Building inside an operating refinery is different from building on an empty plot. The construction area borders live process units. Tie-ins connect new pipe to systems full of hydrocarbons. Refinery operations, the owner’s project team, the EPC contractor, licensors, vendors and subcontractors all have a say. Most of the problems on these projects happen at the boundaries between them. Managing construction interfaces in refinery projects is largely about handling those boundaries deliberately instead of discovering them in the field.
What is a construction interface?
A construction interface is any point where the work, responsibility or physical systems of one party meet those of another. In refinery projects, interfaces fall into three groups: physical, organizational and operational.
Physical interfaces
- Tie-ins between new and existing piping, electrical and control systems
- Battery limits between project scope and the existing plant
- Shared infrastructure such as pipe racks, roads, drains, utilities and control rooms
- Underground services in congested and often poorly documented ground
Every tie-in belongs on a tie-in list, marked on the P&IDs, verified in the field and classified by when it can be made: during normal operation using methods such as hot tapping, during a planned shutdown, or during a turnaround.
Organizational interfaces
| Party | Typical interface issues |
|---|---|
| Refinery operations | Permits, isolations, access to live areas, operating constraints |
| Owner’s project team | Approvals, design reviews, change decisions |
| EPC contractor | Overall execution and coordination |
| Process licensor | Design requirements and approval of deviations |
| Vendors | Package interfaces and site support |
| Subcontractors | Scope boundaries and sequencing |
Operational interfaces and SIMOPS
Construction next to running units means simultaneous operations, or SIMOPS. A SIMOPS plan defines which activities can proceed together, under what controls, and who can stop work. Hot work near a live unit may be restricted while the unit is draining, sampling or starting up, for example. Construction crews also need to be part of the refinery’s gas detection, alarm and muster arrangements, not running a separate system.
Tools for managing interfaces
- Interface register: every interface, its owners on both sides, the information needed, the need date and status
- Tie-in packages: one complete pack per tie-in with drawings, isolation plan, materials, procedure and permits
- Interface meetings with operations: held regularly, not only inside the project team
- Shutdown alignment: tie-ins that need a shutdown fed into the refinery’s shutdown plan early
- An operations liaison: one named point of contact between the project and the operating units
Why tie-ins fail
- Existing conditions differ from the drawings because field verification was skipped
- Tie-in materials are not on site when the shutdown window opens
- Isolation valves are unavailable or passing
- Tie-in scope is added late to a turnaround that has already been frozen
Missing a tie-in window can hold up a project until the next available shutdown, which may be a long way off. That is why tie-in readiness deserves its own tracking.
Related topics
Shutdown pressures are explained in what makes refinery turnarounds operationally complex. Discipline sequencing inside the construction area is covered in coordinating civil, mechanical, electrical and instrumentation work, and design-side causes of tie-in problems in how design coordination reduces rework.
Apex Core Engineering supports refinery work through construction management and project support services, including coordination of site activities in operating plants. For the wider range of support petrochemical and refining owners use, see engineering and workforce support for petrochemical plants.
Frequently asked questions
What is a hot tap?
A method of connecting to a pipe or vessel while it stays in service, using specialist equipment and strict procedures.
What does SIMOPS mean?
Simultaneous operations: activities by different parties in the same area at the same time, such as construction next to operating units.
Who controls permits in an operating refinery?
Normally the refinery’s operations team, which keeps authority over its live units. Project permits are coordinated through it.
Discuss construction support for your refinery project with Apex Core Engineering.