Truck Unloading Air Eliminators

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2 PURPOSE The purpose of an air eliminator is to remove the gas or air bubbles entrained in the fluid being pumped off the truck. Removing the bubbles, or void fraction, improves the accuracy and performance of the meter. When the fluid density is used to calculate the water cut (Net Oil Calculation), removing the void fraction increases the fluid density, which will increase the calculated water cut.

3 Truck Unloading Air Eliminators Void Fraction The percentage or volume of product in a meter that is composed of gas or air bubbles. 8.2% Void Fraction

4 Truck Unloading Air Eliminators Void Fraction The effect on void fraction in a PD or turbine meter is obvious, an 8.2% void fraction would cause the meter to read 8.2% higher than the actual fluid volume. The gas or air simply takes up the space in the meter. 8.2% Void Fraction

5 Truck Unloading Air Eliminators Sources of Void Fraction Fluid being measured at or near bubble point. Introduction of air into the fluid, i.e. the truck pump. At the start of a load, hoses empty. Switching tanks or compartments. The end of a load.

6 Truck Unloading Air Eliminators Void Fraction The effect of void fraction in a Coriolis Meter. Causes the drive coil input to increase shock absorber effect. Reduces the measured density of the fluid. Some newer coriolis meters can accurately measure the mass of the fluid at significant void fraction levels.

7 Truck Unloading Air Eliminators Ways to Reduce Void Fraction Increase back pressure on system to prevent flashing. Increase back pressure to reduce the bubble size. Increase pumping pressure to reduce the amount of air the truck pump can move through the meter. Install an air eliminator to remove the gas and air from the fluid.

8 Truck Unloading Air Eliminators Effect of Void Fraction on Density Measurement Reduces the measured Density Example: Water Density = 5 kg/m3 5% Void Fraction in Fluid Indicated Density = (5 x.95) + (.2 x.5) = = 92.6 kg/m3

9 Truck Unloading Air Eliminators Net Oil Calculation (NOC) Calculates Water percentage based on fluid densities Water % = (Fluid Density Oil Density) x (Water Density Oil Density) Ex: Oil 83 kg/m3 Water-5 kg/m3 Fluid 935 kg/m3 Water % = (935 83) x (5 83) = 32.8%

10 Truck Unloading Air Eliminators Effect of 5% Void Fraction Net Oil Calculation (NOC) Ex: Oil 83 kg/m3 Water-5 kg/m3 Fluid 92.6 kg/m3 Water % = ( ) x = 82.% (5 83) What you pay for = 7.9% Oil! Reality = % Water!

11 Truck Unloading Air Eliminators Effect of 25% Void Fraction Net Oil Calculation (NOC) Ex: Oil 83 kg/m3 Water-5 kg/m3 Fluid kg/m3 Water % = ( ) x =.25% (5 83) What you pay for = 89.75% Oil! Reality = % Water!

12 Truck Unloading Air Eliminators Case # - A Tale of Two Meters Identical parallel meter runs M. M. D Body c/w 9739 transmitters One meter run with a Pro-Kut Air Eliminator and back pressure valve, and the other parallel meter run with no air eliminator or back pressure valve.

13 Density gm/cc Flow Rate m3/min Truck Unloading Air Eliminators.4.2 Without Air Eliminator East Riser Load - % Water for Full Load No data from meter at end of load. % water at sample point for entire load. Slug flow for 58 seconds, water air mix, but no fluid measurement Second interval Density gm/cc Flow Rate m3/min Time in Seconds

14 Density gm/cc Flow Rate m3/min. Truck Unloading Air Eliminators.4.2 Without Air Eliminator East Riser Load 2 - Emulsion Full Load Tank Switch Recorded flow very erratic or at zero Density Flow Rate Time seconds

15 Density gm/cc Flow Rate m3/min Truck Unloading Air Eliminators.4 Without Air Eliminator East Riser Load 2 Emulsion at Tank Switch.4.2 Minute 4 second tank Switch.2 Gaps in data during sensor fail and slug flow Density gm/cc Flow Rate m3/min Time Seconds

16 Density gm/cc Flow Rate m3/min Truck Unloading Air Eliminators.9.8 With Air Eliminator West Riset Load - End of Condensate Load No change in density - no air in fluid during unload Density gm/cc Flow Rate m3/min Time Seconds

17 Truck Unloading Air Eliminators.4 With Air Eliminator West Riser - Emulsion Load 2.4 D e n s i t y.2.8 Tank Switch Increasing oil percentage.2.8 F l o w R a t e g m / c c.6.4 Density gm/cc Flow Rate m3/min.6.4 m 3 / m i n Time - Seconds

18 .2 With Air Eliminator Truck Unloading Air Eliminators Density very Stable West Riser - Load 3 Emulsion Density dropped for only 6 seconds at end of tank switch.2 D e n s i t y m 3 / m i n F l o w R a t e m 3 / m i n.2 Density gm/cc Tank Switches.2 Flow Rate m3/min

19 Density gm/cc Flow Rate m3/minute Truck Unloading Air Eliminators.2 With A.E. West Riser - Full Emulsion Load 3 At Tank Switch.2 6 second low density interval Density gm/cc.2 Flow Rate m3/min.2 2 minute tank switch interval Time Seconds

20 Truck Unloading Air Eliminators Case #2 Same Meter Run First slide inline horizontal air eliminator Second slide same meter run with Pro-Kut Air Eliminator M. M. 3 Elite with 27 Transmitter

21 Density kg/m3 Flow Rate M3/hr Truck Unloading Air Eliminators With Low Capacity in line Air Eliminator Riser #2 Flow Pattern with 3" In Line Horizontal Air Eliminator Flow pattern from the meter in 2 second intervals during the switch from the back to the lead trailer. Gaps in lines indicates slug flow and sensor failure due to entrained gas from truck pump. Air eliminator was cycling and dumping Density Flow rate Time Seconds

22 Density kg/m3 Flow Rate m3/hr Truck Unloading Air Eliminators Riser #2 Flow pattern with 3" Pro-Kut Air Eliminator With Pro-Kut Air Eliminator Flow pattern with vertical air eliminator during tank switch on back and lead tanks and end of load Density kg/m3 Flow Rate m3/hr Tme Seconds

23 Truck Unloading Air Eliminators Case #3 Same Meter Run First slide No air eliminator Second and third slide same meter run with Pro-Kut Air Eliminator Same truck and driver for both situations First load is meter run with no air eliminator % water Second load is same meter run with Pro-Kut Air Eliminator with small amount of oil at the top of each tank M. M. 3 D body with 9739 Transmitter

24 Density kg/m3 Flow Rate m3/hr Truck Unloading Air Eliminators Battery Truck Unload Meter Flow Pattern - No Air Eliminator Density kg/m3 Flow Rate m3/hr Tank Switch Time Seconds

25 Density kg/m3 Flow Rate m3/min Truck Unloading Air Eliminators Battery Emulsion Load with Pro-Kut Air Eliminator - Oil At end of Truck Tank Volumes Tank Switch Density kg/m3 Flow Rate m3/hr Time 8 Seconds 2 4 -

26 Density kg/m3 Flow Rate m3/hr Truck Unloading Air Eliminators 2 With Air Eliminator Battery Emulsion Load at Tank Switch Density dropping as oil at the top of the truck tank starts to enter meter Density kg/m3 Tank Switch Flow Rate m3/hr Time Seconds