Product Interface Detection in batched multi-product liquid metering J.L. “Larry Taylor, III ISA MEMBER 32081934 OMNTEC – Innovative Sensor Solutions ISA (D) Expo 2005 Delhi, India 2 – 4 December 2005

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

Multi-Product Interface Detection: THE CHALLENGE

Transmix Minimization (SLOP) TRANSMIX B B

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

The Challenge REDUCE TRANSMIX IMPROVE PURITY

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

Conventional Approach Use densitometer to identify interface Move densitometer upstream

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

THE SOLUTION FuelCheck®

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

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

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

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”)

FuelCheck® Response

Tandem Sensor Technique valve response time DIESEL FuelCheck® Probe B fiberoptic interconnect (<= 2 km) FuelCheck® Probe A 5 - 10 minutes M O V SCADA GASOLINE FuelCheck® Controller MOV

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

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

AUTOMATED PIPELINE BATCH CONTROL THE FUTURE AUTOMATED PIPELINE BATCH CONTROL

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.

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)

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

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)

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)

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

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

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

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)

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)