Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
District Office
Definition(s)
District Office
The commission-designated office for the geographic area in which the property or act subject to regulation is located or arises. Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsCubic Foot Of Gas Or Standard Cubic Foot Of Gas
Definition(s)
Cubic Foot Of Gas Or Standard Cubic Foot Of Gas
The volume of gas contained in one cubic foot of space at a standard pressure base and at a standard temperature base. The standard pressure base shall be 14.65 pounds per square inch absolute, and the standard temperature base shall be 60 degrees Fahrenheit. Whenever the conditions of pressure and temperature differ from the standard in this definition, conversion of the volume from these conditions to the standard conditions shall be made in accordance with the ideal gas laws, corrected for deviation. Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsCommon Reservoir
Definition(s)
Common Reservoir
Any oil, gas, or geothermal resources field or part thereof which comprises and includes any area which is underlaid, or which from geological or other scientific data or experiments or from drilling operations or other evidence appears to be underlaid by a common pool or accumulation of oil, gas, or geothermal resources. Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsBy-Product
Definition(s)
By-Product
Any element found in a geothermal formation which when brought to the surface is not used in geothermal heat or pressure inducing energy generation. Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsAdjacent Estuarine Zones
Definition(s)
Adjacent Estuarine Zones
This term embraces the area inland from the coast line of Texas and is comprised of the bays, inlets, and estuaries along the gulf coast. Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsWorkable Coal Seam
Definition(s)
Workable Coal Seam
Workable coal seam—One of the following:- A coal seam in fact being mined in the area in question under the act and this chapter by underground methods.
- A coal seam which, in the judgment of the Department, reasonably can be expected to be mined by underground methods.
Well Operator
Definition(s)
Well Operator
Company that has responsibility for the well. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global StandardsWell Operator
Well operator or operator—The person designated as the well operator or operator on the permit application or well registration. If a permit or registration was not issued, the term means a person who locates, drills, operates, alters or plugs a well or reconditions a well with the purpose of production therefrom. In cases where a well is used in connection with the underground storage of gas, the term also means a storage operator. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsWell Operator
"Well operator" means a person as herein defined who has the responsibility, management, and general control of an oil or gas well, or lessee, sub-lessee, owner or assignee of same. Source: State of Wyoming Occupational Safety and Health Rules and Regulations for Oil and Gas Well Drilling, Revised January 8, 2013. RegulationsWell Operator
“well operator”, in relation to a well or proposed well, means—- the person appointed by the licensee for that well or proposed well to execute the function of organising and supervising the drilling of that well and all operations to be carried out by means of that well; or
- where no such person has been appointed, the licensee.
Well Operator
Well operator, in relation to a well or proposed well, means— (a) the employer appointed by the permit operator to perform the function of organising and supervising— (i) the drilling of that well; and (ii) all operations to be carried out by means of that well; or (b) the permit operator, if the permit operator is an employer of employees at the well site and— (i) no employer is appointed; or (ii) the permit operator has notified the appointed employer in writing that the permit operator is to be treated as the well operator for the purposes of these regulations. Source: Health and Safety in Employment (Petroleum Exploration and Extraction) Regulations 2013, SR 2013/208, New Zealand, as of May 2013. RegulationsWater Supply
Definition(s)
Water Supply
The total water available for use on a project. Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global StandardsWater Supply
Water supply—A supply of water for human consumption or use, or for agricultural, commercial, industrial or other legitimate beneficial uses. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsWater Purveyor
Definition(s)
Water Purveyor
Water purveyor—The owner or operator of a public water supply. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsWater Protection Depth
Definition(s)
Water Protection Depth
Water protection depth—The depth to a point 50 feet below the surface casing seat. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsUnconventional Formations
Definition(s)
Unconventional Formations
Unconventional formations—Formations that typically produce gas through the use of enhanced drilling or completion technologies such as the Rhinestreet, Burket, Marcellus, Mandata and Utica Shale formations, or other formations identified by the Department. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsTotal Depth
Definition(s)
Total Depth
Total depth—The depth to which the well was originally drilled, subsequently drilled or the depth to which it was plugged back in a manner approved by the Department. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsTophole Water
Definition(s)
Tophole Water
Tophole water—Water that is brought to the surface while drilling through the strata containing fresh groundwater and water that is fresh groundwater or water that is from a body of surface water. Tophole water may contain drill cuttings typical of the formation being penetrated but may not be polluted or contaminated by additives, brine, oil or man induced conditions. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsSoil Mottling
Definition(s)
Soil Mottling
Soil mottling—Irregular marked spots in the soil profile that vary in color, size and number. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsSheen
Definition(s)
Sheen
Very thin layer of oil (less than 0.0002 in. or 0.005 mm) floating on the water surface; this is the most common form of oil seen in the later stages of a spill. NOTE According to their thickness, sheens vary in color from rainbows (for the thicker layers) to silver/gray (for thinner layers) to almost transparent (for the thinnest layers). Source: API RP 98, Personal Protective Equipment Selection for Oil Spill Responders, First Edition, August 2013. Global StandardsSheen
Sheen—An iridescent appearance on the surface of the water. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsSeasonal High Groundwater Table
Definition(s)
Seasonal High Groundwater Table
Seasonal high groundwater table—The saturated condition in the soil profile during certain periods of the year. The condition can be caused by a slowly permeable layer within the soil profile and is commonly indicated by the presence of soil mottling. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsRetrievable
Definition(s)
Retrievable
Retrievable—When used in conjunction with surface casing, coal protective casing or production casing, the casing that can be removed after exerting a prudent effort to pull the casing while applying a pulling force at least equal to the casing weight plus 5000 pounds or 120% of the casing weight, whichever is greater. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsReportable Release Of Brine
Definition(s)
Reportable Release Of Brine
Reportable release of brine—Spilling, leaking, emitting, discharging, escaping or disposing of one of the following:- More than 5 gallons of brine within a 24-hour period on or into the ground at the well site where the total dissolved solids concentration of the brine is equal or greater than 10,000 mg/l.
- More than 15 gallons of brine within a 24-hour period on or into the ground at the well site where the total dissolved solids concentration of the brine is less than 10,000 mg/l.1
Public Water Supply
Definition(s)
Public Water Supply
Public water supply—A water system that is subject to the Pennsylvania Safe Drinking Water Act (35 P. S. § § 721.1—721.17). Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsPrivate Water Supply
Definition(s)
Private Water Supply
Private water supply—A water supply that is not a public water supply. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsPermanently Cemented
Definition(s)
Permanently Cemented
Permanently cemented—Surface casing or coal protective casing that is cemented until cement is circulated to the surface or is cemented with a calculated volume of cement necessary to fill the theoretical annular space plus 20% excess. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsPerimeter Area
Definition(s)
Perimeter Area
Perimeter area—An area that begins at the outside coal boundaries of an operating coal mine and extends within 1000 feet beyond those boundaries or an area within 1000 feet beyond the mine permit boundaries of a coal mine already projected and permitted but not yet being operated. Source: Oil and Gas Wells, Pennsylvania Code, Title 25, Chapter 78, December 2012. RegulationsObservation 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.