A turnaround of process plant is a planned activity where entire or a major portion is taken off-stream. It is basically a planned shutdown at a larger scale and for an extended duration. Usually, the turnaround is planned every two to four years.
During the turnaround, production of the plant is stopped or very greatly reduced. Revenue is stopped or nearly stopped during this period.
Here the focus of this article would be turnarounds in the oil and gas sector. These include refineries, petrochemicals, gas plants, etc.
Turnarounds are very complicated, requiring robust planning, resource-intensive, involving high cost and having a very high risk.
Reason for Turnarounds
After running over a certain period of time, the process plants need maintenance, which is basically preventive in nature. It also needs renovation, upgrade, inspection & testing, debottlenecking, etc. Hence, at a regular interval, turnarounds are planned to carry out the activities as stated earlier. These turnarounds give a new lease of life to process plants. It also provides an opportunity to fix many issues. In short, turnarounds are very important to keep running the process plants.
Activities Performed During Turnarounds
A wide range of activities is performed during the turnarounds. The major and important activities are listed hereunder though there are many minor ones over and above:
- Inspection for corrosion of equipment and piping
- Inspection for integrity and wear of equipment
- Inspection for integrity of piping
- Inspection for integrity of electrical system
- Installation or replacement of worn-out parts/equipment
- Replacement of catalyst
- Replenishment of chemicals
- Installation of new equipment
- Modification works
- Debottlenecking works
- Upgrade in equipment
- Renovation workh
All the departments of the process plant are involved in some way or the other in the turnarounds. The production is involved in de-commissioning and re-commissioning of the plant. The maintenance is involved during the turnaround for multiple activities that form the part of routine maintenance. Inspection and testing are done by the inspection department. Project implements upgrades, revamps, etc. Procurement is responsible to make available all the materials required. Various contractors are lined up by contract departments.
Safety, health and environmental aspects are taken care by the HSE department. Planning departments plan and monitor the overall turnaround.
Apart from the internal ones, various external stakeholders are involved. These are the contractors, sub-contractors, vendors, service provides, suppliers, etc.
Turnover starts with de-commissioning of the plant. As part of the de-commissioning, the plant is made process fluid free. This is done by draining, venting, nitrogen or steam purging. Once, the process fluid is removed, then the test is carried out to check the same.
Upon process fluid freeing, the real activities of turnaround starts. They include, inspection, replacement of defective, worn-out items, routine maintenance, replenishment of chemicals and other fluids, changing of catalyst, re-calibration etc.
Apart from the above-mentioned activities, there may be small projects like installation of new or upgraded equipment, debottlenecking, renovation etc.
Upon the completion of the activities both planned and unplanned, the plant is re-commissioned. This starts with oxygen purging or intertization and ends when the plant operation is stabilized.
Turnarounds are generally spread over four weeks.
Proper planning is key to success of any turnaround. Usually, the planning process starts at least a year before the start date of the turnaround. Generally, a task force or a dedicated team is formed one year ahead and includes the planning department representative and headed by a senior management person. Various activities take place during this time.
Planning activities include the following:
- Formation of Turnaround Implementation Team
- Defining the turnaround scope of work
- Firming up the turnaround scope of work
- Establish pre-turnaround work
- Establishing or updating various related procedure
- Establishing or updating the communication protocol
- Establishing or updating the RACI Matrix
- Establishing contracting and procurement strategies
- Lining of the contractors, including the maintenance, inspection, manpower, equipment, etc.
- Processing the purchase orders
- Risk analysis
- Relevant training to the workforce
- Preparation of turnaround schedule
- Turnaround close-out procedure
- Finalization of reporting system
Planning, Monitoring and Reporting During Turnaround
During turnaround the work start as per the schedule. As part of monitoring, it is ensured that there is proper coordination. All the materials and services are made ready and assign the activities. They do the activities as planned. However, there is a provision of unscheduled works and surprises in a good schedule, as all turnarounds invariably throw around surprises.
A good reporting system is established with various frequencies and levels of details as part of the communication and control process.
Risk in Procurement
As any other activity and projects in oil and gas sector, turnaround is also full of risk. This itself is very complicated with lot of uncertainties, which is further topped up with risks. The major risk includes the following:
- Schedule overrun
- Cost overrun
- Unexpected need of modification/ repair
- Failures during de-commissioning and re-commissioning
In summary, a turnaround of process plant, especially in oil and gas sector is very complex. It is full of uncertainties and risks. A very good plan is required for their success.