Becht Production Assurance, Operating Modes Assessment

With contributing authors Stephen DeLude and Bruce Scott.  

It can be said that any project is judged on three principal outcomes:

1. On budget
2. Completed onschedule and
3. Operates and produces product as expected.

During the early development phases of a new industrial plant, the main focus is to develop a steady state case with consideration of plant upsets, startups and shutdowns. There are also commercial assessments to understand the local industry infrastructure such as feedstock and product pipelines, rail and shipping facilities, power, natural gas and water supplies. Based on industry reliability data and maintainability requirements, the high-level philosophies on the sparing of units, equipment and tankage are then established. All these considerations play a key role in site planning and environmental permitting.

Operating Modes Assessment

As part of Becht’s recently established Production Assurance requirements, Becht has created a work practice to review the entire range of operating modes of a new plant.  These Operating Modes Assessments (OMA) enable the operating and project design teams to fully validate the design requirements that will support the integrated operation of the complex during all phases of the project. The timing of this review is important and is usually completed in FEL 2 or before detailed design gets underway.

It is often found that design teams have been operating in separate “silos” and have not considered the integrated operation of the plant – especially during unusual operating modes including start-ups, shutdowns and process upsets. A significant side benefit of the OMA work practice is the improved understanding of the interactions between the various unit operations so the design teams can generate a clear and coherent view of the design intent for the fully integrated operation.

An OMA is essentially a 1–2-week workshop facilitated and supported by Becht SMEs and sponsored by a senior operations leader assigned to the project. It is essentially a cold eyes review of the project’s operations, maintenance, technical and process design definition includes technology licensor support as needed.

Deliverables

The OMA is specifically targeted to identify gaps in design requirement, feed and intermediate management, unit interfaces, and overall utility demands.

The key deliverables from the operating modes review are:

• A risk-based threat register with mitigative steps identified where possible (refer the sample Figure 1 below)
• An understanding of major area interfaces and project phases
• Agreement on the enabled operating modes for the plant
• Alignment on utility requirements to support all identified operating modes (including start-ups and shutdowns)
• Required isolation to enable the various agreed operating modes
• Establish length of time an operating mode can be supported (which may be dependent on inventory available)
• Provide high level input toward developing turnaround scenarios and upset recovery plans
• Identify key design vulnerabilities for full understanding of any risks or opportunities for mitigation

Figure 1: Sample Threat Register

Information Requirements:

The overall tools, documents and information that are required well in advance of conducting a workshop:

• Process design basis
• Operating/turnaround philosophies
• Block flow diagram, process flow diagrams, utility system diagrams
• Unit sizing basis, if available
• Construction phasing
• Client risk register and premises
• Threat register and scoring premises
• Definition of OM review boundaries
• OM prioritized list
• OM spreadsheet tabulation for each operating mode discussion
• Admin, IT and project management support for workshop scheduling, meeting room logistics (Wi-Fi, project database access), attendee list, data gathering, and workshop facilitation.

Operating Modes Assessment Work Process

Depending on the complexity of the industrial plant and client requirements, Becht has documented two OMA practices.

The following is a high-level overview of the work process that can be used for a complex project OMA:

• Provide a list of prioritized information needed based on a plant process design basis.
• Establish a threat register, risk matrix premises, a list of prioritized OM’s and obtained agreement with the client.
• Review the design documents with a focus on integrated operation.
• Identify the plant’s priority (limiting cases) OM’s and transitions (usually in the range of 30 to 50 modes versus the 500+ that would be the theoretical number of independent modes given all permutations and combinations of operating conditions). The priority OM’s and the work process are reviewed internally and then confirmed with the client.
• Discuss the operating conditions for the prioritized list of OM’s and review the transitions between OM’s. This provides a full and shared common understanding of plant capabilities/constraints under an integrated operation.
• Develop a matrix to provide a clear picture of modes that were fully enabled and to identify the potential areas of vulnerability or opportunity for further follow-up.
• Document and present the key operating philosophies and/or premises, key risks/threats/opportunities, and potential recommendations and options.

Typical Findings

An OM review can have several key findings and even follow a similar pattern of plant deficiencies identified in other OM reviews;

• Utility equipment sparing and sizing are inadequate.
• The commissioning sequence and duration are poorly understood. The utilities and purging medium volumes required for commissioning are underestimated or inadequately sourced.
• The project construction plan is not focused on prioritizing and completing the construction of systems versus completing the building of the entire unit.
• Intermediate storage is inadequate for a plant turnaround or for a unit trip. The storage requirements for de-inventorying the units and flushing the units are often underestimated.
• The project design and operations team lack an understanding of system interdependencies.

Becht has a core team of specialists and advisors with capital projects production assurance experience that can help initiate discussions and frame the requirements for your OMA. CLICK HERE for more information.