CUSTODY TRANSFER DATA MANAGEMENT
Transcript of CUSTODY TRANSFER DATA MANAGEMENT
Measurement Data: from Well to Awareness www.SpiritIT.com
CUSTODY TRANSFER DATA MANAGEMENT
Han van Dal
AN INTEGRAL APPROACH TO
STATEMENT
With respect to Custody Transfer Data the current generation of Metering Control Systems is
• dumb
• inaccurate
• time-consuming
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CONTENTS
What is Custody Transfer Data?
What can be improved?
Mismeasurement management
Relation to system uncertainty
Case study
Conclusions
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CUSTODY TRANSFER DATA
API MPMS 21.1 (Gas) & 21.2 (Liquid)
• Quantity Transaction Records
• Configuration Logs
• HW & SW Versions
• Event Logs
• Field Test Reports
• Corrections with their reason
Why?
To verify correctness of data
To allow for correction of failures
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OLD SITUATION Custody Transfer Data = Set of printouts
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CURRENT SITUATION Custody Transfer Data = Set of electronic files
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WHAT CAN BE IMPROVED?
Metering Control Systems are made for:
Daily operation
… and not for:
Technicians
Metering specialists
Auditors
Accounting staff
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PURPOSE #1: CORRECTNESS OF DATA
Are all settings correct?
Any changes in settings, SW or HW?
Calibrations performed in time?
Any maintenance applied?
Have measurement failures occurred?
Have tickets been corrected?
If so, how and why?
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PURPOSE #2: CORRECTION OF FAILURES
How big is the error (financial value)?
Is correction worth the trouble?
What is the best guess for the failed input?
How to accurately recalculate the ticket?
How to convince the Buyer?
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WHAT ELSE CAN BE IMPROVED?
Is the overall system accuracy within spec?
Why wasn’t the frozen value detected earlier?
How is my meter doing?
Is any transmitter drifting?
What’s the density of water in all flowcomps?
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INTEGRAL CT DATA MANAGEMENT
Relational data (meter tickets & audit trail)
IT (data storage, cyber-security, integrity)
Configuration management (FC, EFM)
Mismeasurement management
• Detection
• Overview
• Correction
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MISMEASUREMENT DETECTION Flow computer alarms
But also:
Flow meter diagnostics
Smart transmitter diagnostics
QMI diagnostics
On-line data validation
On-line logical checks
Control Charts
CUSUM Charts
-1.5
-1
-0.5
0
0.5
1
1.5
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MISMEASUREMENT OVERVIEW
CT data trend
Historical Meter Ticket Overview
.. with Financial Correction
Measurement Alarms
Measurement Events
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MISMEASUREMENT CORRECTION
Best guess for failed input?
What was the correct setting?
How to recalculate the ticket?
How to convince the buyer?
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SYSTEM UNCERTAINTY
Metering equipment
Proving
Sampling
Laboratory analysis
Flow computers
Meter ticket recalculation
• API MPMS 12.2
• Proving (Meter factor)
• Sampling (density, BS&W)
Meter ticket correction
• Equipment failures
• Faulty data entries
• Failed field calibrations
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METER TICKET RECALCULATION 1. BATCH NUMBER 050511
2. TYPE OF LIQUID NG
3. METER CLOSING READING (DATE/TIME) 05/06/11 00:00
4. METER OPENING READING (DATE/TIME) 05/05/11 00:00
5. NET DELIVERY TIME 24.001 hours
6. METER CLOSING READING 23208593 bbl
7. METER OPENING READING 23167330 bbl
8. INDICATED VOLUME 41263 bbl
9. AVERAGE FLOW RATE 1705.4 bbl/h
10. GROSS VOLUME 41258.87 bbl
11. AVERAGE METER FACTOR 1.0001
12. OBSERVED RELATIVE DENSITY 0.0000 M
13. OBSERVED TEMPERATURE 0.0 °F M
14. RELATIVE DENSITY AT 60°F 0.6646
15. WEIGHTED AVERAGE TEMPERATURE 94.4 °F
16. TEMPERATURE CORRECTION FACTOR (CTLm) 0.9732
17. WEIGHTED AVERAGE PRESSURE 317.6 psig
18. PRESSURE CORRECTION FACTOR (CPLm) 1.0044
19. COMBINED CORRECTION FACTOR (CCFm) 0.9775
20. NET STD VOL AT 60°F & 14.696 psia (0 psig) 40355.30 bbls
21. NET STD VOL AT 15°C & 101.325 kPa (0 kPa (ga)) 6410.843 m3
22. NET WEIGHT 4185.52 long tons
22. NET WEIGHT 4252.70 metric tons
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METER TICKET RECALCULATION
Up to 0.01% difference at stable conditions
100000 bbl 65 API60
75 ᵒF 195 psi
GSV 99180 bbl
100000 bbl 65 API60
76 ᵒF 205 psi
GSV 99120 bbl
API MPMS 12.2 200000 bbl
65 API60
75.5 ᵒF 200 psi
GSV 198320 bbl
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METER TICKET RECALCULATION
Significant difference at highly
fluctuating conditions
For example
Flow computer
GSV = 37942 bbl
API MPMS 12.2
GSV = 37978 bbl
Up to 0.10%
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METER TICKET RECALCULATION 1. METER CLOSING READING (DATE/TIME) 05/06/11 00:00
2. METER OPENING READING (DATE/TIME) 05/05/11 00:00
3. NET DELIVERY TIME 24.001 hours
6. METER CLOSING READING 23388.593 MMSCF
7. METER OPENING READING 23167.330 MMSCF
8. TOTAL VOLUME 221.263 MMSCF
11. AVERAGE FLOW RATE 221.012 MMSCFD
12. AVERAGE DIFF PRESSURE 23.12 inch WC
13. AVERAGE TEMPERATURE 113.3 °F
17. AVERAGE STATIC PRESSURE 1317.6 psig
18. AVERAGE DENSITY 6.45 lb/SCF
Inaccurate for
Gas
dP flow meters
q ≈ √(dP x P) FWA dP is useless
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METER TICKET CORRECTION
Case : Temperature fails for 35 minutes
What is the additional uncertainty of the different correction methods for liquid and gas ?
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METER TICKET CORRECTION Basic conventional correction method
Optimal conventional correction method
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METER TICKET CORRECTION New API MPMS Ch21 based correction method
* Patent pending *
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METER TICKET CORRECTION
Relative to corrected quantity that would have been calculated at 1 sec resolution
Correction Liquid
Turbine
Steady
Liquid
Turbine
Fluctuating
Gas
Orifice
FWA dP
Gas
Orifice
TWA √dPxP
Basic correction 0.06% 0.83% 3.22% 0.30%
Optimal correction 0.02% 0.14% 3.22% 0.22%
API 21 based cor. 0.00% 0.00% 0.00% 0.00%
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CONCLUSIONS Accurate correction is currently NOT possible for many applications
New API 21 method is accurate for all meter types, liquid and gas
Automation of Mismeasurement Management
• makes systems smart
• saves time and resources
• avoids disputes with buyer
dumb smart
inaccurate accurate
time-consuming time-saving
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Measurement Data: from Well to Awareness www.SpiritIT.com
THANK YOU FOR YOUR ATTENTION Questions?
Smart, accurate and highly automated
Metering Control Systems
to achieve comprehensive and integral
Custody Transfer Data
Management