A turnaround is the process of shutting down one or more units of a facility, in this case a refinery, to perform scheduled maintenance and inspections. In 2020, Assistu Engineering provided engineering services to one of the largest turnarounds our client had to plan for and perform. The main units that were shutdown consisted of the Fluid Catalytic Cracker (FCC), Sulfur Recovery Unit (SRU) and the Splitter. Based on previous turnarounds, the bottleneck originated from the engineering group delaying progress due to repair and mitigation decisions taking time to evaluate. The client knew that support was needed. They also knew that engineers with the suitable skills and experience were needed to quickly identify issues and provide solutions without holding up other activities performed in the facility.
The simplest part of a turnaround is addressing and planning for known issues. However, the challenge of this process is the flaws and defects that are unplanned which are uncovered during inspections and non-destructive examinations (NDE). Once this is reported to the inspection team, each flaw must be evaluated, and a solution must be promptly decided upon and implemented. Sometimes, the solution is as simple as a blend grind of a linear indication or performing a weld metal buildup repair. Sometimes further NDE is required to acquire further information or more data. Whichever the next steps, if the repair, replacement, or inspection is too complicated, costly, or time-consuming, then another solution must be formulated. No matter the complexity of a problem, the expertise of Assistu’s engineers can result in a smoother turnaround. Below are two different examples of complex decisions that need to be made during this turnaround, and how they benefitted the client:
A 100% IRIS tubular inspection was performed on a fin fan heat exchanger. In the last turnaround the exchanger was replaced and the baseline inspection, conducted 4 years ago, reported no metal loss or flaws of any kind. In this turnaround, the tubular inspection reported over 30% of its tubes containing more than 50% metal loss. Based on the short-term corrosion rate, 26% of the tubes would need to be plugged to have a remaining life of 4 years to reach the next turnaround cycle. Based on conversations with the process engineers only 12% of the tubes can be plugged without significantly impacting the efficiency of the system. After running several scenarios, it was decided to plug 10% of the tubes and plan to install a new fin fan in 3 years, piggybacking on another outage. This ultimately allowed the client to safely run the fin fan and saved from immediate replacement costs and turnaround time delays.
The client had their own procedure for evaluating gasket seating surfaces (GSS). A number of found work scopes were submitted to address these due to the inexperience of the inspectors and their unfamiliarity with the client’s standard. We were tasked to review these work scopes. Although this was a simple task of determining if they should be executed, the number of work scopes submitted was upwards of a few dozen, and most provided insufficient information. This involved back and forth inquiries as well as physically viewing the GSS in the plant. In the end, out of all of the reviewed work scopes roughly 90% were rejected (this means no GSS repair required) which saved the client many hours of work avoiding an extension to an already long turnaround.
This discovery work can be an overwhelming burden on the already time-constrained team at the plant. This is where Assistu’s services come into play.
Assistu Engineering was requested to provide on-site engineering support for a 2-month duration. The scope of work included:
- development and implementation of key flow processes for review, revision, and approval of work scopes,
- preparation of repair work scopes,
- preparation of investigative inspection work scopes,
- troubleshoot fit-up issues,
- management reporting of major repairs and substantial scope increases,
- welding specification procedure reviews,
- and other tasks that help relieve the burden of the core turnaround team.
The turnaround successfully ended in March 2020, just prior to the COVID-19 lockdown. Assistu contributed to meeting the turnaround deadline and provided engineering expertise which resulted in a successful turnaround and a satisfied client.
Contact us today for a consultation to see what kind of support we can offer you during your facility turnaround.