Pre-commissioning is a critical phase in any oil and gas project. It bridges the gap between construction completion and full commissioning, ensuring that every system, subsystem, and component is verified before hydrocarbons or process fluids are introduced. A structured pre-commissioning checklist reduces the risk of costly delays, safety incidents, and equipment damage during startup. This guide provides a thorough checklist framework that oil and gas teams can adapt to their specific facility requirements.
Why Pre-Commissioning Matters
The pre-commissioning phase is where construction quality is put to the test. Skipping or rushing this phase has led to some of the most expensive project overruns in the industry. A rigorous pre-commissioning process confirms that all installed systems meet design specifications, that safety systems are functional, and that the facility is ready for the introduction of live process media. Regulatory bodies such as OSHA, the EPA, and international standards like IEC 61511 mandate documented evidence that systems have been verified before startup. Without a structured checklist, teams risk overlooking critical checks that could lead to leaks, equipment failures, or hazardous conditions.
Piping System Checks
Piping systems form the arteries of any oil and gas facility. Pre-commissioning of piping ensures that all connections are secure, materials are correct, and the system can safely contain process fluids at operating pressures and temperatures.
- Verify pipe material, grade, and schedule against isometric drawings and material specifications
- Confirm all welds have been inspected and accepted per the approved welding procedure specification (WPS)
- Perform hydrostatic or pneumatic pressure testing at the specified test pressure and hold duration
- Check all flanged connections for correct gasket type, bolt torquing, and alignment
- Flush piping systems to remove construction debris, weld slag, and foreign materials
Mechanical Equipment Verification
Rotating and static mechanical equipment must be inspected and tested prior to commissioning to ensure reliability and safety during operation.
- Confirm equipment nameplate data matches the equipment datasheet and purchase order specifications
- Verify shaft alignment for rotating equipment such as pumps, compressors, and turbines
- Check lubrication systems including oil levels, grease points, and oil mist systems
- Perform solo runs (uncoupled) for motors and drivers to verify rotation direction and vibration levels
- Inspect pressure relief devices for correct set pressure and verify calibration certificates
Electrical System Checks
Electrical systems power every aspect of the facility. Pre-commissioning ensures safe energization and reliable operation of all electrical components from high-voltage switchgear to field instruments.
- Perform insulation resistance (megger) testing on all cables before energization
- Verify cable routing, labeling, and termination against cable schedules and wiring diagrams
- Test protective relay settings and confirm trip logic for circuit breakers and motor starters
- Check earthing and bonding connections and measure earth resistance values
- Verify UPS and emergency power systems including battery bank capacity testing
Instrumentation and Control Systems
Instrumentation provides the eyes and ears of the facility. Proper pre-commissioning of instruments and control systems is essential for safe and efficient operation.
- Perform loop checks to verify signal continuity from field instruments through to the DCS or PLC
- Calibrate all instruments against certified reference standards and document calibration results
- Test safety instrumented systems (SIS) including emergency shutdown (ESD) sequences
- Verify control valve stroking, seating, and positioner calibration
- Confirm fire and gas detection system functionality including detector coverage and alarm setpoints
Civil and Structural Checks
The foundation and structural elements of the facility must be verified to confirm they can support operational loads and environmental conditions.
- Inspect concrete foundations for cracks, spalling, or defects and verify anchor bolt torquing
- Check structural steel connections, bolt tightness, and protective coating integrity
- Verify fireproofing coverage and thickness on critical structural members
- Confirm drainage systems are clear and slope gradients are correct for containment areas
Safety Systems and Emergency Equipment
Safety systems are the last line of defense. They must be fully functional and tested before any process media is introduced to the facility.
- Test emergency shutdown (ESD) system logic and confirm valve closure times meet specifications
- Verify fire suppression systems including deluge, sprinkler, and foam systems are charged and operational
- Confirm emergency lighting, PA systems, and evacuation alarm functionality
- Inspect safety showers, eyewash stations, and first aid equipment for accessibility and operability
- Verify wind socks, H2S monitors, and area gas detectors are correctly positioned and calibrated
Documentation and Turnover Packages
Complete and accurate documentation is the foundation of a successful commissioning and handover process. All pre-commissioning records must be compiled into turnover packages.
- Compile all completed ITRs, test records, and punch list items into system turnover packages
- Verify that all as-built drawings are updated to reflect field modifications
- Confirm vendor documentation, operation manuals, and spare parts lists are available
- Ensure all punch list items are categorized, tracked, and closed out before system turnover
Best Practices
- Begin pre-commissioning planning during the detailed engineering phase, not at the end of construction
- Assign dedicated pre-commissioning engineers for each discipline to maintain accountability
- Use digital checklist tools to capture real-time data, photos, and sign-offs in the field
- Conduct daily pre-commissioning progress meetings to identify and resolve issues quickly
- Maintain a centralized punch list system with clear ownership and target closure dates
- Integrate pre-commissioning milestones into the overall project schedule to avoid conflicts with construction activities
How Checksheets Helps
Checksheets provides a purpose-built digital platform for managing oil and gas pre-commissioning checklists. Teams can create discipline-specific checklist templates, assign them to systems and subsystems, and track completion in real time from any device. The platform supports photo attachments, digital signatures, and automated punch list generation, ensuring that nothing is overlooked. With built-in reporting dashboards, project managers gain instant visibility into pre-commissioning progress across the entire facility. Checksheets eliminates the paperwork burden so your team can focus on what matters most: getting the facility safely and efficiently to first oil or first gas.