Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Observation Well
Definition(s)
Observation Well
Observation well—A well used to monitor the operational integrity and conditions in a gas storage reservoir, the reservoir protective area or strata above or below the gas storage horizon. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsNonvertical Well
Definition(s)
Nonvertical Well
Nonvertical well—- A well drilled intentionally to deviate from a vertical axis.
- The term includes wells drilled diagonally and wells that have horizonal bore holes.
Nonporous Material
Definition(s)
Nonporous Material
Nonporous material—Nontoxic earthen mud, drill cuttings, fire clay, gel, cement or equivalent materials approved by the Department that will equally retard the movement of fluids. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsNoncoal Area
Definition(s)
Noncoal Area
Noncoal area—An area that is not underlain by a workable coal seam. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsNoncementing Material
Definition(s)
Noncementing Material
Noncementing material—A mixture of very fine to coarse grained nonbonding materials, including unwashed crushed rock, drill cuttings, earthen mud or other equivalent material approved by the Department. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsMarcellus Shale Well
Definition(s)
Marcellus Shale Well
Marcellus Shale well—A well that when drilled or altered produces gas or is anticipated to produce gas from the Marcellus Shale geologic formation. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsL.E.L.
Definition(s)
L.E.L.
L.E.L.—Lower explosive limit. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsGel
Definition(s)
Gel
Gel—A slurry of clay or other equivalent material and water at a ratio of not more than 7 barrels of water to each 100 pounds of clay or other equivalent matter. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsGas Storage Reservoir
Definition(s)
Gas Storage Reservoir
Gas storage reservoir—The portion of a subsurface geologic formation or rock strata used for or being tested for storage of natural gas that:- Has sufficient porosity and permeability to allow gas to be injected or withdrawn, or both.
- Is bounded by strata of insufficient porosity or permeability, or both, to allow gas movement out of the reservoir.
- Contains or will contain injected gas geologically or by pressure control.
Gas Storage Field
Definition(s)
Gas Storage Field
Gas storage field—A gas storage reservoir and all of the gas storage wells connected to the gas storage reservoir. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsFresh Groundwater
Definition(s)
Fresh Groundwater
Fresh groundwater—Water in that portion of the generally recognized hydrologic cycle which occupies the pore spaces and fractures of saturated subsurface materials. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsDrill Cuttings
Definition(s)
Drill Cuttings
Drill cuttings—Rock cuttings and related mineral residues generated during the drilling of an oil or gas well. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsDeepest Fresh Groundwater
Definition(s)
Deepest Fresh Groundwater
Deepest fresh groundwater—The deepest fresh groundwater bearing formation penetrated by the wellbore as determined from drillers logs from the well or from other wells in the area surrounding the well or from historical records of the normal surface casing seat depths in the area surrounding the well, whichever is deeper. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsCoal Protective Casing
Definition(s)
Coal Protective Casing
Coal protective casing—A string of pipe which is installed in the well for the purpose of coal segregation and protection. In some instances the coal protective casing and the surface casing may be the same. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsCoal Area
Definition(s)
Coal Area
Coal area—An area that is underlain by a workable coal seam. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsWell Approval
Definition(s)
Well Approval
“Well approval” means the approval granted by the Board under section 13 (approbation relative à un puits). Source: Canada Oil and Gas Drilling and Production Regulations, SOR/2009-315, February 2013. Regulations Source: Drilling and Production Guidelines, The Canada-Nova Scotia Offshore Petroleum Board and Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada, March 31, 2011. Regulatory Guidance Source: Nova Scotia Offshore Petroleum Drilling and Production Regulations, SOR/2009-317, Canada, current to May 31, 2012. RegulationsCertified Laboratory
Definition(s)
Certified Laboratory
Certified laboratory—A laboratory accredited by the Department under Chapter 252 (relating to laboratory accreditation). Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsCement Job Log
Definition(s)
Cement Job Log
Cement job log—A written record that documents the actual procedures and specifications of the cementing operation. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsWaste Material
Definition(s)
Waste Material
“Waste material” means any garbage, refuse, sewage or waste well fluids or any other useless material that is generated during drilling, well or production operations, including used or surplus drilling fluid and drill cuttings and produced water (déchets). Source: Canada Oil and Gas Drilling and Production Regulations, SOR/2009-315, February 2013. Regulations Source: Drilling and Production Guidelines, The Canada-Nova Scotia Offshore Petroleum Board and Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada, March 31, 2011. Regulatory Guidance Source: Environmental Protection Plan Guidelines, The Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada-Nova Scotia Offshore Petroleum Board, and National Energy Board, Canada, March 31, 2011. Regulatory Guidance Source: Offshore Waste Treatment Guidelines, The Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada-Nova Scotia Offshore Petroleum Board, and National Energy Board, Canada, December 15, 2010. Regulatory Guidance Source: Nova Scotia Offshore Petroleum Drilling and Production Regulations, SOR/2009-317, Canada, current to May 31, 2012. RegulationsCasing Seat
Definition(s)
Casing Seat
Casing seat—The depth to which casing is set. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsAttainable Bottom
Definition(s)
Attainable Bottom
Attainable bottom—The depth, approved by the Department, which can be achieved after a reasonable effort is expended to clean out to the total depth. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsWell Log Or Well Record
Definition(s)
Well Log Or Well Record
"Well log" or "well record" means a systematic, detailed and correct record of formations encountered in the drilling of a well. Source: Corporation Commission, Oil and Gas Conservation, Oklahoma Administrative Code 165:10, February 2013. RegulationsWaste Oil Residue
Definition(s)
Waste Oil Residue
"Waste oil residue" means that portion of waste oil remaining after treatment and after the saleable liquids and water have been extracted. Waste oil residue is a type of waste oil. Source: Corporation Commission, Oil and Gas Conservation, Oklahoma Administrative Code 165:10, February 2013. RegulationsWaste Oil
Definition(s)
Waste Oil
"Waste oil" shall include, but not be limited to, crude oil or other hydrocarbons used or produced in the process of drilling for, developing, producing, or processing oil or gas from wells, oil retained on cuttings as a result of the use of oil-based drilling muds, or any residue from any oil storage facility on a producing lease or on a commercial disposal operation or pit. The term "waste oil" shall not include any refined hydrocarbons to which lead has been added. Source: Corporation Commission, Oil and Gas Conservation, Oklahoma Administrative Code 165:10, February 2013. RegulationsWaste Oil
Waste oil as mentioned in the third subsection, means used lubricants and similar oils (used in engines, gear boxes, hydraulic systems, transformers, switches etc.) that can no longer be used as originally intended. Source: Guidelines Regarding the Activities Regulations, Norway, updated December 2012. Regulatory GuidanceWaster
Definition(s)
Waster
"Waste" means:- As applied to the production of oil, in addition to its ordinary meaning, "shall include economic waste, underground waste, including water encroachment in the oil or gas bearing strata; the use of reservoir energy for oil producing purposes by means or methods that unreasonably interfere with obtaining from the common source of supply the largest ultimate recovery of oil; surface waste and waste incident to the production of oil in excess of transportation or marketing facilities or reasonable market demands." [52 O.S.A., 86.2]
- As applied to gas, in addition to its ordinary meaning, shall include economic waste; "the inefficient or wasteful utilization of gas in the operation of oil wells drilled to and producing from a common source of supply; the inefficient or wasteful utilization of gas in the operation of gas wells drilled to and producing from a common source of supply; the production of gas in such quantities or in such manner as unreasonably to reduce reservoir pressure or unreasonably to diminish the quantity of oil or gas that might be recovered from a common source of supply; the escape, directly or indirectly, of gas from oil wells producing from a common source of supply into the open air in excess of the amount necessary in the efficient drilling, completion or operation thereof; waste incident to the production of natural gas in excess of transportation and marketing facilities or reasonable market demand; the escape, blowing, or releasing, directly or indirectly, into the open air, of gas from well productive of gas only, drilled into any common source of supply, save only such as is necessary in the efficient drilling and completion thereof; and the unnecessary depletion or inefficient utilization of gas energy contained in a common source of supply." [52 O.S.A. §86.3]
- The use of gas for the manufacture of carbon black or similar products predominately carbon, except as specifically authorized by the Commission, shall constitute waste.
- The flaring of tail gas at gasoline, pressure maintenance, or recycling plants where a market is available.