Southern Natural Gas Company
Seventh Revised Volume No. 1
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Effective Date: 05/05/2008, Docket: RP04- 42-003, Status: Effective
Fourth Revised Sheet No. 108 Fourth Revised Sheet No. 108 : Effective
Superseding: Third Revised Sheet No. 108
GENERAL TERMS AND CONDITIONS
(Continued)
Section 3.1 (continued)
(g) have a cricondentherm hydrocarbon dew point temperature ("HDP") equal
to or less than the specification posted on SoNet Premier as a "Hydrocarbon Dew
Point Limitation" as it becomes necessary from time to time to prevent hydrocarbon
condensation in COMPANY's system or from deliveries to its customers in order to
ensure that the gas redelivered will be merchantable as provided in Section 3.2
below. COMPANY will use certain monitoring points downstream of major gas supply
sources on its system ("Monitoring Points") to measure the quantity of equivalent
gallons of liquid per mcf of gas of Hexanes and heavier (C6+) hydrocarbons in the
gas stream ("GPM Factor"). The Monitoring Points will be located at COMPANY'S
Enterprise Compressor Station on its South Main Line, the Rome No. 1 Meter Station
on COMPANY'S facilities and those of Southern LNG Inc. in Chatham County, Georgia.
The HDP calculations will be performed using the Peng Robinson equations of state.
The Hexane plus values used in the HDP calculation will be verified on an annual
basis using an extended analysis from samples taken at the Monitoring Points.
COMPANY will use the actual GPM Factor at the Monitoring Points or a projected GPM
Factor based on confirmed or reasonably anticipated events, e.g., a processing plant
outage, in order to determine (i) whether a limitation is necessary, and (ii) what
portion of COMPANY's system is affected by an excessive GPM Factor. COMPANY shall
then determine the GPM Factor level that is necessary to ensure that liquefiable
hydrocarbons do not condense out of the gas stream ("GPM Target"). The GPM Target
will then be correlated to an HDP specification which will be included in the
posting ("HDP Specification"). COMPANY shall establish groups of two or more meter
stations that will be sampled at a common point in order to determine whether they
meet the HDP Specification in the aggregate ("Aggregation Group"). All of the
processing plants located on COMPANY's system near Toca, Louisiana, shall be
referred to herein as the "Toca Plant." All of the Receipt Points located upstream
of the Toca Plant shall constitute one such Aggregation Group. The gas supplies from
the Receipt Points in such Aggregation Group will be sampled immediately downstream
of the Toca Plant at a point before the first Receipt Point on COMPANY's facilities
downstream of the Toca Plant. Other Aggregation Groups as established from time-to-
time shall be posted on SoNet Premier. New Receipt Points will be automatically
assigned to the existing Aggregation Group covering the geographical area where the
point is located. COMPANY shall provide thirty (30) days notice with a posting on
SoNet Premier to move a Receipt Point from one Aggregation Group to another and
shall include in said posting the operational reasons for moving the Receipt Point.
COMPANY shall attempt to minimize the use of HDP Limitation Notices and to the
greatest degree possible, shall endeavor to implement the highest HDP for specific
portions of its pipeline system as necessary to prevent hydrocarbon condensation
based on operating conditions, and shall limit the duration of the HDP Limitation
Notice to the extent possible. In assessing system operating conditions, COMPANY
shall consider all relevant factors affecting hydrocarbon condensation, including
specifically (i) the HDP at the Monitoring Point, (ii) events that could lead to
hydrocarbon condensation, (iii) market demand (location and volume), (iv) supply
diversity (location and volume), (v) the weather, and (vi) any opportunities within
Southern's control to blend gas supplies. COMPANY will include in any posting
pursuant to this section (1) the anticipated duration of the limitation; (2) the
Receipt Point(s) and Aggregation Group(s) with their associated Receipt Point(s) on
the system subject to the limitation; (3) the effective date and time by which
parties have to conform to the limitation;(4) the latest available HDP at the
Monitoring Points, all Aggregation Group(s) upstream of the affected Monitoring
Point, all pipeline interconnections upstream of the affected Monitoring Point, and
all Receipt Point(s) that have an HDP above the HDP Specification within the
Aggregation Group(s) that has/have an HDP above the HDP Specification; and (5) the
reason for the limitation, including the information utilized in deciding to issue
the HDP Limitation Notice. Receipt Points delivering gas into COMPANY's system
directly from well head production facilities where the actual flow during the
calendar month immediately preceding the month in which the limitation notice is
posted averaged 500 dth/d or less will be exempt from the limitation in any such
posting. COMPANY will provide prior notice by posting the limitation at least two
(2) days before the limitation will be effective. COMPANY will attempt to provide
this notice prior to the beginning of the month in which the limitation is to be
effective, but if such prior notice is not practicable, COMPANY will explain the
reason in the posting why it was unable to give such notice prior to the beginning
of the month. COMPANY shall accept gas entering the system at all Receipt Points and