Hydrocarbon Processing - February 2022 - 79

Water Management
B. ALLEN, Pace Solutions, Calgary, Alberta, Canada
Upkeep down the pipe: Plant shutdowns
and water treatment
The maintenance checklist for a plant shutdown can sometimes
look intimidating and, in the face of a short timeline, unnerving.
For aging facilities, every year the maintenance checklist
becomes more extensive and completion becomes more
difficult. As staff faces greater challenges, bringing in specialists
to help complete certain tasks is almost imperative. All facilities
require water to operate, and a water treatment specialist
should be one of the first outside contractors to be introduced
to the shutdown team (FIG. 1).
Inevitably, once maintenance has begun, other issues and
concerns can arise. When it comes to the water system (steam
boilers, cooling towers, pre-treatment systems, etc.), these issues
must always be addressed immediately to maintain production
and avoid costly damage to equipment. Waiting to call
a water treatment specialist only during emergencies can be expensive.
A water treatment-related emergency can raise the cost
of service calls by 2-3 times, garner a premium for parts and
cause unscheduled downtime. Shutdown procedures should
help prevent these inflated expenses. Having a scheduled water
treatment specialist integrated into the plant shutdown plan
shortens the maintenance checklist so internal staff can focus
on other things. It also promotes faster and safer diagnoses and
resolutions that mitigate costly unscheduled downtime.
Water system issues are not always what they seem.
In the face of increased corrosion, heavy deposition, scale, microbiological
fouling and system leaks, operators often ask, " If
a system was working fine for years, what changed? " Reasons
can include:
1. Higher dissolved oxygen content in the treated water
2. Changes in feedwater chemistry
3. Mineral or microbiological content and concentration
4. Aging or faulty equipment (seals, pipes and valves)
5. Greater demands on the system due to weather
or increased production.
These causes start affecting the system through biofilm
growth, corrosion, scale and accumulating deposits. Generally
controlled by water treatment products, changes in feedwater
or system conditions can throw off the ratios of treatment
products, rendering them less effective. Not only does this affect
system health, but it also greatly reduces system efficiency.
Why would feedwater quality change? Climate change has
proven to have drastic effects on water quality, particularly in
times of reduced snowpack. Upstream issues, such as industrial
monoculture farming and mining/quarrying can increase
FIG. 1. The water treatment team focuses on details in every
component of the water system.
Hydrocarbon Processing | FEBRUARY 2022 79
sediment levels, mineral constituents and chemical content.
Changes in water sources, such as moving from surface water to
deep aquifers, will result in drastic changes in water chemistry
and quality. Lighter permitting standards and loosened wastewater
runoff regulations can also impact the water table for surrounding
communities.
Keeping on schedule. Merely relying on accrued work orders
to determine the maintenance checklist is an effective way to
discover issues that throw the schedule off by days, even weeks.
Thorough inspections by outside professionals several weeks
before a scheduled production break can introduce new eyes for
inspection purposes, help in planning the full scope of the shutdown,
inform proper part orders and reduce the total downtime.
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