ALI AL-QURAINI (Loss Control Engineer)

KOC

ALI AL-QURAINI graduated from Kuwait University-College of Engineering and Petroleum, June 2008 obtaining BS Degree in Chemical Engineering. I have been working in Kuwait Oil Company since December 2008 as Loss Control Engineer in Export Technical Services Team. My experience is in Prover calibration by water draw calibration method and master meter method, assessing the performance of the meters, participated in FATs, SATs and PATs of metering skids and metering supervisory systems. Analysis and verifying vessel calculations.

Obtaining Optimum Accuracy When using Online Master Meter Method

Outline

• What is Master Meter Method Calibration.

• Applicable liquids for M.M.M. Calibration according to

API.

• Bias error that K.O.C. was having in the measurement.

• K.O.C. custody measurement policies.

• Diff between Diesel and Crude as a medium for the

M.M.M. calibration

Outline

• Reasons for the difference in BPV when using different Medium for M.M.M. Calibration.

• The Importance of the Master Meter Accuracy.

What is M.M.M.

• Calibrate the Master Prover by waterdraw.

• Calibrate your Master Meter by Master Prover.

• Calibrate your field prover or field meter by master meter.

Applicable Liquids

• The API MPMS Ch. (4.9.3) mentions several applicable liquids For M.M.M.

• This gives the perception that BPV will not change with different medium used.

• K.O.C. found that different medium will give different BPV.

Bias Error

• The Ship-Shore differences recorded after vessel

loading is almost all the time to the benefit of the ship.

Ship Shore Difference For Berth 21

Figure 1

Berth 21 Meter Skid

• Metering Skid with six streams attached to 36” bidirectional Prover.

• 16” turbine flow meters.

• Skid is connected to flow computers and Supervisory system.

K.O.C. Policies

• RTDs, PTs on streams and provers are verified in quarterly basis.

• Flow meters Proving done in shipment basis.

• Prover calibration is done in annual basis.

K.O.C. Policies

• Flow meter proving acceptance criteria:

• A repeatability of 0.04% over 5 proving runs.

• The new meter factor within ± 2std of last 25 proves.

• The new meter factor within ± 0.15% from the initial meter factor.

K.O.C. Policies • Average flow waited meter factor for the

shipment(curve) is applied.

• Curve generation for each flow meter.

i. Six DIFF flow rates and six DIFF TEMP

ranges.

ii. Each curve should meet repeatability and

linearity criteria.

Berth 21 Diesel V.S KEC as Medium • K.O.C reviewed the BPV History.

33760

33762

33764

33766

33768

33770

33772

33774

33776

33778

Withdraw Diesel Diesel KEC KEC KEC

The importance of BPV in volumetric dynamics calculations:

• Recalculate BPV assuming Crude Oil as Medium.

• Different prover calibration medium will give different BPV.

GSTDM = IV * MF * CTLm * CPLm

Todays Ship Shore Differnce Behavior:

Master Meter Accuracy

• The performance of the M.M.

remain Unchanged

• Master Meter should show a

good repeatability and

reproducibility

• From this study , K.O.C conclude that M.M prover

calibration will be more representable when it is done

“online” and using a process liquid.

conclusion

Where To Get More Information

• API MPMS Ch. (4.9.3), Determination of the Volume of Displacement provers by the Master Meter Method of Calibration.

• API MPMS Ch (11.1), Temperature and Pressure Volume Correction Factors

• API MPMS Ch (12.2), Calculation of Petroleum Quantities Using Dynamic Measurement

• ASTM D 1250-80 Generalized Products, Correction of Volume to 60 F against API Gravity at 60 F

• ASTM D 1250-80 Generalized Crude Oil Correction of Volume to 60 F against API Gravity at 60 F

• API MPMS Ch (4.7), Field Standard Test Measure 1998

Thank You