Intraday Shipper Allocations Customer Operations

Transcription

1 Customer Operations, BC Pipeline and Field Services Customer Operations Prepared by: Gas Accounting Revision Tracking Date Created 09/01/2007 Last Updated 03/25/2015 Document No Revision 41

2 Table of Contents Overview 2 12 Intraday Schedule 2 13 RGT Shipper Allocation Raw Gas Determination at a PS 3 14 Theoretical Residue Gas Volume and Energy Theoretical H 2 S and Acid 4 15 Shrinkage, Conversion, Factors at PS Calculation of Conversion Factors 5 16 Plant Outlet Balancing Plant Outlet Balancing Calculations 6 17 Outlet Allocation for Ft Nelson Area 6 18 Dry Gas Shipper Allocation Energy Determination at Shipper/Upstream Supplier Volume Determination after DOP Process Complete 7-1-

3 1 11 Overview The Intraday Shipper Allocation process occurs during the Gas Day and is based on the daily intraday information There are currently three cycles: 1 Predicted; 2 Estimated; and 3 Final Estimate The three cycles are required to reflect whether the process occurs for the current Gas Day (Predicted), for yesterday s Gas Day (Estimated) or 6 hours after the Gas Day is completed The Shipper Allocation process is used to determine the amount of raw gas volume, residue gas (volume and energy), H 2 S, Acid volume, propane, butane and pentane volumes associated with a Shipper at a Production Source (PS) on a daily basis, with results dependent on the gathering system The Intraday Shipper Allocation process is run for both raw gas and dry gas gathering systems The actual Shipper Allocation process for the two gathering systems, however, is defined separately, as the results are different 12 Intraday Schedule The Intraday Shipper Allocation will be run on a scheduled basis throughout the Gas Day The scheduled times are given below in Central Clock Time (CCT) and are displayed as the start time for the Intraday Shipper Allocation process Typical process completion time for the Shipper Allocation is 30 minutes Intraday Shipper Allocation runs are defined as follows: Predicted schedule - the is run for the current Gas Day using predicted Receipt Point (RP) values and PS estimates Estimated schedule - the Intraday Shipper Allocation is run for yesterday's Gas Day based on RP values and PS estimates Final Estimated schedule - the final Intraday Shipper Allocation is run 6 hours after the Gas Day is complete No more changes can be made to PS estimates The following table displays the Field Services and Pipeline Intraday Shipper Allocation schedule: Predicted Estimated Final Estimate 11:00 10:15 15:00 12:00 11:15 13:00 12:15 14:00 13:15 15:10 16:00-2-

4 Predicted Estimated Final Estimate 17:00 18:00 22:00 02:00 04:30 05:30 08:00 13 RGT Shipper Allocation The Predicted, Estimated and Final occur during the Gas Day and are run as per the schedule in Section 12 For each PS that a Shipper nominates to, a theoretical amount of raw gas volume, residue volume, residue energy, H 2 S and Acid will be determined 131 Raw Gas Determination at a PS The raw gas volume at a PS is determined by prorating the raw gas volume at an RP to each PS The raw gas volume at an RP can be predicted, estimated or a final estimate Predicted RP volumes, with EFM and communications will be determined as follows by using any known accumulated raw gas volume and the last reported volume flow rate to extrapolate the 24 hour raw gas volume total RP volumes with chart measurements will be based on the sum of the PS raw gas volumes reported by the RPO Once the raw gas volume is determined at an RP, it will be prorated back to each PS based on the PS raw gas volumes, as follows: ARGV ps1 = (RGV ps1 / TOTV rp ) V rp TOTV rp Where: ARGV ps1 = allocated raw gas volume for PS1 (10 3 m 3 ) V rp = raw gas volume for an RP (10 3 m 3 ) TOTV rp = sum of PS raw gas volumes at an RP (10 3 m 3 ) RGV ps1 = raw gas volume for PS1 (10 3 m 3 ) RGV ps2 = raw gas volume for PS2 (10 3 m 3 ) RGV psn = raw gas volume for PSn (10 3 m 3 ) 14 Theoretical Residue Gas Volume and Energy The theoretical residue gas volume is determined by multiplying the theoretical PS raw gas volume by the RAW to RES conversion factor, as follows: -3-

5 RESEN ps1 = ARGV ps1 * RAWRES ps1 Where: ARGV ps1 = allocated PS raw gas volume for PS1 (10 3 m 3 ) RAWRES ps1 = the raw gas volume to residue gas volume conversion factor for PS1 Similarly, the theoretical residue gas energy is determined by multiplying the theoretical PS residue volume by the PS fixed heating value, as follows: RESEN ps1 = RESVOL ps1 * MJF ps1 Where: RESVOL ps1 = allocated residue volume at PS 1 (10 3 m 3 ) RESEN ps1 = allocated residue energy at PS1 (GJ) ARGV ps1 = allocated PS raw gas volume for PS1 (10 3 m 3 ) RAWRES ps1 = the raw gas volume to residue gas volume conversion factor for PS1 MJF ps1 = megajoule factor for PS1 (MJ/m 3 ) 141 Theoretical H 2 S and Acid The amount of H 2 S and Acid Gas allocated to a PS will be based on the allocated PS residue volume and the applicable conversion factor The equation to determine the amount of theoretical H 2 S at a PS on a daily basis is as follows: H2S ps1 = RESVOL ps1 * H2SCF ps1 Where: H2S ps1 = H 2 S allocated to PS1 for day 1 (10 3 m 3 ) RESVOL ps1 = res gas volume to PS1 for day 1 (10 3 m 3 ) H2SCF ps1 = the daily res to H 2 S conversion factor for PS1 The equation to determine the amount of Acid Gas to allocate to PS1 on day one is: ACID ps1 = ARGV ps1 * ACIDCF ps1 Where: ACID ps1 = Acid allocated to PS1 for day 1 (10 3 m 3 ) ARGV ps1 = raw gas volume to PS1 for day 1 (10 3 m 3 ) ACIDCF ps1 = the daily res to Acid conversion factor for PS1 15 Shrinkage, Conversion, Factors at PS For each PS that has a fixed representative analysis, a conversion factor is calculated on a monthly basis The conversion factors are provided to Shippers and RPOs via Spectra s web based Customer Interface (CI) on the Monthly Conversion Factors report This report will provide factors for the following: Raw to Res; Res to Raw; Res to Acid; Res to H 2 S (Sulfur); Res to C3; -4-

6 Res to C4; Res to C5; and Megajoule Factor 151 Calculation of Conversion Factors The conversion factors for each PS in a gathering system are determined based on the following process: Calculate the conversion factors based on the allocation results displayed on the Plant Allocation Report This calculation is only used if the Plant Allocation has been approved and raw gas volume, residue gas volume, residue gas energy, theoretical acid, theoretical H 2 S, propane, butane and pentane has been allocated to the PS The calculation uses actual results from the Plant Allocation If no allocated results at the PS are available, conversion factors will be based on the formulas defined below: Raw to Residue: RAWRES ps1 = 1 - (H 2 S +CO 2 + ic 4 + nc 4 + ic 5 + nc 5 + C 6 + C 7 + ) ps1 (FUELFACT ps1) FUELFACT ps1 = (H 2 S +CO 2 + C 3 + ic 4 + nc 4 + ic 5 + nc 5 + C 6 + C 7 + ) ps1 * Plant Fuel Factor The Plant Fuel Factor is based on the yearly average of plant fuel to fuel usage Ratio (ie, acid gas volume) This factor is updated on a yearly basis in the Plant Factor table in GMS The current plant fuel factors used for the purpose of estimating PS conversion factors which cannot be generated from a previously approved Plant Allocation are as follows: McMahon - 038; Aitken Creek 038 Ft Nelson - 038; Pine River - 013; and Sikanni Residue to Raw: RESRAW ps1 = 1 / (RAWRES ps1 ) Residue to Acid: RESACID ps1 = (RESRAW ps1 ) * (H 2 S +CO 2 ) ps1 Residue to H 2 S: RESH2S ps1 = (RESRAW ps1 ) * (H 2 S) ps1 Residue to C3: RESC3 ps1 = (RESRAW ps1 ) * (C 3 ) ps1 Residue to C4: -5-

7 RESC4 ps1 = (RESRAW ps1 ) * (ic 4 + nc 4 ) ps1 Residue to C5: RESC5 ps1 = (RESRAW ps1 ) * (ic 5 + nc 5 + C 6 + C 7 + ) ps1 Megajoule Factor: MJF ps1 = [(C 1 x HVC 1 ) ps1 + (C 2 x HVC 2 ) ps1 + (C 3 x HVC 3 ) ps1] / (C 1 + C 2 + C 3 + N 2 ) ps1 Note: Components are in Mole Fractions 16 Plant Outlet Balancing Plant Outlet Balancing (POB) is part of the Intraday Shipper Allocation process and occurs after the production source estimates have been calculated The applicable plant s PS estimated residue gas volumes (10 3 m 3 ) and (GJs) will then be totaled for the respective day Daily measured plant volumes and energy are then forced balanced to the PS estimates 161 Plant Outlet Balancing Calculations The Plant Outlet Factor for 10 3 m 3 pro-ration is determined by dividing the total daily Plant Outlet residue meter volume 10 3 m 3 by the total theoretical residue 10 3 m 3 from PS estimates at each plant A similar calculation is used in respect to energy (GJs) The equation that follows will determine the POB factors PF = TOTAL PLANT OUTLET / TOTALTHEORES PF = Plant Factor TOTALTHEORES = total residue volume (10 3 m 3 or GJ) of PS estimates for plant TOTAL PLANT OUTLET = total daily plant outlet measurement (10 3 m 3 or GJ) 17 Outlet Allocation for Ft Nelson Area In the Ft Nelson Area a further step takes place after the POB The estimated total residue volume and energy determined for each shipper are allocated to either or to both T-North on the Spectra system or to Komie East on the TCPL system The residue gas will be allocated to the Ft Nelson North Plant by the following steps: 1) Allocate Primary 2) Allocate Secondary 3) Allocate IT 4) Allocate Swing 5) Allocate to Ft Nelson North Plant Contract Holders 6) Allocate to Physical Shippers 7) Allocate to All Shippers The allocation to the Ft Nelson Gas Plant (T-North) will be the difference between the allocated shipper totals and the amount allocated to the Ft Nelson North Plant -6-

8 18 Dry Gas Shipper Allocation The Dry Gas Shipper Allocation occurs during the Gas Day and is run as per the Intraday Shipper Allocation schedule outlined in section 42 For each Shipper/Upstream Supplier (SUS) that a shipper nominates to, an amount of residue gas volume and residue energy is determined 181 Energy Determination at Shipper/Upstream Supplier The energy at a SUS will be determined by prorating the energy at an RP to each SUS The energy at an RP is estimated based on the following rules: 1 Dry Gas Receipt Point with EFM and Communications - the energy is based on the volume multiplied by the last known heating value (megajoule factor) provided by the EFM device 2 Dry Gas Receipt Point with Chart - the energy is based on the sum of the SUS energy (SUS Estimates for current Gas Day) reported by the RPO Once the energy is determined at a Receipt Point, it will be prorated back to each SUS as follows: AEN sus1 = (EN sus1 / TOTEN rp ) * EN rp Where: AEN sus1 = allocated energy for SUS1 (GJ) EN rp = energy for a RP (GJ) TOTEN rp = EN sus1 = EN sus2 = EN susn = sum of estimated SUS energy at a RP (GJ) energy for SUS1 (GJ) energy for SUS2 (GJ) energy for SUSn (GJ) 182 Volume Determination after DOP Process Complete The allocated volume for a shipper at a SUS is determined after the allocated energy is determined for the shipper The allocated volume is calculated by dividing the allocated energy by the RP heating value -7-

9 Reviewers Name Melanie McDonald Position/Department Business Analyst and Documentation Specialist Approvals Name Position/Department Signature Mel Thorp Director Gas Accounting Revision History Date Author Revision Revision Comments 05/28/2007 Melanie Bird 301 Template Conversion 06/11/2007 Mandy Grad 302 Information Check and Update 09/16/2009 Melanie McDonald 40 Updated 03/17/2015 Tim Bowes 41 Information Check and Update 03/25/2015 Joycelyn Creed 41 Updated template Related Documents Document Title Document Reference -8-