The daily records of oil and gas recovery equipment are typically kept on a shift or daily basis, scattered among inspection forms and operation logs. It's challenging to determine whether the equipment status is improving or deteriorating based solely on a single day's records; only when the data from a month is aggregated using a consistent approach can trends become apparent. The aggregation itself is not difficult; the challenge lies in ensuring consistency in approach and maintaining consistency over time.
Unify the narrative before summarizing
Inconsistency in data caliber is the most common obstacle in monthly summaries: some teams record start-stop times, while others record operating durations; some measure the amount of recovered liquid by tank, while others by pump. When data with inconsistent caliber are put together, the resulting summary is not comparable.
The approach to unifying the criteria involves clearly specifying each item to be recorded: unit of measurement, timing of statistics, and calculation method. For instance, the operational duration is explicitly defined as "cumulative operating hours on the current day", while the recovered liquid volume is specified as "cumulative recovery volume for the month compared to the solvent input for the same month". Once the criteria are set, they should not be altered midway. If changes are indeed necessary, the switchover time should be indicated on the summary sheet.
What items should be recorded in the monthly summary sheet
| data category | Statistical Project | Consolidated scope |
|---|---|---|
| Status category | Temperature, pressure difference, and operation duration of each section | Accumulate by day, average by month |
| Output category | Recovered liquid volume, solvent input volume | Calculate the monthly cumulative ratio for the current month |
| Event type | Alarm frequency, maintenance, and replacement records | Record each time, specifying the date |
| Comparison item | Compared with the average value of the previous three months | Highlight changes that exceed the set range |
| Re-check items | Review conclusion of projects exceeding the threshold | Indicate the reason for judgment and subsequent arrangements |
| Archive item | The monthly statements are bound by year | When changing the caliber, indicate the switching time |
These items can be categorized into three types: status types (temperature, pressure difference, operation duration), output types (recovered liquid volume, recovery rate), and event types (alarms, maintenance, consumable replacement). Status types reflect the health of the equipment, output types indicate the recovery effect, and event types explain the reasons for data fluctuations. Only by looking at these three types together can we connect the dots between "data changes" and "why they change".
How to interpret trends
{IMG}The key to interpreting trends lies in examining the rate of change, rather than merely focusing on the absolute value. Although the absolute decrease in the amount of recovered liquid from 3 tons to 2.8 tons may not seem significant, if the solvent input remains unchanged, a continuous downward trend over three consecutive months constitutes a clear indication. Comparing the data of the current month with the average of the previous three months provides a more effective filter for occasional fluctuations than comparing it month-on-month.
When interpreting, overlay the event-based records: If the pressure difference increases in a certain month, and heat exchange surface cleaning was performed during that month, and the pressure difference decreases after cleaning, it indicates that the cleaning was effective; if it does not decrease after cleaning, the cause needs to be re-evaluated. Without the comparison of event records, trend interpretation can easily become guesswork.
How to set the threshold for abnormal signals
Another use of aggregation is to set simple warning lines. Warning lines are not set based on intuition, but are derived from historical data: using the normal fluctuation range over the past several months as a benchmark, and focusing on re-checking months that exceed this range. The threshold should be set generously, preferring to conduct multiple re-checks rather than losing trust due to frequent false alarms.
After the threshold is triggered, don't rush to draw conclusions. First, verify the details and event records to confirm that it is not a metering issue or maintenance impact. Then, determine whether it is due to a change in equipment status.
Frequency and retention of aggregation
- Summarize the data of the previous month on a fixed date each month to form a monthly operation data sheet;
- Compared with the average value over the past three months, highlight the items with significant changes;
- Mark the maintenance, cleaning, and replacement events of the current month on the table;
- Conduct a review of projects exceeding the threshold and state the review conclusion clearly;
- The monthly reports are archived annually and serve as a part of the equipment status archives.
Frequently Asked Questions
Can monthly summaries still be made if the daily records are incomplete?
You can summarize first, but you need to indicate the missing days and their possible impacts on the table. A better approach is to deduce the items that need to be added to the daily records based on the gaps revealed by the summary, and gradually complete the daily records.
Should the recovery rate be calculated on a monthly or quarterly basis?
Observe trends on a monthly basis and assess levels on a quarterly basis. Monthly data may fluctuate due to inventory and feeding schedules, while quarterly averages can better reflect the true recycling level of equipment. It is advisable to consider both perspectives.
How detailed should the summary table be?
Limited to what can support trend judgment. Too many projects will increase the reporting burden, making it difficult to persist; too few projects will not reveal any issues. A few items each for status, output, and events are sufficient.
This article is compiled by Luoyang Wohong Petrochemical Equipment Co., Ltd. The company provides design and manufacturing, skid-mounted customization, installation and commissioning, as well as after-sales operation and maintenance services for three-time oil and gas recovery equipment to gas stations and oil depots. If you need on-site inspection or scheme configuration, please feel free to contact us for discussion.