Published on 18 Apr 2018 by Emma Leoni
This document is to describe the sparing and tooling requirements for the manufacture, testing, installation, pre-commissioning, commissioning and operation of the field development, for the subsea flowlines, umbilicals, subsea control system, subsea equipment and risers.
Spares and tools include all capital movable assets (special tools, shipping containers, rotable spares and insurance spares), inventory (maintenance, repair and operating inventory) and consumables.
Sparing will ensure that lifecycle cost, schedule and integrity impacts arising from component failure and/or lack of consumables are managed to acceptable levels during manufacturing, testing, installation, pre-commissioning, commissioning and operation.
Sparing should be defined, delivered and maintained throughout the lifecycle of the field to satisfy:
- Subsea production system availability requirements during operation
- Repair scenario requirements identified through the application of Subsea Inspection, Monitoring, Maintenance and Repair Philosophy
- Guideline for selection, acquisition of production equipment operating inventory and commissioning spare parts
The subsea facilities should be designed to minimize planned maintenance and repair. However, in case subsea and pipeline maintenance is deemed required, it should be designed to be performed without diver assistance.
Sparing and tooling levels should be determined on the basis of a risk-based process which should evaluate the following issues:
- Credible demand scenarios throughout the life cycle:
- Manufacturing and testing spares and tooling: in the event of damage to, or failure of, equipment during manufacturing/testing processes
- Construction, installation and pre-commission spares and tooling: in the event of damage to, or failure of, special tools being used or equipment being installed. In the event of revealed damage or failure during pre-commissioning activities
- Operational spares and tooling: in the event of failure of installed equipment during operation, or equipment required for planned maintenance activities
- Lead time for sourcing spares
- Criticality to maintaining project execution schedule and production levels
- System redundancy
- Obsolescence, particularly with respect to electronic components such as those in the subsea control system (refer to Engineering Standard for Subsea Production Control System - API 17F)
- Time to mobilize vessels needed to effect repairs to the system
- Safety and environmental criticality associated with the item
Guidance for a risk-based spares selection process should be defined in project guideline for selection, acquisition of production equipment operating inventory and commissioning spare parts. Alternative processes may be used, subject to agreement between all parties.
Sparing requirements should be minimized through design standardization where practical.
Manufacturing and Testing Spares
Manufacturing and testing spares should be provided when required to maintain and avoid issues with delivery schedules.
Installation and Commissioning Spares
Installation and commissioning spares, including capital spares, should be provided to maintain and avoid issues with installation/commissioning schedules.
Installation tooling suites (including but not limited to wellhead tooling, tree system tooling, completion and workover system and connection tooling) should provide for one primary and one back-up operational tools for offshore installation purposes. This principle applies to all tools required by the planned installation operations but excludes contingency tools. In the case where a back-up offshore tool is not included in the rental suites, it should be justified by risk-based assessments subject to agreement with all parties.
Critical spares must be identified and provided to maintain the appropriate availability and maintainability of the tooling systems.
Initial operational sparing should be justified in conjunction with the installation and commissioning sparing and optimized to support post commissioning operations.
Operational spares should be justified on the following basis:
- Align with the operating requirements for the system as defined in Offshore Facility Operations Philosophy
- Be consistent with assumptions of the subsea system reliability analysis to deliver the target system availability performance
- Assessment of logistics support, storage facilities and the expected shelf life of stored spares
- Include assessment of risk-based maintenance requirements and cost of major capital spares
- Only support assumptions for credible intervention scenarios to achieve Production availability targets