth Edition, April 2007. Global StandardsFlammable liquid
Any liquid having a flashpoint below 100 °F (373 °C). Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global Standards Source: API RP 74, Recommended Practice for Occupational Safety for Onshore Oil and Gas Production Operation, First Edition, October 2001 (March 2007). Global StandardsFlammable Liquid
Liquid capable of producing a flammable vapour under any foreseeable operating conditions. Source: IEC 61892-7, Mobile and fixed offshore units – Electrical installations – Part 7: Hazardous areas. Global StandardsFlammable Liquid
A liquid having a flash point below 100oF., (37.8oC) and having a vapor pressure not exceeding 40 lb. per sq. in. (absolute) (176 kPa) at 100oF (37.8oC) and shall be known as Class I liquid. Class I Liquids shall be subdivided as follows: Class IA shall include those having flash points below 73oF., (22.8oC.) and having a boiling point below 100oF., (37.8oC.). Class IB shall include those having flash points below 73oF., (22.8oC.) and having a boiling point at or above 100oF., (37.8oC.). Class IC shall include those having flash points at or above 73oF., (22.8oC.) and below 100oF., (37.8oC.). Source: Petroleum Safety Orders--Drilling and Production, Definitions, California Code of Regulations, 8 CCR § 6505, December 2012. RegulationsFlammable Liquid
"Flammable liquid" means any liquid having a flashpoint below 100°F. (37.8°C.), except any mixture having components with flash-points of 100°F. ( 37.8°C) or higher, the total of which make up ninety-nine (99) percent or more of the total volume of the mixture. Flammable liquids shall be known as Class I liquids. Class I liquids are divided into three classes as follows:- Class IA shall include liquids having flashpoints below 73°F. (22.8°C.) and having a boiling point below 100°F. (37.8°C.). Example: LPG.
- Class IB shall include liquids having flashpoints below 73°F. (22.8°C.) and having a boiling point at or above 100°F. (37.8°C.) Example: Acetone, Methyl Ethyl Ketone.
- Class IC shall include liquids having flashpoints at or above 73°F. (22.8°C.) and below 100°F. (37.8°C.). Example: Turpentine.6