how to avoid pit falls in design basis rev 3

How to Avoid Pit falls in Design Basis ?

Krishna Rajasekhar POLAPRAGADA M. Tech, D.I.M,

Principal Process Engineer SLFE- Kingdom of Saudi Arabia

Krishna- Principal process Engineer SLFE- Al-Khobar- K.S.A

What types of Risks exist in projects ?

What we need to Focus on ?


Cost ? Schedule ?

Safety ?

OR Missing Design intent ?

Gulf of Mexico Oil well in 2010- one disaster costs USD 50 Billion to BP.


Why focus on Design ?

• Operators may not be trained !• 100% Safe Systems may not be present ! • Instruments or equipments may fail ! • Natural disasters might occur ! • We may not learn from past failures! But all of us want DESIGN to work !


Why Designs fail ? - Inadequate protection – no. of Cheese layers. - Lack of data /accurate data - Cost/Schedule constraints - Lack of design expertise/training - Under-developed or agreed design

standards/protocols. - Rare risk break-downs. Eg. Earth Quake or Tsunami.- Inadequate Design Basis- Frequent changes to Design Basis - Ownership of Design Basis

document.

Krishna- Principal process Engineer -SLFE- Al-Khobar- K.S.A

TYPICAL DESIGN BASIS PIT–FALLS 1. Ownership of The Document - Client or Designer ? 2. Project Site location and Design office distance Eg. Project site is Middle East and Design office in Houston 3. Under developed Document (incomplete or grey areas ) 4. Lack of Data/Clarification and communication. 5. Change in conditions since finalization of original design intent.6. Design Basis and Beyond Design Basis 7. Lack of risk based evaluation of Design Basis

.


Elements of Design Basis


Case studies of Design Basis failures • Case 1 – DATA VALIDATION ERRORS. Eg. Rain fall – Nil . Humidity – Nil

Summer Max. temp. 440C in Saudi Arabia • Case 2 – NON REPRENTATIVE SAMPLES - Eg. Latest Crude assay not available. • Case 3 – FEED STOCK CHANGE - Eg. Sulfur units designed for 80:20 AL/AH

vs Sweet Bombay high crude processed .• Case 4- SPECIFICATION CHANGE : Eg. Fuel gas H2S content variance with design basis.• Case 5- BEYOND DESIGN BASIS Eg. Earth quake zone 4 vs 5


Case 3. Sulfur Recovery Units in Refinery

Year 1980. Project site : 3 Refineries in India

Design Basis : Crude blend of Arabian Light 80% and Arabian Heavy crude 20 %. Sulfur content 1.8 % Actual : Bombay High crude : Sulfur content < 0.3 %.

Result : Plant had to operate at < 7 % Turn down. condensers plugged. Furnace did not operate . Units have to modified/de-rated. RISK : USD 100 Million.


Case 3 -Low Flow Turn down areas


Low flow effected areas


Case 3 -Process Design issues in SRU

• Normal Design Turn down ratio is 20-30%

• Gases with an H2S content of over 25% are suitable for the recovery of sulfur in straight-through Claus plants while alternate configurations such as a split-flow set up or feed and air preheating can be used to process leaner feeds.

• With change to Sweet Crude , Turn down reduced to 7 % and caused shutdown due to plugging and leaking of condenser .

• Initiating a major revamp costing 40% of original capital costs.

https://en.wikipedia.org/wiki/Hydrogen_sulfide




Case 3 – Possible solutions

• Design for a large basket of crudes – cost impact

• Build Modular Equipment – 2 parallel Trains – cost impact

• Select a process which has low Turn down ratio.

• Operational strategy during change to sweet crude.

Case 4 -Fuel gas for Boiler in Oil and Gas plant

Year 2000. Project site : Oil& Gas filed in Middle East

Design Basis : Nil H2 S in Fuel gas

Actual : H2 S in Fuel Gas was 10,000 ppm.

Result : Burner damages. Boiler tubes corrosion and failure. Final replacement of Boilers. potential loss of production.

RISK : USD 100 Million Krishna- Principal process Engineer SLFE- Al-Khobar- K.S.A

Case 5 : Beyond Design Basis - Year 1998. Project site : Jamnagar – India

Design Basis : Earth quake Zone 4

Actual : Earth Quake Zone 5

Risk : or any where above USD 5 Billion

Actual Cost saved was USD 5 Billion by building Refinery beyond Design Basis .

Note : Earth Quake occurred at Richter scale 8.



Richter scale The Richter magnitude scale (also Richter scale) assigns a magnitude number to quantify the energy released by an earthquake. The Richter scale, developed in the 1930s, is a base-10 logarithmic scale, which defines magnitude as the logarithm of the ratio of the amplitude of the seismic waves to an arbitrary, minor amplitude.As measured with a seismometer, an earthquake that registers 5.0 on the Richter scale has a shaking amplitude 10 times that of an earthquake that registered 4.0, and thus corresponds to a release of energy 31.6 times that released by the lesser earthquake.[

https://en.wikipedia.org/wiki/Earthquake

https://en.wikipedia.org/wiki/Decimal

https://en.wikipedia.org/wiki/Logarithmic_scale

https://en.wikipedia.org/wiki/Amplitude

https://en.wikipedia.org/wiki/Seismic_wave

https://en.wikipedia.org/wiki/Seismometer

https://en.wikipedia.org/wiki/Richter_magnitude_scale

Risk evaluation of Earth Quake


Earth Quake Zones of India



Following the March 2011 Fukushima Daiichi nuclear plant accident in Japan, DOE embarked upon several initiatives to investigate the safety posture of its nuclear facilities relative to beyond design basis events

(BDBEs). These initiatives included issuing • Safety Bulletin 2011-01, Events Beyond Design Safety Basis Analysis• Review

of Requirements and Capabilities for Analyzing and Responding to BDBEs,

• , OE-1: 2013-01, Improving Department of Energy Capabilities for Mitigating Beyond Design Basis Events.

• Protocol for Enhanced Evaluations of Beyond Design Basis Events Supporting Implementation of Operating Experience

Final case : Beyond Design Basis Fukushima Daiichi Nuclear plant accident in Japan

BEYOND DESIGN BASIS EVENTS

http://energy.gov/ehss/downloads/does-safety-bulletin-no-2011-01-events-beyond-design-safety-basis-analysis-march-2011



http://energy.gov/ehss/downloads/review-requirements-and-capabilities-analyzing-and-responding-beyond-design-basis




http://energy.gov/ehss/downloads/improving-department-energy-capabilities-mitigating-beyond-design-basis-events

http://energy.gov/ehss/downloads/improving-department-energy-capabilities-mitigating-beyond-design-basis-events

http://energy.gov/ehss/downloads/protocol-enhanced-evaluations-beyond-design-basis-events-supporting-implementation




Solutions to avoid Design Basis Pit-falls

1.Design Basis Review : Review by owner and Designer during 0 % , 30% and 60% completion of project , based on Risk factors.

2. Beyond Design Basis or Design Basis Accident : Think beyond Design Basis and be prepared

3. Hire professional Engineering Company : Appoint GES contractor for Design Basis documentation.

4. Data collection: Monte Carlo method or frequent samples


Design for Design Basis Threat

Courtesy “ DOE


HAZOP HAZID

PHR

PSM

Next to mitigate risk?

Right Design basis !

Key to Right Design Basis ! • Regular Review by owner

and Designer • Confirmation by accurate

Data.• Communication and

Documenting changes.


Thanks !

Some References 1.A Design Basis accident (DBA) or maximum credible accident (MCA) is a postulated accident that a nuclear facility must be designed and built to withstand without loss to the systems, structures, and components necessary to assure public health and safety.

2. Monte Calro analysis Monte Carlo simulation, or probability simulation, is a technique used to understand the impact of risk and uncertainty in financial, project management, cost, and other forecasting models.

3. Design Basis : Set of conditions, needs, and requirements taken into account in designing a facility or product.4. As per GSA (USA). The Basis Of Design (BOD) describes the technical approach planned for the project as well as the design parameters to be used. The BOD is typically developed in technical terms, whereas the owner’s project requirements are developed by GSA in concert with the customer agency and are expressed in layman’s terms.


http://www.businessdictionary.com/definition/condition.html

http://www.businessdictionary.com/definition/need.html

http://www.businessdictionary.com/definition/requirements.html

http://www.businessdictionary.com/definition/account.html

http://www.businessdictionary.com/definition/facility.html

http://www.businessdictionary.com/definition/product.html


References and Abbreviations • MOC- Management of Change • PSM- process safety management • PHR – Process Hazard review • PHA- Process Hazard Analysis • HAZOP- Hazard and operability review • HAZID – Hazard identification • DBA – Design Basis Accident • GSA – Geographical Society of America• BDBE- Beyond Design Basis Events.• DOE- Department of Energy (USA)