Clay Basin Calculations(Estimates)


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Firm Injection Withdrawal Allocation Calculation

The injection and withdrawal definition can be found in Part 2 Section 9.2 of Questar's Tariff.
MRD = Annual Working Gas / 150 days * .80 or 120

Annual Working Gas (dth)

Sum of Annual Working Gas volumes (dth)*
* excludes QPC's firm balancing account WG volumes

Firm Injection Allocation = (X/Y)*Z

X= Firm Shipper's annual working gas(dth)  X Injection Allocation:  dth/day
Y= Sum of Annual working gas of all firm shippers(dth)  Y    
z= Available injection capacity(dth)  Z    
Note: Injection capacity can range anywhere from 250,000 dth/day to 360,000 dth/day.
Daily injection capacity can be found on QPC's web site under daily storage capacity.

Firm Withdrawal Allocation = [(A/B) * (C-D)] + E

A = Individual FSS working gas remaining in storage(dth)    Firm Withdrawal Allocation: dth/day
B = Total working gas remaining in storage for all FSS(dth) Shippers  B    
C = Maximum possible reservoir deliverability attributable to the sum of cushion and FSS shipper's working gas inventory(dth)  C    
D= Sum of FSS shippers minimum required deliverabilities (dth)  D    
E= FSS shipper's required minimum deliverability(dth)  E MRD:  dth/day
Minimum Required Deliverability , as defined in the tariff, is equal to :
The minimum withdrawal rate or quantity of gas that firm shipper may withdraw on a firm basis each day up to and including the last day of the withdrawal period, subject to shipper having working gas remaining in storage. It shall be determined by dividing shipper's annual working gas by the product of 150 days and the decimal equivalent of an 80% load factor. Thus:

Disclaimer: Worksheet and calculations to be used solely for the purpose of estimating firm injection and withdrawal allocation capacities. Please contact QPC marketing and scheduling for actual numbers.

For interruptible withdrawal amount, please refer to the tariff Part 3 Section 10.2 b.

Clay Basin Calculations(Estimates)