CUSTODY TRANSFER DATA MANAGEMENT

Transcription

1 AN INTEGRAL APPROACH TO CUSTODY TRANSFER DATA MANAGEMENT Han van Dal Measurement Data: from Well to Awareness

2 STATEMENT With respect to Custody Transfer Data the current generation of Metering Control Systems is dumb inaccurate time-consuming 2

3 CONTENTS What is Custody Transfer Data? What can be improved? Mismeasurement management Relation to system uncertainty Case study Conclusions 3

4 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 4

5 OLD SITUATION Custody Transfer Data = Set of printouts 5

6 CURRENT SITUATION Custody Transfer Data = Set of electronic files 6

7 WHAT CAN BE IMPROVED? Metering Control Systems are made for: Daily operation and not for: Technicians Metering specialists Auditors Accounting staff 7

8 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? 8

9 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? 9

10 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? 10

11 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 11

12 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 12

13 MISMEASUREMENT OVERVIEW CT data trend Historical Meter Ticket Overview.. with Financial Correction Measurement Alarms Measurement Events 13

14 MISMEASUREMENT CORRECTION Best guess for failed input? What was the correct setting? How to recalculate the ticket? How to convince the buyer? 14

15 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 15

16 METER TICKET RECALCULATION 1. BATCH NUMBER 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 hours 6. METER CLOSING READING bbl 7. METER OPENING READING bbl 8. INDICATED VOLUME bbl 9. AVERAGE FLOW RATE bbl/h 10. GROSS VOLUME bbl 11. AVERAGE METER FACTOR OBSERVED RELATIVE DENSITY M 13. OBSERVED TEMPERATURE 0.0 F M 14. RELATIVE DENSITY AT 60 F WEIGHTED AVERAGE TEMPERATURE 94.4 F 16. TEMPERATURE CORRECTION FACTOR (CTLm) WEIGHTED AVERAGE PRESSURE psig 18. PRESSURE CORRECTION FACTOR (CPLm) COMBINED CORRECTION FACTOR (CCFm) NET STD VOL AT 60 F & psia (0 psig) bbls 21. NET STD VOL AT 15 C & kpa (0 kpa (ga)) m3 22. NET WEIGHT long tons 22. NET WEIGHT metric tons 16

17 METER TICKET RECALCULATION bbl 65 API ᵒF 195 psi GSV bbl bbl 65 API ᵒF 205 psi GSV bbl Up to 0.01% difference at stable conditions API MPMS bbl 65 API ᵒF 200 psi GSV bbl 17

18 METER TICKET RECALCULATION Significant difference at highly fluctuating conditions For example Flow computer GSV = bbl API MPMS 12.2 GSV = bbl Up to 0.10% 18

19 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 hours 6. METER CLOSING READING MMSCF 7. METER OPENING READING MMSCF 8. TOTAL VOLUME MMSCF 11. AVERAGE FLOW RATE MMSCFD 12. AVERAGE DIFF PRESSURE inch WC 13. AVERAGE TEMPERATURE F 17. AVERAGE STATIC PRESSURE psig 18. AVERAGE DENSITY 6.45 lb/scf Inaccurate for Gas dp flow meters q (dp x P) FWA dp is useless 19

20 METER TICKET CORRECTION Case : Temperature fails for 35 minutes What is the additional uncertainty of the different correction methods for liquid and gas? 20

21 METER TICKET CORRECTION Basic conventional correction method Optimal conventional correction method 21

22 METER TICKET CORRECTION New API MPMS Ch21 based correction method * Patent pending * 22

23 METER TICKET CORRECTION 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% Relative to corrected quantity that would have been calculated at 1 sec resolution 23

24 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 inaccurate time-consuming smart accurate time-saving 24

25 Smart, accurate and highly automated Metering Control Systems to achieve comprehensive and integral Custody Transfer Data Management THANK YOU FOR YOUR ATTENTION Questions? Measurement Data: from Well to Awareness