Current through Register Vol. 35, No. 18, September 24, 2024
A. "ANSI" means the
American national standards institute.
B. "Area of exposure" means the area within a
circle constructed with a point of escape at its center and the radius of
exposure as its radius.
C.
"Dispersion technique" is a mathematical representation of the physical and
chemical transportation characteristics, dilution characteristics and
transformation characteristics of hydrogen sulfide gas in the
atmosphere.
D. "Escape rate" means
the maximum volume (Q) that is used to designate the possible rate of escape of
a gaseous mixture containing hydrogen sulfide, as set forth in 19.15.11 NMAC.
(1) For existing gas facilities or
operations, the escape rate is calculated using the maximum daily rate of the
gaseous mixture produced or handled or the best estimate thereof. For an
existing gas well, the escape rate is calculated using the current daily
absolute open flow rate against atmospheric pressure or the best estimate of
that rate.
(2) For new gas
operations or facilities, the escape rate is calculated as the maximum
anticipated flow rate through the system. For a new gas well, the escape rate
is calculated using the maximum open-flow rate of offset wells in the pool or
reservoir, or the pool or reservoir average of maximum open-flow
rates.
(3) For existing oil wells,
the escape rate is calculated by multiplying the producing gas/oil ratio by the
maximum daily production rate or the best estimate of the maximum daily
production rate.
(4) For new oil
wells, the escape rate is calculated by multiplying the producing gas/oil ratio
by the maximum daily production rate of offset wells in the pool or reservoir,
or the pool or reservoir average of the producing gas/oil ratio multiplied by
the maximum daily production rate.
(5) For facilities or operations not
mentioned, the escape rate is calculated using the actual flow of the gaseous
mixture through the system or the best estimate of the actual flow of the
gaseous mixture through the system.
E. "GPA" means the gas processors
association.
F. "LEPC" means the
local emergency planning committee established pursuant to the Emergency
Planning and Community Right-To-Know Act,
42
U.S.C. section 11001.
G. "NACE" means the national association of
corrosion engineers.
H.
"Potentially hazardous volume" means the volume of hydrogen sulfide gas of such
concentration that:
(1) the 100-ppm radius of
exposure includes a public area;
(2) the 500-ppm radius of exposure includes a
public road; or
(3) the 100-ppm
radius of exposure exceeds 3000 feet.
I. "Public area" means a building or
structure that is not associated with the well, facility or operation for which
the radius of exposure is being calculated and that is used as a dwelling,
office, place of business, church, school, hospital or government building, or
a portion of a park, city, town, village or designated school bus stop or other
similar area where members of the public may reasonably be expected to be
present.
J. "Public road" means a
federal, state, municipal or county road or highway.
K. "Radius of exposure" means the radius
constructed with the point of escape as its starting point and its length
calculated using the following Pasquill-Gifford derived equation, or by such
other method as the division may approve:
(1)
for determining the 100-ppm radius of exposure: X = [(1.589)(hydrogen sulfide
concentration)(Q)](0.6258), where "X" is the radius
of exposure in feet, the "hydrogen sulfide concentration" is the decimal
equivalent of the mole or volume fraction of hydrogen sulfide in the gaseous
mixture and "Q" is the escape rate expressed in cubic feet per day (corrected
for standard conditions of 14.73 psi absolute and 60 degrees
fahrenheit);
(2) for determining
the 500-ppm radius of exposure: X = [(0.4546)(hydrogen sulfide
concentration)(Q)](0.6258), where "X" is the radius
of exposure in feet, the "hydrogen sulfide concentration" is the decimal
equivalent of the mole or volume fraction of hydrogen sulfide in the gaseous
mixture and "Q" is the escape rate expressed in cubic feet per day (corrected
for standard conditions of 14.73 psi absolute and 60 degrees
fahrenheit);
(3) for a well being
drilled, completed, recompleted, worked over or serviced in an area where
insufficient data exists to calculate a radius of exposure but where hydrogen
sulfide could reasonably be expected to be present in concentrations in excess
of 100 ppm in the gaseous mixture, a 100-ppm radius of exposure equal to 3000
feet is assumed.
