The document discusses pipeline operations through a SCADA system. The objectives of the SCADA system are to provide effective monitoring and control of the pipeline network through remote control of equipment and emergency shutdown capabilities. It describes the typical configuration and components of a SCADA system including master control stations, communication networks and field devices. It also summarizes the major functions and capabilities of a SCADA system for pipeline operations such as data acquisition, control processing, alarm handling, reporting and maintenance benefits.
Optimizing Pipeline Operations with SCADA Monitoring
1. PIPELINE OPERATIONS
THROUGH SCADA
K Kumar
DGM(T&I), PL . HO
PIPELINE OPERATIONS THROUGH SCADA
2. SCADA
Objectives of SCADA system
• To provide effective & efficient monitoring and control of
entire pipeline network.
• Remote control of important station equipment, process set
points & block valves from SCC / MCC.
• Emergency shutdown of entire pipeline from MCC.
• Acquisition & display of pipeline parameters, alarms from
attended stations, scraper stations, C.P. Stations & block
valves at MCC.
PIPELINE OPERATIONS THROUGH SCADA
3. TYPICAL ORIGINATING PUMP STN LINE DIAGRAM
STRAINER FLOW MASTER
BOOSTER SECTION
SECTION METER METER
TANKS
DENSITY
METER
MAINLINE
PUMPING SECTION
SUMP
PUMP &
TANK
MOV PRESSURE/TEMPERATURE
INSTRUMENTS SCRAPPER
LAUNCHING
NRV
BARRELTION
HOV
PIPELINE OPERATIONS THROUGH SCADA
4. TANK AND MANIFOLD INTERLOCKS LOGIC
LS,
LT
TANK LINEUP CONDITIONS:
1. Sufficient ullage in the tank ensured by LT.
2. Tank Valve will be opened when there is no
Low Alarm
3. System will allow only one tank valve at a time.
TO BOOSTERS 4. During changeover 25% valve opening gives
5. command for the closure of other tank valve.
6. Manifold valve operation is also similar.
7. Failure of above operation, sequence incomplete
MANIFOLD
condition will ensure shutdown of equipments.
PIPELINE OPERATIONS THROUGH SCADA
5. BOOSTERS LINE UP LOGIC
BOOSTERS
1. Any one of the tank and manifold valve
should be inn open condition.
2. Discharge valve of the booster should be
closed.
3. No faults in the booster alarms should exist.
4. Maximum only 2 Nos. of boosters can start.
5. Start command opens cution valve, then to
pump. Once pump runs discharge valve is
opened.
6. Suction Pressure alarm comes online after a
time delay.
7. Any alarm initiation trips the boosters.
PIPELINE OPERATIONS THROUGH SCADA
6. MAINLINE PUMP LINE UP LOGIC
1. Mainline Pumps are either Engine Driven or Motor Driven.
2. In case of Engine Driven Pump, a self contained control panel
ensures the healthy status of all engine/pump parameters.
3. In case of Motor Driven Pump, the health of the equipment is
monitored directly by the SCC.
4. Precondition to start : Discharge valve should be closed, No fault
condition exist confirms the availability of the equipment.
5. Start command opens suction valve, then to pump. Once pump runs
opens discharge valve.
6. Any failure in the sequence will not allow the pump to start.
7. While pump running, any alarm of the pump/station like high discharge, ESD,
Sump Tank Level Hi-Hi etc. will trip the system and isolates the system by
closing the valves.
8. All important alarms are derived from Primary instruments as well as
secondary instruments to ensure fail safe operation.
PIPELINE OPERATIONS THROUGH SCADA
15. AUTOMATIC CONTROL OPERATION
PT
PT
MAINLINE PUMPING UNITS
BP PI PS PT
TANK TM
PI PS PI PI PS PI PI PS
PI
PS PS PS PS PS
BP PS
PID LOOP
SET POINT
CONTROLLERS
FP
LOW
GOVERNOR /
SP SIGNAL VFD / CONTROL
VALVE
SELECTOR
DP
PIPELINE OPERATIONS THROUGH SCADA
17. TYPICAL CONTROL LOOP OF RECEIVING STATION
PT PS PI PI
SD
SRB
SD
PCV
PT
BP LOW
S
DPI
T
R.
SIGNAL
FC
SELECT
OR
T T
M LS,
M LT
PS PT
DM
PIPELINE OPERATIONS THROUGH SCADA
19. LOCAL CONTROL SYSTEM /
PROGRAMMABLE LOGIC CONTROL SYSTEM
OBJECTIVES ARE -LOGIC CONTROL - PROCESS CONTROL
COMMUNICATION WITH SCC
Digital I/Os
Analog I/Os
CPU & Communication interface
Field Instruments
PIPELINE OPERATIONS THROUGH SCADA Independent Control System Irrespective of SCADA
20. CONTROL SYSTEM
During the scan, a PLC …
Monitors Inputs
Scan Executes Program
Changes Outputs
20
PIPELINE OPERATIONS THROUGH SCADA
21. TYPICAL SCADA ARRANGEMENT
MCC
COMMUNICATION
SERVER
COMMUNICATION LINK
SCC, SCC, SCC,
Originating BV BV Intermediate BV Delivery
Station RTU RTU Station RTU Station
PIPELINE OPERATIONS THROUGH SCADA
22. APPLICATION SERVERS (32 DUAL REDUNDANT SCADA OPERATOR
ENGG/PROGRAMMING BIT) MCS cum SCC SERVERS (32 WORKSTATIONS (32BIT) SIC terminal (32 BIT)
TERMINAL 15” Flat 15” Flat Mon. BIT) 19” Fat Mon. 50”TFT 15” Flat Mon.
Mon. 15” Flat Mon. Screen
Display
DUAL REDUNDANT
100 MBPS ETHERNET LAN
In owner’s OFC
based
Interface between communication
RTU / PLC Printers & Dual LAN
system provision
CPU, Memory, P C C I P C C I shall be made for
comm. Module, I/O S P O O S P O O
Ethernet Interface
controller, power U U M C U U M C
supply
DOT MATRIX
point to point
PRINTER redundant
communication
Communication with each PLC of
Server / FES
SCCs
Ethernet
LASERJET
PRINTER
Multi drop
I/O MODULES
redundant
communication
with RTUs of
MODBUS Interface block valves
FIELD DEVICES
to third party V.28/Ethernet
devices e.g. flow
computers, RTG,
VFD etc.
TYPICAL MCS cum SCC CONFIGURATION
PIPELINE OPERATIONS THROUGH SCADA
23. SCADA
Major functions of SCADA system –
• Data acquisition / Communication
• Alarm & Event processing
• Control processing/commands
• Trend generation
• Shift / Daily /Maintenance Reports
• Management Information Reports
23
PIPELINE OPERATIONS THROUGH SCADA
24. APPLICATION SOFTWARE
• LEAK DETECTION & LOCATION MODULE
Sensing Pipeline Leakage and Location
• BATCH TRACKING/INTERFACE ANALYSIS
Calculation of motion and position of batches
• PIG TRACKING
Tracks Movement of pig
• LOOK AHEAD MODEL
To predict future trends of pressures and flow with respect to pump changes
• PIPELINE EFFICIENCY
Recommends for cleaning of pipeline
• PREDICTIVE MODEL
Simulates the hydraulic dynamics of the pipeline (Offline)
PIPELINE OPERATIONS THROUGH SCADA
25. LEAK DETECTION SYSTEM
Typical Leak detection system consists following software
modules :
WHEN LINE IN OPERATION
Pressure & Flow Profile Module / Pressure Wave Module
-To detect leak and location
Volume balance method : To detect leak only
UNDER SHUT IN CONDITION
Pressure wave module : To detect leak and location
Pressure Drop method : To detect leak only
PIPELINE OPERATIONS THROUGH SCADA
26. LDS Functional Overview
Dynamic flow balance method
A simple LDS could be based upon detecting an
imbalance between a measured inlet flow and a
measured outlet flow (ie Net Volume Line
Balance)
Qin Qout
PIPELINE OPERATIONS THROUGH SCADA
27. LDS Functional Overview
Ideal Pressure Control Upstream
Pu
Normal Pressure Profile
Pressure
Pressure Profile fully
developed due to leak
PDCALC
Pipe Length
UPD
With ideal pressure control upstream PDMEAS
UPD = PDCALC - PDMEAS
UPD is Unexpected Pressure Downstream
PDCALC is Calculated Pressure Downstream
PDMEAS is Measured Pressure Downstream
UPD = 0 implies no leak
PIPELINE OPERATIONS THROUGH SCADA
28. LDS Functional Overview
Ideal Pressure Control Upstream
The pressure profile is capable of indicating leaks, but
small leaks have minimal effect on pressure
the leak cannot be located
difficult to filter out normal pressure variations
Profiling the flow using flow control downstream
increases the model accuracy
PIPELINE OPERATIONS THROUGH SCADA
29. LDS Functional Overview
Pressure Profiling (Upstream Pressure Control)
Pu
Normal Pressure Profile
Pressure Profile under
Pressure development due to leak (dashed
lines)
Pressure Profile fully
developed due to leak
Pd
Pipe Length
PIPELINE OPERATIONS THROUGH SCADA
30. LDS Functional Overview
Ideal Flow Control Downstream
Flow Profile fully developed
due to leak
QUMEAS
UFU
QUCALC Normal Flow Profile
Flow
Pipe Length
With ideal flow control downstream
UFU = QUMEAS - QUCALC
UFU is Unexpected Flow Upstream
QU CALC
is Calculated Flow Upstream
QU MEAS
is Measured Flow Upstream
UFU = 0 implies no leak
PIPELINE OPERATIONS THROUGH SCADA
31. LDS Functional Overview
Flow Profiling (Downstream Flow Control)
Flow Profile fully
QU developed due to leak
QD
Normal Flow Profile
Flow Profile under development
Flow due to leak (dashed lines)
Pipe Length
PIPELINE OPERATIONS THROUGH SCADA
35. Typical leak sensitivity data on dynamic flow
% leak Location time
2% + 10 km 20-30 mins
5% + 5 km 15-20 mins
10% + 2 km 5 mins
PIPELINE OPERATIONS THROUGH SCADA
36. APPLICATION SOFTWARE
• LEAK DETECTION & LOCATION MODULE
Sensing Pipeline Leakage and Location
• BATCH TRACKING/INTERFACE ANALYSIS
Calculation of motion and position of batches
• PIG TRACKING
Tracks Movement of pig
• LOOK AHEAD MODEL
To predict future trends of pressures and flow with respect to pump changes
• PIPELINE EFFICIENCY
Recommends for cleaning of pipeline
• PREDICTIVE MODEL
Simulates the hydraulic dynamics of the pipeline (Offline)
PIPELINE OPERATIONS THROUGH SCADA
37. SYSTEM RELIABILITY
1. MAJOR EQUIPMENT LIKE PLC, SCADA SERVER ARE AVAILABLE
IN HOT STANDBY MODE. ONLY STANDBY IS NOT AVAILABLE
FOR RTUs.
2. FAILURE OF COMMUNICATION WILL INHIBIT THE CONTROL
COMMANDS. ALTERNATE HIREDCOMMUNICATION TO SCCs
WILL HELP IN OPERATING FROM MCC WITHOUT APPLICATION
SOFTWARE .
3. STATION LEAKAGES CANNOT BE DETECTED. CCTV WITH
MOTION SENSOR – GENERATE ALARM
4. PROPER MAINTENANCE OF STATION WITH TO REGARD
LEAKS/EQUIPMENT CAN ENSURE RELIABLE FUNCTIONING OF
SCADA SYSTEM
39. SYSTEM CAPABILITIES AND BENEFIT
OPERATIONAL INFORMATION AND CONTROL
Data is acquired from field sensors / instruments
Data is processed for monitoring and control of
Engines/Motors, Valves etc.
Supports operator decisions; reports and isolates abnormal
situations
Operator settable alarms for station from centralized master
station for pressure and flow
Emergency shutdown of entire pipeline from MCC in a
defined sequence starting from the terminal station so as to
keep the line pressurized .
Acquires and displays repeater data such as pressure,
temperature, MOV status, intrusion alarms.
The block valve under the respective station can be locally
controlled by the station control centre in case master-
station communication fails.
40. SYSTEM CAPABILITIES AND BENEFIT
OPERATIONAL INFORMATION AND CONTROL
Data is communicated over dedicated Communication channels
to local and centrally located system at remote
When the communication between master and local station/
repeater fails, the system maintains the previous state of
operationi.e. there shall not be operational shutdwn.
Communication failure indication shall be messaged to the
operator.
While controlling the SCC from MCC by way of commands or
change of set points, confirmation is sought from the address
before execution of command/ change of set point takes place.
Bump less transfer from local station control to Master station
and Vice versa.
Can remotely prove the flow meters and effect calibration
factors.
41. SYSTEM CAPABILITIES AND BENEFIT
MAINTENANCE BENEFITS
Data is stored as history
Archives data and alarms for future analysis
Generates hourly and daily shift reports
Generates equipment running hour report
Acquires and displays parameters of CP system such
as power availability, PSP etc.
Remote and auto start of DG set in RCPs
Event database will maintain all alarms, alarm
acknowledgements, return to normal process,
operator control actions.
On-line data base can be modified from Master.
Permits security level log-ins.
Hinweis der Redaktion
This slide has an animated product wave-front passing from inlet to outlet - explain how real systems are continually line packing and unpacking and thus introduce the idea of normal operational variations in measured values etc
Introduce the idea of unexpected values forming the basis of alarms Simple principle determines downstream UP response UPd = 0 does imply no leak but that doesn't mean that UPd > 0 implies a leak filtering will also come into the equation later
Now there is a need for more information - introduce the ideal of using flow readings
ANIMATED SLIDE showing pipe with associated pressure/distance graph 1st click - normal profile, gas in pipe 2nd click - leak develops, pressure upstream is constant under assumed pressure control, downstream pressure drops 3rd click - new profile due to leak
Much the same as before... An unexpected flow response will indicate the leak size (if its not coming out the other end then it must be going somewhere - but remember about line-packing etc) Once again it still requires clever filtering
ANIMATED SLIDE showing pipe with associated flow/distance graph 1st click - normal profile, gas in pipe 2nd click - leak develops, flow downstream is constant under assumed flow control, upstream flow must increase 3rd click - new profile due to leak
Each filter will generate response levels depending on how the leak response compares to its threshold A leak situation is generated for any response level > 1 otherwise it is a no leak situation t1 and t2 must be > than the filter averaging period + 1 scan time (15s)