Texas Administrative Code

TITLE 16 ECONOMIC REGULATION

PART 1 RAILROAD COMMISSION OF TEXAS

CHAPTER 3 OIL AND GAS DIVISION

RULE §3.79 Definitions

The following words and terms, when used in this chapter, shall have the following meanings, 

unless the context clearly indicates otherwise. 

 (1) 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. 

 (2) 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. 

 (3) Casinghead gas--Any gas or vapor, or both, indigenous to an oil stratum and produced 

from such stratum with oil. 

 (4) Commission--The Railroad Commission of Texas. 

 (5) 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. 

 (6) 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. 

 (7) District office--The commission-designated office for the geographic area in which the 

property or act subject to regulation is located or arises. 

 (8) Dry gas--Any natural gas produced from a stratum that does not produce crude petroleum 

oil. 

 (9) Exploratory well--Any well drilled for the purpose of securing geological or geophysical 

information to be used in the exploration or development of oil, gas, geothermal, or other 

mineral resources, except coal and uranium, and includes what is commonly referred to in the 

industry as "slim hole tests," "core hole tests," or "seismic holes." For regulations governing 

coal exploratory wells, see Chapter 12 of this title (relating to Coal Mining Regulations), and 

for regulations governing uranium exploratory wells, see Chapter 11, Subchapter C of this title 

(relating to Surface Mining and Reclamation Division, Substantive Rules--Uranium Mining). 

 (10) Gas lift--Gas lift by the use of gas not in solution with oil produced. 

 (11) Gas well--Any well: 

 (A) which produces natural gas not associated or blended with crude petroleum oil at the time 

of production; 

 (B) which produces more than 100,000 cubic feet of natural gas to each barrel of crude 

petroleum oil from the same producing horizon; or 
 (C) which produces natural gas from a formation or producing horizon productive of gas only 

encountered in a wellbore through which crude petroleum oil also is produced through the 

inside of another string of casing or tubing. A well which produces hydrocarbon liquids, a part 

of which is formed by a condensation from a gas phase and a part of which is crude petroleum 

oil, shall be classified as a gas well unless there is produced one barrel or more of crude 

petroleum oil per 100,000 cubic feet of natural gas; and that the term "crude petroleum oil" shall 

not be construed to mean any liquid hydrocarbon mixture or portion thereof which is not in the 

liquid phase in the reservoir, removed from the reservoir in such liquid phase, and obtained at 

the surface as such. 

 (12) 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. 

 (13) Geothermal energy and associated resources--

 (A) All products of geothermal processes, embracing indigenous steam, hot water and hot 

brines, and geopressured water; 

 (B) Steam and other gases, hot water and hot brines resulting from water, gas, or other fluids 

artificially introduced into geothermal formations; 

 (C) Heat or other associated energy found in geothermal formations; 

 (D) Any by-product derived from them. 

 (14) Geothermal resource well--A well drilled within the established limits of a designated 

geothermal field. 

 (A) A geopressured geothermal well must be completed within a geopressured aquifer. 

 (B) A 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. 

 (15) 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. 

 (A) 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. 

 (B) 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. 

 (C) 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. 
 (D) 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. 

 (E) 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.) 

 (16) Natural gas or gas--These terms shall have the same meaning, as used in the rules, 

regulations, or forms of the commission. 

 (17) Natural gasoline--Gasoline manufactured from casinghead gas or from any natural gas. 

 (18) Oil well--Any well which produces one barrel or more crude petroleum oil to each 

100,000 cubic feet of natural gas. 

 (19) Operator--A person, acting for himself or as an agent for others and designated to the 

commission as the one who has the primary responsibility for complying with its rules and 

regulations in any and all acts subject to the jurisdiction of the commission. 

 (20) Person--Any natural person, corporation, association, partnership, receiver, trustee, 

guardian, executor, administrator, and a fiduciary or representative of any kind. 

 (21) Product--Includes refined crude oil, crude tops, topped crude, processed crude petroleum, 

residue from crude petroleum, cracking stock, uncracked fuel oil, fuel oil, treated crude oil, 

residuum, casinghead gasoline, natural gas gasoline, gas oil, naphtha, distillate, gasoline, 

kerosene, benzine, wash oil, waste oil, blended gasoline, lubricating oil, blends or mixtures of 

petroleum, and/or any and all liquid products or by-products derived from crude petroleum oil 

or gas, whether hereinabove enumerated or not. 

 (22) Sour gas--Any natural gas containing more than 1 1/2 grains of hydrogen sulphide per 

100 cubic feet or more than 30 grains of total sulphur per 100 cubic feet, or gas which in its 

natural state is found by the commission to be unfit for use in generating light or fuel for 

domestic purposes. 

 (23) Sweet gas--All natural gas except sour gas and casinghead gas. 

 (24) Texas offshore--This term embraces the area in the Gulf of Mexico seaward of the coast 

line of Texas comprised of: 

 (A) the three league area confirmed to the State of Texas by the Submerged Land Act (43 

United States Code §§1301-1315); and 

 (B) the area seaward of such three league area owned by the United States. 

 (25) Transportation or to transport--The movement of any crude petroleum oil or products of 

crude petroleum oil or the products of either from any receptacle in which any such crude 

petroleum or products of crude petroleum oil or the products of either has been stored to any 

other receptacle by any means or method whatsoever, including the movement by any pipeline, 

railway, truck, motor vehicle, barge, boat, or railway tank car. It is the purpose of this definition 

to include the movement or transportation of crude petroleum oil and products of crude 

petroleum oil and the products of either by any means whatsoever from any receptacle 

containing the same to any other receptacle anywhere within or from the State of Texas, 

regardless of whether or not possession or control or ownership change. 
 (26) Transporter or transporting agency--Includes any common carrier by pipeline, railway, 

truck, motor vehicle, boat, or barge, and/or any person transporting oil or a product by pipeline, 

railway, truck, motor vehicle, boat, or barge. 

 (27) Underground source of drinking water--An aquifer or its portion which is not an exempt 

aquifer as defined in 40 Code of Federal Regulations §146.4 and which: 

 (A) supplies any public water system; or 

 (B) contains a sufficient quantity of ground water to supply a public water system; and 

 (i) currently supplies drinking water for human consumption; or 

 (ii) contains fewer than 10,000 milligrams per liter (mg/l) total dissolved solids. 

Source Note: The provisions of this §3.79 adopted to be effective August 25, 2003, 28 TexReg 

6816; amended to be effective July 2, 2012, 37 TexReg 4892