Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Texas Offshore
Definition(s)
Texas Offshore
This term embraces the area in the Gulf of Mexico seaward of the coast line of Texas comprised of:- the three league area confirmed to the State of Texas by the Submerged Land Act (43 United States Code §§1301-1315); and
- the area seaward of such three league area owned by the United States.
Sweet Gas
Definition(s)
Sweet Gas
Natural gas that does not contain hydrogen sulfide gas. Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global StandardsSweet Gas
All natural gas except sour gas and casinghead gas. Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsNatural Gasoline
Definition(s)
Natural Gasoline
Gasoline manufactured from casinghead gas or from any natural gas. Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsMarginal Well
Definition(s)
Marginal Well
Any oil well which is incapable of producing its maximum capacity of oil except by pumping, gas lift, or other means of artificial lift, and which well so equipped is capable, under normal unrestricted operating conditions, of producing such daily quantities of oil as herein set out, as would be damaged, or result in a loss of production ultimately recoverable, or cause the premature abandonment of same, if its maximum daily production were artificially curtailed. The following described wells shall be deemed "marginal wells" in this state.- Any oil well incapable of producing its maximum daily capacity of oil except by pumping, gas lift, or other means of artificial lift, within this state and having a maximum daily capacity for production of 10 barrels or less, averaged over the preceding 10 consecutive days of stabilized production, producing from a depth of 2,000 feet or less.
- Any oil well incapable of producing its maximum daily capacity of oil except by pumping, gas lift, or other means of artificial lift, within this state and having a maximum daily capacity for production of 20 barrels or less, averaged over the preceding 10 consecutive days of stabilized production, producing from a horizon deeper than 2,000 feet and less in depth than 4,000 feet.
- Any oil well incapable of producing its maximum daily capacity of oil except by pumping, gas lift, or other means of artificial lift, within this state and having a maximum daily capacity for production of 25 barrels or less, averaged over the preceding 10 consecutive days of stabilized production, producing from a horizon deeper than 4,000 feet and less in depth than 6,000 feet.
- Any oil well incapable of producing its maximum daily capacity of oil except by pumping, gas lift, or other means of artificial lift, within this state and having a maximum daily capacity for production of 30 barrels or less, averaged over the preceding 10 consecutive days of stabilized production, producing from a horizon deeper than 6,000 feet and less in depth than 8,000 feet.
- Any oil well incapable of producing its maximum daily capacity of oil except by pumping, gas lift, or other means of artificial lift, within this state and having a maximum daily capacity for production of 35 barrels or less, averaged over the preceding 10 consecutive days of stabilized production, producing from a horizon deeper than 8,000 feet. (Reference Order Number 20-59,200, effective May 1, 1969.).1
Geothermal Resource Well
Definition(s)
Geothermal Resource Well
A well drilled within the established limits of a designated geothermal field.- A geopressured geothermal well must be completed within a geopressured aquifer.
- geopressured aquifer is a water-bearing zone with a pressure gradient in excess of 0.5 pounds per square inch per foot and a temperature gradient in excess of 1.6 degrees Fahrenheit per 100 feet of depth.
Geothermal Energy And Associated Resources
Definition(s)
Geothermal Energy And Associated Resources
Geothermal energy and associated resources include- All products of geothermal processes, embracing indigenous steam, hot water and hot brines, and geopressured water;
- Steam and other gases, hot water and hot brines resulting from water, gas, or other fluids artificially introduced into geothermal formations;
- Heat or other associated energy found in geothermal formations;
- Any by-product derived from them.
Geothermal Energy And Associated Resources
Geothermal energy and associated resources as defined in Texas Natural Resources Code, §141.003(4). Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsGatherer
Definition(s)
Gatherer
Includes any pipeline, truck, motor vehicle, boat, barge, or person authorized to gather or accept oil, gas, or geothermal resources from lease production or lease storage. Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsDry Gas
Definition(s)
Dry Gas
Natural gas composed mainly of methane with only minor amounts of ethane, propane, butane, and minimum heavier hydrocarbons in the gasoline range. Source: IADC UBO / MPD Glossary, December 2011. Global StadandardsDry Gas
Any natural gas produced from a stratum that does not produce crude petroleum oil. Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsDistrict 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