18 CFR 270.305 - Determination of tight formation areas.
(a) General requirement. A jurisdictional agency determination designating a portion of a formation as a tight formation must be made in the form and manner prescribed in this subpart.
(b) Guidelines for designating tight formations. A jurisdictional agency determination designating a portion of a formation as a tight formation must be made in accordance with the following guidelines:
(1) Within the geographic boundaries of the portion of the formation being recommended for tight formation designation, the estimated in situ gas permeability, throughout the pay section, is expected to be 0.1 millidarcy (md) or less. The expected in situ permeability is to be determined through an arithmetic mean averaging of the known permeabilities obtained from the wells that penetrate, and have a pay section in, such portion of such formation.
(2) Within the geographic boundaries of the portion of the formation being recommended for tight formation designation, the stabilized production rate of natural gas, against atmospheric pressure, of wells completed for production in such portion of such formation, without stimulation, is not expected to exceed the production rate determined in accordance with the table in this paragraph (b)(2). Such expected stabilized, pre-stimulation production rate is to be determined through an arithmetic mean averaging of the known stabilized, pre-stimulation production rates obtained from the wells that penetrate, and have a pay section in, such portion of such formation.
|If the average depth to the top of the formation (in feet)||The maximum allowable production rate of natural gas (in Mcf per day)|
|exceeds -||but does not
|may not exceed -|
(c) Notice to the Commission. Any jurisdictional agency making a determination that a formation, or portion thereof, qualifies as a tight formation will provide timely notice, in writing, of such determination, to the Commission. Such notice shall include the following to substantiate the jurisdictional agency's findings:
(1) Geological and geographical descriptions of the formation, or portion thereof, which is determined to qualify as a tight formation; and
(2) Geological and engineering data to support the determination, including (but not limited to):
(i) A map of the area for which a tight formation determination is being sought that clearly locates and identifies all data wells and all dry holes that penetrate the subject formation and all wells that are currently producing from the subject formation.
(ii) A well-by-well table of each in situ permeability value (in millidarcies), pre-stimulation stabilized production rate (in Mcf per day), and depth to the top of the formation (in feet) for each well, and the arithmetic mean of each set of data.
(iii) For any data that the jurisdictional agency excludes from the above calculations, a statement explaining why the data was excluded.
(iv) The underlying well test, well logs, cross-sections, or other data sources, and all calculations performed to derive the formation tops, permeability values, and pre-stimulation stabilized production rates shown in the well-by-well table.
(v) Any other information that the jurisdictional agency deems relevant and/or that the jurisdictional agency relied upon in making its determination.