By Lev Serebrinsky
Experience with achieving 100% Mechanical Reliability of Refinery Bad Actor Heat Exchangers shows that this was achieved by development and introduction of highly specific, many-faceted programs.
This article presents a methodology for instituting a Heat Exchanger Bad Actor Resolution Program. The first step of the methodology is the official kick-off of a Bad Actor Heat Exchangers Resolution Program (we are using a generic name here). However, a certain precondition for the success of the methodology must be in place. That is, the Organization must be ready to dedicate a heavy involvement of many mechanical, technical, and operations specialists in the Program's three parallel, never ending activities as follows:
The Program is based on the following four principles:
Since the full implementation of these fundamental principles makes the diffgerence between the Program's failure and success, the following summarizes some experience with the implementation of Principles #3 and #4.
Principle #3: At a large refinery, the Steward's assignment must be their full-time job; at a small refinery the Steward's job could be at least a three year special assignment. There is no exception to this rule: all failed Programs did not have a full-time Steward, but all successful Programs have a full-time Steward to this day.
Principle #4a: In no case should the Steward develop and prioritize the Bad Actors list alone. The Steward compiles a draft list by soliciting input during personal interviews with process, maintenance, inspection, and technical personnel on each process unit. These interviews are a time consuming and scrupulous process which must be based on a Bad Actors questionnaire which, in turn, is developed by the Steward. The questionnaire reflects the Organization's approved Bad Actor heat exchanger criteria (e.g., the number of unscheduled outages, maintenance costs, lost opportunity costs, or all the above plus whatever else the Organization wants to steward).
Further, the final number of Bad Actors must not exceed 6% of the refinery total count of its shells. If the number is higher, the Bad Actors criteria are either too many, or too loose, or both, and must be reconsidered. There is no exception to the "maximum 6%" rule: several large refineries foiled their Programs solely because their Bad Actors lists were so large that they made the implementation of the Program totally unrealistic.
The list, furthermore, must have several columns such as resolution priority, problem mode(s), problem root cause, lost opportunity costs, etc., and when the final draft is ready, each Bad Actor must get its resolution priority. The "A" priority shall be given solely to those Bad Actors which are scheduled to be opened at the process unit's major turnaround within the next two years. All other Bad Actors receive "B" or "C" resolution priorities at the Steward's discretion.
Upon releasing a resolution recommendation on any "A" priority Bad Actor, the Steward removes it from the Bad Actors list conditionally (until the recommendation is implemented and proven correct by operations one year afterwards). Meanwhile, the Steward moves the nearest "B" priority Bad Actor into the "A" group, and the cycle repeats itself.
Principle #4b: Since all resolution recommendations will require re-engineering the existing Bad Actors, their follow-up takes the Bad Actor out of service. The overwhelming experience shows that the best time to implement the recommendation is during the process unit turnaround when all Bad Actors at the given process unit are budgeted for pulling and shipping anyway. This approach has proven to be so time and cost-effective that we consider it to be the key to the fast resolution of Bad Actors.
Principle #4d: The Program Stewardship Report must report the status of the #2a and #2b goals, plus the overall refinery trend of annual heat exchanger maintenance costs during the past four years, plus any other criteria selected by the management. Note, that many seeming criteria (e.g., the number of Bad Actors in the list) were dropped from data gathering after the first stewardship report since, contrary to the original expectations, they either said nothing to anyone or were simply misleading.
In conclusion, the successful Bad Actor heat exchangers programs delivered some amazing findings and results. These are summarized as follows:
The most visible and important results of the Programs are as follows:
From its third year, refineries have not had a single process unit downtime caused by heat exchangers. Compare this to the well known fact that heat exchangers are the second leading cause of refinery downtime worldwide, and by the fourth year, the overall heat exchanger maintenance costs at these refineries was gradually reduced to 60% of their pre-program years. These are still about 1/3 less than current costs at comparable refineries that have not implemented any Program at all.