(129b) Leveraging Historical Risk Wisdom for Projects: Yes It Can Really Occur

The concept of leveraging the knowledge and prior work in the petrochemical industry, as well as all industries, is not new. The idea is so common that most people believe it simply occurs. Just like many other “good sounding concepts”, it is stated much more often than it is performed. Using the work of others requires effort – including validation of previous results and an execution plan to leverage the “prior wisdom”. However, turning the platitude “don’t reinvent the wheel” into a reality, does have a tangible impact on the design flexibility, cost and, more importantly, safety of a project.

Major capital projects either modify an existing facility or construct a new facility with existing technology. The key word is existing. Capital projects do not “discover” new technology, and they rarely “discover” new risks. Rather, large capital projects use known technology, and the knowns include known risks and effective mitigations. Surprisingly, leveraging previous risk analyses (ex: PHAs, LOPAs, QRAs, etc) to inform and improve the design of a new or modified facility at a comprehensive level is rarely performed.

Over the past few years, Chevron Phillips Chemical (CP Chem) has engineered multiple world-scale petrochemical facilities. JGC performed the Front End Engineering Design (FEED) and Engineering, Procurement, and Construction (EPC) for several of these facilities and teamed up with Trinity Consultants for the Process Hazard Analysis (PHA). The three stakeholders, CP Chem, JGC, and Trinity, developed a PHA methodology to leverage the comprehensive risk knowledge of nearly all other existing CP Chem facilities and personnel. The methodology included a multi-phase approach to match the different stages of the engineering design. This may sound trivial; however, risk experts recognize the complexity of this task. We will provide the “how” of the methodology: it is not simply an idea – these projects made it a practice.

To begin, in order to make this approach into a method, we will answer the following questions:

1. How do you know previous PHAs are correct?
2. How can you “right size” the risks and associated mitigations for new & much larger facilities?
3. Are the risks different for large facilities vs. smaller ones?
4. No two designs are ever the same—how to you make sure you don’t miss risks buried in the details?

The benefits to the method fall into three categories:

1. Increased Quality & Comprehensiveness of Risk Identification: The PHA method utilized other PHAs to ensure the expertise & knowledge of personnel of all facilities was leveraged. This allows other subject matter experts to weigh in on the PHA without having to be present by using past knowledge and expertise, yet still allowing for brainstorming.
2. Increased Design Flexibility: The PHA methodology allowed for early identification of high-risk scenarios, and allowed their associated complex and potentially expensive mitigations (ex: inherently safer design, safety instrumented systems, complex interlocks, and unique relief system designs) to be selected early. In later stages of engineering the flexibility is limited, due to progress of design or limitations of budget. Identification of these potential risks and mitigations allow for more accurate project cost estimation and reduces engineering design rework when a late-stage design change is identified due to a late-stage risk being identified..
3. Efficiency: The identification of the known risks and associated mitigations did not require a comprehensive HAZOP / LOPA at a time when the documentation simply was not available to perform such an evaluation. This allowed the project team to spend more in-depth time discussing difficult scenarios and how they might be mitigated earlier in the process. The final and comprehensive HAZOP / LOPA was performed at the end of the design, and the PHA project lifecycle methodology ensured “no surprises” were discovered during the final evaluation.

The paper will support the conclusions with data including:

• Quantity of safeguards/IPLs during the different phases of the project (i.e. different phases of the project PHA project lifecycle)
• Comparison of safeguards/IPLs across different facilities, including the other recent world scale projects
• Examples of project design flexibility for high risk and complex scenarios with details of identifying safeguards / IPLs at different project stages.