1. Product Interface Detection in batched multi-product liquid metering
J.L. “Larry Taylor, III
ISA MEMBER
OMNTEC – Innovative Sensor Solutions
ISA (D) Expo 2005
Delhi, India
2 – 4 December 2005

2. Multi-Product Interface Detection
The Challenge
Conventional Approach
The Solution
The Future

3. Multi-Product Interface Detection:
THE CHALLENGE

4. Transmix Minimization
(SLOP)
TRANSMIX B B

5. FUEL: A Vicious Cycle PRODUCT PIPELINE $ $ $ $ CRUDE PIPELINE REFINERY
TRANSMIX
PIPELINE TERMINAL
BUTANE
MARKETING TERMINAL
AVGAS
93 OCTANE
PRODUCT PIPELINE
91 OCTANE
87 OCTANE
JET-A
HS DIESEL
LS DIESEL
FUEL OIL

6. The Challenge
REDUCE TRANSMIX
IMPROVE PURITY

7. How many slop tanks do you have?
THE CHALLENGE
How many slop tanks do you have?
How much loss in revenue does that represent?

8. Conventional Approach
Use densitometer to identify interface
Move densitometer upstream

9. Shortcomings of Densitometers for interface detection
Inadequate compositional resolution to detect product interfaces
Too slow
Too expensive to install very high resolution densitometers upstream of tank manifolds

10. THE SOLUTION
FuelCheck®

11. FuelCheck® Overview
FuelCheck® is a totally fiberoptic petroleum pipeline interface detector which uses index of refraction to differentiate between adjacent batches of refined products

12. FuelCheck® Controller
FuelCheck® System
length up to 2 km
Analog out to SCADA
fiberoptic
interconnect
FuelCheck® Controller
FuelCheck® Probe
Conduit j-box
pipeline
FuelCheck®
sensor

13. Fuel Check Operating Principle
1. Sensor is a 5 mm diameter sapphire hemisphere.
reflected
light
refracted
2. Optical fibers are very precisely fused onto the flat side of the lens.
3. An LED is used to provide constant intensity light to the lens through either of the fibers. (LED located in the FuelCheck Controller, up to 2 km away from sensor)
5 mm
4. The inner surface of the lens acts as a mirror: some of the light reflects inside the lens; however, some light refracts out of the lens into whatever fluid is wetting the lens. The amount of light lost to refraction is directly proportional to the refractive index of the fluid wetting the lens.
5. Whatever light is not lost to refraction returns to the FuelCheck Controller via the other fiber where its intensity is precisely measured and converted to a scaled value.
fiberoptic length
up to 2 km

14. FuelCheck® Probe FEATURES
Completely fiberoptic sensor can be located up to 2 km from controller
Installs into pipeline through 1” (or larger) valve
BENEFITS
No power or wiring required
Remote sensors can be cheaply and easily installed upstream of control manifolds
No pipe fitting or special plumbing required
Immune to EMR and lightning
Inherently safe
conduit J-box
flexible armor
probe body
process insertion fitting
insertion tool adapter
pipeline access valve
(>= 1” full-opening)
threadolet (>=2”)

15. FuelCheck® Response

16. Tandem Sensor Technique
valve
response
time
DIESEL
FuelCheck®
Probe B
fiberoptic
interconnect
(<= 2 km)
FuelCheck®
Probe A
minutes M O V
SCADA
GASOLINE
FuelCheck®
Controller
MOV

17. Tandem Sensor Technique
DIESEL
FuelCheck®
Probe B
fiberoptic
interconnect
(<= 2 km)
FuelCheck®
Probe A M O V
SCADA
GASOLINE
FuelCheck®
Controller
MOV

18. Tandem Sensor Technique
DIESEL
FuelCheck®
Probe B
fiberoptic
interconnect
(<= 2 km)
FuelCheck®
Probe A M O V
SCADA
GASOLINE
FuelCheck®
Controller
MOV

19. AUTOMATED PIPELINE BATCH CONTROL
THE FUTURE
AUTOMATED PIPELINE BATCH CONTROL

20. Goal of Pipeline Batch Automation
“fine tune” valve actuation to coincide EXACTLY with operator’s command based upon observation of interface detection system and volumetric correction.

21. Components Required Interface detector system (FuelCheck®)
Accurate flow measurement
Known values for pipe volumes (line pack)
Known values for valve activation time
Known values for min. and max. flow rates
Batch controller (flow computer or SCADA)

22. Flow Computer is Preferred Pipeline Batch Controller
Flow computer has faster I/O cycle
Flow computer vendor is more familiar with pipeline application
Some flow computers already have batch control parameters built into system together with line pack data

23. Automated Pipeline Batch Control (Flow Computer)
operator selects desired cut point from FuelCheck Probe A input B.
Flow computer uses flow rate, valve actuation time, and pipe volume (line pack) between meters/valves and sensors to compute and execute precise valve control at desired cut point. Control system comm. delays must also be considered.
HMI
Flow Computer
Valve Control
from
FuelCheck
Probe A
FuelCheck
Probe B
FLOWMETER to
FuelCheck
Probe A
Recommended minimum distance is 1-1/2 times valve actuation time at maximum flow rate
TO TANK B
TO TANK A
Recommended minimum distance is 10 minutes at maximum flow rate (up to 2 km)

24. Automated Pipeline Batch Control (SCADA)
operator selects desired cut point from input from FuelCheck Probe A B.
SCADA system uses flow rate, valve actuation time, and pipe volume between valves and sensors to compute and execute precise valve control at desired cut point. System comm delays must also be considered.
SCADA
from
FuelCheck
Probe A
valve control
FuelCheck® Controller
FuelCheck
Probe B
FLOWMETER to
FuelCheck
Probe A
Recommended minimum distance is 1-1/2 times valve actuation time at maximum flow rate
TO TANK B
TO TANK A
Recommended minimum distance is 10 minutes at maximum flow rate (up to 2 km)

25. Pipeline Batching Strategy
High energy product
(i.e., diesel)
CUT HERE
Low energy product
(i.e., gasoline)

26. Pipeline Batching Strategy
High value product
(i.e., premium gasoline)
CUT HERE
Lower value product
(i.e., regular gas)

27. Pipeline Batching Strategy
High energy product
(i.e., diesel)
Long transmix
Divert to slop tank
Lower energy
Higher value product
(i.e., Jet-A)

28. Recommended HMI trending and control enhancements
Both axes must have user-controlled scaling
X-axis on operator’s real-time trend should be volume instead of time
Real-time trend scroll rate should be based on volume rather than time
Use 3 vertical “sliders” to identify beginning and end of interface, and desired cut point
Show calculated interface volume based on slider positions
Show volume-driven (from flow meter) dynamic countdown timer for MUST COMMIT BATCH CUT
Show valve position indicators (if available)

29. Future Upgrades
Integrate interface detectors from upstream stations into batch control logic
Create computation of interface contamination of tank volumes based on dynamic inventory to decide whether or not to divert flow to slop tank
“Total pipeline batch control automation” (must do recommended enhancements first, and then will require a lot of programming, testing, and debugging to be reliable and trustworthy)