Pipeline operation through scada

PIPELINE OPERATIONSPIPELINE OPERATIONSTHROUGH SCADATHROUGH SCADA

K Kumar

DGM(T&I), PL . HO

PIPELINE OPERATIONS THROUGH SCADA

Objectives of SCADA systemObjectives of SCADA system

• To provide effective & efficient monitoring and control of To provide effective & efficient monitoring and control of entire pipeline network. entire pipeline network.

• Remote control of important station equipment, process set Remote control of important station equipment, process set points & block valves from SCC / MCC.points & block valves from SCC / MCC.

SCADASCADA

• Emergency shutdown of entire pipeline from MCC.Emergency shutdown of entire pipeline from MCC.• Acquisition & display of pipeline parameters, alarms from Acquisition & display of pipeline parameters, alarms from

attended stations, scraper stations, C.P. Stations & block attended stations, scraper stations, C.P. Stations & block valves at MCC.valves at MCC.


TANKS

TYPICAL ORIGINATING PUMP STN LINE DIAGRAM

MAINLINE PUMPING SECTION

BOOSTER SECTIONSTRAINER SECTION

FLOW METER

MASTER METER

SCRAPPER LAUNCHING

BARRELTION

DENSITY METER

MOV

NRV

HOV

PRESSURE/TEMPERATURE INSTRUMENTS

SUMP PUMP &

TANK


TANK AND MANIFOLD INTERLOCKS LOGIC

LS, LT

MANIFOLD

TO BOOSTERS

TANK LINEUP CONDITIONS:

1. Sufficient ullage in the tank ensured by LT.2. Tank Valve will be opened when there is no

Low Alarm3. System will allow only one tank valve at a time.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

condition will ensure shutdown of equipments.


BOOSTERS

BOOSTERS LINE UP LOGIC


1.1. Any one of the tank and manifold valve Any one of the tank and manifold valve should be inn open condition.should be inn open condition.

2.2. Discharge valve of the booster should be Discharge valve of the booster should be closed.closed.

3.3. No faults in the booster alarms should exist.No faults in the booster alarms should exist.4.4. Maximum only 2 Nos. of boosters can start.Maximum only 2 Nos. of boosters can start.5.5. Start command opens cution valve, then to Start command opens cution valve, then to

pump. Once pump runs discharge valve is pump. Once pump runs discharge valve is opened.opened.

6.6. Suction Pressure alarm comes online after a Suction Pressure alarm comes online after a time delay.time delay.

7.7. Any alarm initiation trips the boosters.Any alarm initiation trips the boosters.

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.


DISCHARGE MOVFAILED TO CLOSE

WITH IN PRESET TIME?(120 SEC)


PT

PT MAINLINE PUMPING UNITS

PI

PS

PI

PS

PI

PSPI

PS

PI PS PTBP

BP

AUTOMATIC CONTROL OPERATION

TANK

PSPI

PS

PI

PS

PS PS

TM

PID LOOP

SP

FP

DP

SET POINT CONTROLLERS

LOW

SIGNAL

SELECTOR

GOVERNOR / VFD / CONTROLVALVE


S T

R.

SRB

TM

TM

DPI

PI

SD

SD

PTPS

PT PIPS

PCV

DM

LS, LT

PT

BP

FC

LOW

SIGNAL

SELECTOR

TYPICAL CONTROL LOOP OF RECEIVING STATION


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

Independent Control System Irrespective of SCADAPIPELINE OPERATIONS THROUGH SCADA

20

CONTROL SYSTEM

During the scan, a PLC …

Monitors Inputs

Changes Outputs

Executes ProgramScan


TYPICAL SCADA ARRANGEMENT

MCC

COMMUNICATION SERVER

BVRTU

SCC,Originating

StationBV

RTU

SCC,Intermediate

Station

BVRTU

SCC,Delivery Station

COMMUNICATION LINK


DUAL REDUNDANT 100 MBPS ETHERNET LAN

Interface between Printers & Dual LAN

OPERATOR WORKSTATIONS (32BIT)

19” Fat Mon.

In owner’s OFC based communication system provision shall be made for Ethernet Interface

point to point redundant communication with each PLC of SCCs

Multi drop redundant communication with RTUs of block valves

DOT MATRIX PRINTER

DUAL REDUNDANT SCADA MCS cum SCC SERVERS (32

BIT)15” Flat Mon.

TYPICAL MCS cum SCC CONFIGURATION

CPU, Memory, comm. Module, I/O controller, power supply

RTU / RTU / PLC

MODBUS Interface to third party devices e.g. flow computers, RTG, VFD etc.

APPLICATION SERVERS (32 BIT)

15” Flat Mon.

LASERJET PRINTER

Communication Server / FES

PSU

CPU

COM

IOC

PSU

CPU

COM

IOC

I/O MODULES

FIELD DEVICES

50”TFTScreen Display

SIC terminal (32 BIT)15” Flat Mon.

V.28/Ethernet

Ethernet

ENGG/PROGRAMMING TERMINAL 15” Flat

Mon.


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SCADA

Major functions of SCADA system –• Data acquisition / Communication

• Alarm & Event processing

• Control processing/commands

• Trend generation

• Shift / Daily /Maintenance Reports

• Management Information Reports


APPLICATION SOFTWARE • LEAK DETECTION & LOCATION MODULE

Sensing Pipeline Leakage and Location

• BATCH TRACKING/INTERFACE ANALYSISCalculation of motion and position of batches

• PIG TRACKINGTracks 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)


LEAK DETECTION SYSTEMLEAK 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


LDS Functional OverviewLDS Functional Overview

Dynamic flow balance methodDynamic flow balance method

A simple LDS could be based upon detecting A simple LDS could be based upon detecting an imbalance between a measured inlet flow an imbalance between a measured inlet flow and a measured outlet flow (ie Net Volume and a measured outlet flow (ie Net Volume Line Balance)Line Balance)

Qin Qout


Pu

Normal Pressure Profile

Pressure Profile fully developed due to leak

Pressure

Pipe Length


Ideal Pressure Control UpstreamIdeal Pressure Control Upstream

With ideal pressure control upstreamWith ideal pressure control upstream UPD = PDUPD = PDCALCCALC - PD - PDMEASMEAS

UPD UPD is Unexpected Pressure Downstreamis Unexpected Pressure DownstreamPDPDCALCCALC is Calculated Pressure Downstreamis Calculated Pressure DownstreamPDPDMEAS MEAS is Measured Pressure Downstreamis Measured Pressure Downstream

UPD = 0 implies no leakUPD = 0 implies no leak

PDMEAS

UPD

PDCALC



Ideal Pressure Control UpstreamIdeal Pressure Control Upstream

The pressure profile is capable of indicating leaks, butThe pressure profile is capable of indicating leaks, but small leaks have minimal effect on pressuresmall leaks have minimal effect on pressure the leak cannot be locatedthe leak cannot be located difficult to filter out normal pressure variationsdifficult to filter out normal pressure variations

Profiling the flow using flow control downstream Profiling the flow using flow control downstream increases the model accuracyincreases the model accuracy



Pressure Profiling (Upstream Pressure Control)Pressure Profiling (Upstream Pressure Control)

Pu

Pd

Pressure Profile under development due to leak (dashed lines)

Normal Pressure Profile

Pressure Profile fully developed due to leak

Pressure

Pipe Length



Ideal Flow Control DownstreamIdeal Flow Control Downstream

With ideal flow control downstreamWith ideal flow control downstream UFU = QUUFU = QUMEASMEAS - QU - QUCALCCALC

UFU UFU is Unexpected Flow Upstreamis Unexpected Flow UpstreamQUQUCALCCALC is Calculated Flow Upstream is Calculated Flow Upstream QUQUMEAS MEAS is Measured Flow Upstreamis Measured Flow Upstream

UFU = 0 implies no leakUFU = 0 implies no leak

QUCALCNormal Flow Profile

Flow Profile fully developed due to leak

Flow

Pipe Length

UFU

QUMEAS



Flow Profiling (Downstream Flow Control)Flow Profiling (Downstream Flow Control)

QU

QD

Flow Profile under development due to leak (dashed lines)

Normal Flow Profile

Flow Profile fully developed due to leak

Flow

Pipe Length


MODEL BASED LEAK MODEL BASED LEAK DETECTIONDETECTION



Response Time SeriesResponse Time Series

response

time

threshold.

leakoccurs

t 1 t 2

detection time

level 1 level 2 level 3 level 4

event periods

response levels


PRESSURE DROP METHOD- leak notified


Typical leak sensitivity data on dynamic Typical leak sensitivity data on dynamic

flowflow

% leak% leak LocationLocation timetime

2%2% + + 10 km10 km 20-30 mins20-30 mins

5%5% + + 5 km5 km 15-20 mins15-20 mins

10%10% + + 2 km2 km 5 mins5 mins


APPLICATION SOFTWARE • LEAK DETECTION & LOCATION MODULE

Sensing Pipeline Leakage and Location

• BATCH TRACKING/INTERFACE ANALYSISCalculation of motion and position of batches

• PIG TRACKINGTracks 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)


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 HIRED COMMUNICATION TO SCCs WILL HELP IN OPERATING FROM MCC WITHOUT APPLICATIONSOFTWARE .

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

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Data is acquired from field sensors / instrumentsData is acquired from field sensors / instruments Data is processed for monitoring and control of Engines/Motors, Valves Data is processed for monitoring and control of Engines/Motors, Valves

etc.etc. Supports operator decisions; reports and isolates abnormal situationsSupports operator decisions; reports and isolates abnormal situations Operator settable alarms for station from centralized master station for Operator settable alarms for station from centralized master station for

pressure and flowpressure and flow Emergency shutdown of entire pipeline from MCC in a defined sequence Emergency shutdown of entire pipeline from MCC in a defined sequence

starting from the terminal station so as to keep the line pressurized .starting from the terminal station so as to keep the line pressurized . Acquires and displays repeater data such as pressure, temperature, MOV Acquires and displays repeater data such as pressure, temperature, MOV

status, intrusion alarms. status, intrusion alarms. The block valve under the respective station can be locally controlled by The block valve under the respective station can be locally controlled by

the station control centre in case master-station communication fails.the station control centre in case master-station communication fails.

OPERATIONAL INFORMATION AND CONTROLOPERATIONAL INFORMATION AND CONTROLSYSTEM CAPABILITIES AND BENEFITSYSTEM CAPABILITIES AND BENEFIT

SYSTEM CAPABILITIES AND BENEFITSYSTEM CAPABILITIES AND BENEFIT

OPERATIONAL INFORMATION AND CONTROLOPERATIONAL INFORMATION AND CONTROL

Data is communicated over dedicated Communication channels Data is communicated over dedicated Communication channels to local and centrally located system at remoteto local and centrally located system at remote

When the communication between master and local station/ When the communication between master and local station/ repeater fails, the system maintains the previous state of repeater fails, the system maintains the previous state of operationi.e. there shall not be operational shutdwn.operationi.e. there shall not be operational shutdwn.

Communication failure indication shall be messaged to the Communication failure indication shall be messaged to the operator.operator.

While controlling the SCC from MCC by way of commands or While controlling the SCC from MCC by way of commands or change of set points, confirmation is sought from the address change of set points, confirmation is sought from the address before execution of command/ change of set point takes place.before execution of command/ change of set point takes place.

Bump less transfer from local station control to Master station Bump less transfer from local station control to Master station and Vice versa.and Vice versa.

Can remotely prove the flow meters and effect calibration Can remotely prove the flow meters and effect calibration factors.factors.

SYSTEM CAPABILITIES AND BENEFITSYSTEM CAPABILITIES AND BENEFIT

MAINTENANCE BENEFITSMAINTENANCE BENEFITS Data is stored as history Data is stored as history Archives data and alarms for future analysisArchives data and alarms for future analysis Generates hourly and daily shift reportsGenerates hourly and daily shift reports Generates equipment running hour reportGenerates equipment running hour report Acquires and displays parameters of CP system such Acquires and displays parameters of CP system such

as power availability, PSP etc.as power availability, PSP etc. Remote and auto start of DG set in RCPsRemote and auto start of DG set in RCPs Event database will maintain all alarms, alarm Event database will maintain all alarms, alarm

acknowledgements, return to normal process, acknowledgements, return to normal process, operator control actions.operator control actions.

On-line data base can be modified from Master.On-line data base can be modified from Master. Permits security level log-ins.Permits security level log-ins.

Pipeline operation through scada

Technology

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