ATC 23540 - Houston Tx. 10-11 Feb 2014

ATC 23540 Stations and Terminals Modeling for Risk and Reliability Assessment Jose L. Martinez Gonzalez, Enrique Rodriguez Betancourt, Pemex Corporate, Irani Perez Taylor, Pemex Refining, Lorenzo Martinez Gomez, CyP and Augusto Garcia, SwRI

10‐12 February 2014 » Houston, Texas

Content • • • • • • • • • • • • •

Introduction Stations and Terminals taxonomy Model circuiting Model hierarchy in stations Circuiting terminals Stations and terminals processes Reliability definition Components matrix Failure mechanisms and threats Risk calculation approach Input model Case study Conclusion and next steps

Introduction •

• • •

•

Risk and reliability assessment in stations and terminals is complex for the amount of components involved and processes and functions acting simultaneously. However, there several elements in common between these facilities that allow defining circuits with similar configuration.

Most of assessment solutions are unfriendly and the analyst has to adapt his model to what it is available in a piece of software Risk models have to include what the operator sees in the facility and reflect actual conditions at the moment of the analysis The model has to suit different operators needs so applicable standards most comply internationally. Also potential users may speak different languages and the taxonomy of the model keeps the same meaning for everyone A very important issue is related to risk figures the operators expects to see after the assessment. Operator’s opinion is the best way to validate model’s accuracy and reliability

Stations and Terminals Modeling Taxonomy The standard ISO 14224 establishes that taxonomy is a systematic classification of items into generic groups based on factors possibly common to several of the items (1) Industry

Equipment subdivision

(3) Installation (4) Plant / Unit (5) Section / System (6) Equipment unit (7) Sub-unit (8) Component / Maintanable item (9) Part

Use / Location

(2) Business Category

Stations and Terminals Modeling Taxonomy 1. Industry – main activity, such oil industry, natural gas, petrochemical, refining, etc. (This value is mainly used by politicians) 2. Business category – business type or processing sequence, for instance: Upstream, midstream, and downstream.

3. Installation – refers to a specific business unit such as oil/gas production, transmission, refining, logistics, etc.

4. Plant / Unit – includes a big group of circuits such as platforms, storage tanks, etc.

5. Section / System – corresponds to main sections in a plant or systems within a circuit, such as compressors, loading / offloading facilities, etc.

6. Equipment Unit – includes specific equipment with one or more functions within a sub process, such as Exchange heaters, rotatory equipment, tubing, etc.

7. Subunit – refers to components that perform specific functions for equipment, such as lubrication, cooling, heating, etc.

8. Component / Maintainable Item – group of parts/spares for equipment that can be repaired or refurbished, such as couplings, lubrication pumps, filtering, etc.

9. Part – includes specific equipment pieces, such as sealing, tubing, joints, etc.

Model hierarchy in stations 1. The calculated risk value represents all circuits contribution in one average figure – A SINGLE RISK VALUE (AVERAGE)

2. Individual risk values for each circuit including a lower level risk contribution from systems considered as part of a sub‐process – A RISK VALUE PER CIRCUIT 3. Risk value per system considering all equipment contribution based on their specific functions

4. Risk value per individual equipment, considering all components influence that influence equipment functioning 5

5. Refers to maintainable items with a specific influence in equipment functioning – at this level no risk calculation will be performed. However, their influence will be within equipment risk assessment

Circuiting Terminals Circuit

Application

1.

Tanks – storage

SDT / MT

2.

Loading facility

SDT / MT

3.

Unloading facility

SDT / MT

4.

Dynamic equipment

SDT / MT

5.

6.

Fire prevention & protection Drainage

7.

Electric

SDT / MT

8.

O&M staff

SDT / MT

9.

Telecommunication

SDT / MT

SDT / MT SDT / MT

10. Process piping

SDT / MT

11. Physical protection

SDT / MT

12. Shop air

SDT / MT

13. Control/monitoring systems 14. Gas/liquid fuel

SDT / MT SDT / MT

15. Loading arm

MT

16. Buoy (SPM)

MT

Stations and terminals processes Purpose: define a customized configuration based on user needs to reproduce a model that better reflects condition of a terminal in terms of amount of components and their relationship to comply a specific process

Start

Circuit 1

Circuit 2

Circuit 3

Circuit x

Support circuit 1.1

Support circuit 2.1

Support circuit 3.1

Support circuit 4.1

Support circuit 1.2

Support circuit 2.2

Support circuit 3.2

Support circuit 4.2

Support circuit 1.3

Support circuit 2.3

Support circuit 3.3

Support circuit 4.3

Support circuit 1.x

Support circuit 2.x

Support circuit 3.x

Support circuit 4.x

Circuit A

Circuit B

Circuit C

Circuit Y

Main process happens here

Support processes help main process and some of them may influence main process continuity or interruption

Parallel processes do not affect main and support processes directly

Terminals processes mapping 1 Distribution process

5

Monitoring & control systems

Support processes aligned to main process

Dynamic equipment

Storage Tanks

13

2 or 3 Loaders/ Unloaders

Piping systems

Monitoring & control systems

Electrical system

13

Receiving process

Monitoring & control systems

7

7

Electric system

7

Electric system

7

Monitoring & control systems

13

Electric system

13

Operations & maintenance staff

8

Operations & maintenance staff

8

Air Supply Plant/Insts.

11

Air Supply Plant/Insts.

11

Gas / liquid fuel

instrumentation

4

Fire prevention & protection

6

Telecommunication

10

Operations & maintenance staff

12

Operations & maintenance staff

8

Drainage

Security systems

9

14

Parallel processes and associated circuits

8

Reference buffer

Processes Reliability Reliability can be measured as a frequency of failures within a certain period.

Serial Systems: Following figure shows systems arranged in series E1

E2

Ei-1

Ei

AND – applies when processes are dependent. Reliability of every component may affect or benefit others components. Reliability values are multiply to obtain a system reliability to complete a process

Parallel Systems: These systems are designed to comply with a specific and measurable reliability,. They do not depend on each others’ reliability in a direct way E1 E2 E3

OR – applies for independent processes and reliabilities are added: PoF = 1‐(1‐V1)*(1‐V2)*…(1‐Vn)

Serial Systems Circuit Tanks – storage Dynamic equipment Loading/unloading facilities

Scenario 1. Reference 2. Improvement R1 3. Improvement R2 4. Improvement R3

Reliability (%) 70 80 90

ID R1 R2 R3

Reliability R1

Reliability R2

Reliability R3

0.7 0.8 0.7 0.7

0.8 0.8 0.9 0.8

0.9 0.9 0.9 0.99

System Reliability 0.504 0.576 0.567 0.554

From the exercise it may be concluded that the more number of serial circuits in the terminal, the more vulnerable the process becomes, therefore some strategies may be established to reduce the amount of serial circuits or allow redundancy in weak circuits (This depends on availability of resources or profitability in that specific terminal).

Parallel Systems Scenario 1. Reference 2. Improve R1 3. Improve R2 4. Improve R3

Reliability R1

Reliability R2

Reliability R3

0.7 0.8 0.7 0.7

0.8 0.8 0.9 0.8

0.9 0.9 0.9 0.99

System Reliability 0.994 0.996 0.997 0.999

Although in Pemex a functionality scheme presents a wide variety of processes coexisting in the same facility, a prototype configuration was defined to include any circuit in the risk and reliability model. This lead to a components matrix definition to envisage any possible combination of circuits

Component Matrix Circuit 1.

Tanks – storage

2.

Loading facility

3.

Unloading facility

4.

Dynamic equipment

5.

Fire prevention & protection

6.

Drainage

7.

Electric

8.

O&M staff

9.

Telecommunication

10. Process piping 11. Physical protection 12. Shop air 13. Control/monitoring systems 14. Gas/liquid fuel

Stations / Terminals Pumping (12)

Compressor (12)

● ● ● ● ● ● ● ● ● ● ●

● ● ● ● ● ● ● ● ● ● ●

●

●

Reg/Met (14)

● ● ● ● ● ● ● ● ●

15. Loading arm 16. Buoy (SPM) 17. Vessels 18. Flow conditioning skid 19. Primary regulation equipment 20. Primary regulation equipment 21. Fluid quality analyzer skid

● ● ● ● ●

SDT (14)

MT (16)

● ● ● ● ● ● ● ● ● ● ● ● ● ●

● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●

Failure Mechanisms and Threat Matrix Defining this matrix allows anticipating PoF drivers for each circuit to be related with results of processes mapping. At this stage it is important to establish the difference between mechanism and failure threats

CIRCUIT Process piping Dynamic equipment Operation & maintenance staff Control & instrumentation Electric system Security & vulnerability Tanks Fuel system (gas/liquid) Drainage system Fire protection system

Failure Mechanisms and Threats in Stations Mechanical Integrity Safety Operation MAT

MEC

FAB/CONS

● ●

● ●

● ● ● ●

● ● ● ● ● ● ●

INST

ELEC

IOM

● ●

● ●

● ●

● ● ● ● ● ● ●

● ●

● ● ● ● ● ● ● ● ●

● ● ● ● ● ● ● ● ● ●

● ●

●

Telecommunication system

Air supply Plant/Instrumentation

TP

●

●

●

OFE

●

●

● ● ● ● ● ●

Total IM

● ●

6 6 1 5 7 5 6 6 6 6 5 6

Risk Calculation Approach The model is currently based in a semi quantitative approach while data is gathered to build up a history for a facility The risk of failure (RoF) is calculated as a function of the probability of failure (PoF) and the consequences (CoF)

Probability of Damage (PoD) = Exposure x (1 ‐ Mitigation) Probability of Failure (PoF) = PoD x (1‐ Resistance) The consequence side is assessed as follows: Poten al Loss = Hazard Area x ∑ (Receptor Unit Value x Receptor Density x Receptor Damage Rate) Exposure (Attack) Mitigation (Defense) Resistance (Survivality)

Risk Calculation Approach Risk

=

Events Km - year

$ USD Events

=

$ USD Km - year

AND / OR Gates AND – implies dependent measures (variables) that should be combined by multiplication to reflect and effect. Any sub-variable may have alone an important influence.

Mit and/or Res= V1*V2…Vn

OR – means independent events that may be added to calculate the probability that any single event will occur Mit and/or Res and/or PoD and/or PoF = 1-(1-V1)*(1-V2)*…(1-Vn) This approach allows to efficiently combine any variable without having to score or assign weightings in specific attributes

The complicated part of the model OREDA Data for components   

Identifying components Naming components (Taxonomy) Applying to all circuits beyond and further back  Calculating failure rates to obtain PoF and frequencies

Assembling equations according to Failure Mechanisms and Threat Matrix 

From Circuit to subunit calculations are performed to calculate PoF, CoF, RoF and reliability index  Circuits are switch “off” and “of” depending on station/terminal facility configuration

Calculations Calculation process is repeated for all facility components (recall model hierarchy) – this would go as a far as a dynamic segmentation in a pipeline – if the analyst requires a deeper detail in the calculations, risk figures are available at subunit level with a drill down ready to report at a maintainable item

Input Models  Stations and terminals models do not really use massive input to perform calculations of any nature. These models use a big amount of variables. However, these variables do not usually require stationing information (For instance, information every 10 inches)  A lot of information is provided only once to start building up a data base  Massive information for these models usually comes from inspections related to mechanical integrity, such as thickness surveys with non intrusive devices  The added value of this modeling is relating data to images to ease operator’s interpretation of risk values. Since facilities are non – stationing models, risk may be represented with buffers without affecting calculations  For the consequence part of the equation, facility location is important to calculate impacts  The application, currently under development, considers a model builder based on satellite imaging where the user defines buffers to recognize all circuits in the facility.

Each buffer gets data trough tables linked to the process diagram and circuited image. It also has the capability of auditing data and reporting errors or inconsistencies  The application is very visual and applies color codes to show risk and reliability values.

Station Model Output As a part of calibration exercise a compressor station was modeled Next figure shows probability of failure values for the dynamic equipment circuit. The algorithm was applied to a compressor station

Dynamic Equipment Probability of Failure ‐ Station Emiliano Zapata (Gas Turbine TC‐1) Probability of Faliure (Failures/year)

MEC MAT CNI 6.00 5.00 4.00 3.00 2.00 1.00 0.00

ELE EEF TPD IOP IMN FAB

Equipment

Station Model Output Risk assessment output at subunit level:

Probability of Faliure (failures/year)

Dynamic Equipment Probability of Failure ‐ Station Emiliano Zapata (Gas Turbine TC‐1)

1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00

MEC MAT CNI ELE EEF TPD IOP IMN FAB

Equipment

Terminal Model Output To illustrate the way the model works for terminals the Tanks – Storage Circuit is shown in next figure Plate 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Actual Thickness [In] 0.456 0.479 0.477 0.256 0.324 0.474 0.391 0.379 0.331 0.481 0.489 0.341 0.345 0.329 0.281 0.478 0.452 0.331

Corrosion rate [Mpy] 4.4 2.1 2.3 24.4 17.6 2.6 10.9 12.1 16.9 1.9 1.1 15.9 15.5 17.1 21.9 2.2 4.8 16.9

TTF [Years] 103.6 228.1 207.4 10.5 18.4 182.3 35.9 31.3 19.6 253.2 444.5 21.4 22.3 19.2 12.8 217.3 94.2 19.6

PoF -Plate- PoF -Shell0.19% 0.09% 0.10% 9.09% 5.29% 0.11% 0.56% 0.64% 4.98% 0.08% 0.04% 0.93% 0.89% 5.06% 7.50% 0.09% 0.21% 4.98%

9.09%

Terminal Model Output

Model circuiting through buffer definition based on satellite image

Terminal Model Output

Model circuiting definition through 3D model related to data input

Terminal Model Output

Risk assessment output representation in 3D models with color coding • Red is high risk • Yellow is risk management • Red is intolerable

Conclusion  Current risk assessment models for facilities do not really take advantage of all information and systems available. IT solutions tend to be more graphic and visual.  Field engineers have to see themselves in the model to trust it and adopt it as a supporting tool  These developments are currently sponsored by the National Science and Technology Council in Mexico to encourage researchers and engineers to innovate in the oil industry. The final product will cover risk assessment models for pipelines, stations and terminals, using state of the art technology and takes advantage of the participation of the Academy and Industry to combine knowledge and experience to obtain a sustainable application  All models will be tested, calibrated and validated with existing facilities. In some cases the models will include model scale reproduction in research facilities. It is expected that these models are useful when released for use in the industry to support integrity and reliability management processes

Acknowledgements  To our engineering team – locals and from overseas  To Pemex for accepting giving up some pennies from each crude oil barrel they sell to support the Funding  To Enrique, Lorenzo, Lorenzo, Augusto, Irani, Arturo and Jaime, for believing and supporting this project  To National Science and Technology Council in Mexico  To the ATC Committee for allowing us to present and spread out our work

Thank You!

10‐12 February 2014 » Houston, Texas