Wyoming Administrative Code › Agency 037 - Engineer, State › Sub-Agency 0009 - Water Well Minimum Construction Standards › Chapter 2 - REQUIREMENTS AND DEFINITIONS › Section 2-2 - Definitions

Current through July 13, 2024
For the purposes of Part III of the Regulations and
				  Instructions of the Wyoming State Engineer's Office - Ground Water Division,
				  the following definitions apply:
(a)
				ACCESS PORT - An opening at the wellhead and/or within the discharge system
				where measuring devices or meters may be placed to measure water levels,
				pressure, or discharge.
(b)
				ACRE-FOOT - The volume of water required to cover one (1) acre to a depth of
				one (1) foot. One (1) acre-foot equals approximately 325,851 U.S.
				Gallons.
(c) AIR-HAMMER DRILLING -
				A system of drilling that employs a pneumatic bit that delivers percussion
				strikes to the formation while being slowly rotated. Cuttings are removed by
				the compressed air that drives the hammer bit.
(d) ALLUVIUM - Deposits resulting from the
				operations of rivers, streams, etc., thus including sediments laid down in
				riverbeds, flood plains, lakes, fans at the foot of mountain slopes, and
				estuaries.
(e) ANNULAR SPACE
				(ANNULUS) - The space between two cylindrical surfaces, one of which surrounds
				the other, e.g. concentrically; such as the space between the outer well casing
				and the borehole wall. An annular space also means the space between an inner
				well casing and outer well casing. The annular space is calculated as the
				difference in diameter of the borehole (Db) and the
				outside diameter of the casing (Dc) divided by two
				[(Db-Dc)/2], or the difference in
				the inside diameter of a larger casing (Di) and the
				outside diameter of a smaller casing (Ds) divided by 2
				[(Di-Ds)/2].
(f) AQUIFER - "Any underground geological
				structure or formation having boundaries that may be ascertained or reasonably
				inferred, in which water stands, flows or percolates." (W.S. §
									
										41-3-901(a)(iii) ). (Also
				see Unconfined, Confined and Perched)
(g) API - The American Petroleum
				Institute.
(h) ARTESIAN AQUIFER -
				See Confined Aquifer.
(i) ARTESIAN
				WELL - A well that derives its water from an artesian or confined aquifer where
				the hydrostatic pressure is greater than atmospheric pressure thereby raising
				the water level above the top of the aquifer. A flowing artesian well has a
				water level that is above the land surface.
(j) ASTM - American Society for Testing and
				Materials International.
(k) AWWA -
				The American Water Works Association
(l) BENTONITE - Clay composed predominantly
				of the clay mineral montmorillonite and used commercially in drilling fluids
				and well sealing products.
(m)
				BOREHOLE LOGS - Borehole logs measure and display the physical properties of
				the surrounding medium with a sensor located in a borehole. Some common
				borehole logging techniques are presented below:
(i) Acoustic (Sonic) Velocity - A borehole
				log in which the down-hole tooling has a sound transmitter at one end and two
				receivers spaced along it. The tool uses the difference in signal arrival time
				to calculate the sonic velocity through the strata.
(ii) Caliper - A borehole log which measures
				the size of the well bore. Used to measure the diameter of an uncased borehole
				in bedrock units. Can also be used to find the casing depth.
(iii) Cement Bond (Bond) - An acoustic log
				that measures and displays the return arrival time of an acoustic wave
				generated within the casing. When steel casing is strongly bonded to cement,
				most of the energy of the wave is carried through the casing; however, when the
				casing is not strongly bonded to the cement, most of the sound waves are
				carried along the casing and the arrival time will be much shorter.
(iv) Focused (Focus) - A borehole log wherein
				electrodes are designed to direct electrical current as a disk. This method can
				yield improved results in high resistivity strata.
(v) Formation Density (Density) - A borehole
				log which measures the rock density.
(vi) Gamma-Gamma Radiation - A borehole log
				in which a source of gamma radiation and a detector are lowered into the
				borehole. The log measures bulk density of the formation and fluids.
(vii) Gamma-Ray (or Gamma) - A borehole log
				which measures naturally occurring gamma radiation emitted by the surrounding
				strata.
(viii) Induction (or Dual
				Induction) - A borehole log which measures spontaneous potential, resistivity,
				and conductivity.
(ix) Neutron
				Porosity (Neutron) - A borehole log obtained by lowering a radioactive element,
				which is a source of neutrons, and a neutron detector into the well. The log
				measures the hydrogen atom density of the surrounding strata and provides an
				indication of the formation porosity.
(x) Resistivity - A borehole log which
				measures the resistivity between two current electrodes and two additional
				electrodes. Measures the electrical resistivity of the formation and contained
				fluids near the probe.
(xi)
				Spontaneous Potential (or Self Potential) (SP) - A borehole log made by
				measuring the natural electrical potential that develops between the formation
				and the borehole fluids. The SP log is commonly used to assess the permeability
				of the surrounding strata.