Specifying a produced water monitoring system for an EPCI or EPCI contract is a significantly more demanding exercise than selecting a standard marine monitoring instrument. The EPCI environment introduces contractual, procurement, documentation and commissioning requirements that go well beyond the technical specification of the analyser itself — and errors made at the specification stage can create problems that are expensive and disruptive to correct during construction or commissioning.
This article covers the full specification process for produced water monitoring systems in the EPCI context — from regulatory mapping at concept stage through to the documentation package required for vendor qualification, procurement and handover to operations. For the technical specification process covering product selection, measurement technology and sample conditioning, see How to Specify an Oil-in-Water Monitor for FPSO Produced Water Discharge.
| Key thing to remember In an EPCI contract, the produced water monitoring system specification is not just a technical document — it is a contractual deliverable. The specification defines what the vendor must supply, what the FAT must demonstrate, what documents must be included in the documentation package and what the SAT must prove before handover. A specification that is incomplete or technically incorrect at FEED stage creates downstream contractual disputes, schedule risk and commissioning delays. |
What Is the Difference Between EPCI and EPC for Produced Water Monitoring?
Engineering, Procurement, Construction and Installation (EPCI) contracts — sometimes also referred to as EPIC contracts — assign responsibility for the complete project lifecycle to a single main contractor, including offshore installation of the FPSO topsides equipment. This is distinct from EPC contracts where installation is typically a separate scope.
For produced water monitoring systems, the EPCI scope typically includes:
- Engineering — produced water monitoring system specification, instrument data sheets, hook-up drawings, cause and effect diagrams, loop diagrams, control system narrative
- Procurement — vendor qualification, technical bid evaluation, purchase order, vendor document review and approval
- Construction — fabrication of the sample conditioning skid, panel building and factory testing
- Installation — offshore installation of the analyser, sample conditioning system, interconnecting pipework and electrical connections
- Commissioning — pre-commissioning loop checks, SAT execution, calibration verification and handover documentation
The EPCI contractor carries contractual responsibility for the monitoring system from specification through to demonstrated performance at SAT. This means the EPCI instrumentation team must specify the system correctly from the outset — because any specification error that reaches SAT becomes the EPCI contractor’s problem to resolve, often under time and cost pressure.
What Are the Key Stages of Produced Water Monitoring Specification in an EPCI Project?
The produced water monitoring specification develops progressively from concept through to commissioning. Each stage builds on the previous one and introduces additional detail. The table below summarises the key monitoring system activities at each project stage.
| Project stage | Key monitoring system activity | Why it matters |
| Concept and pre-FEED | Regulatory mapping — confirm which standard governs each discharge stream; define monitoring approach in principle; identify vendor qualification requirements | Early regulatory clarity prevents specification errors at FEED; confirms whether MEPC.107(49), permit or operator standard applies |
| FEED | Full monitoring system specification — discharge limit, measurement technology, sample conditioning, hazardous area classification, control system interfaces, documentation requirements | The FEED specification is the basis for procurement; errors at this stage flow through to detailed engineering, procurement and commissioning |
| Detailed engineering | Instrument data sheets, hook-up drawings, cause and effect diagrams, control system narratives, loop diagrams for the monitoring system | Translates the FEED specification into construction-ready documents; establishes the basis for FAT and SAT |
| Procurement and vendor qualification | Approved vendor list development, technical bid evaluation, vendor document review, purchase order technical schedule | Confirms the selected product meets the specification and that the documentation package satisfies the contract requirements |
| Fabrication and FAT | Factory Acceptance Test — performance verification at the manufacturer facility before shipment | Confirms the analyser meets specification before installation; any deficiencies resolved before the equipment leaves the factory |
| Installation and commissioning | SAT — full system test in the installed configuration including sample conditioning verification, alarm and shut-off functional test, data logging verification | Confirms the complete monitoring loop functions correctly; produces the SAT report required for handover to operations |
| Handover and first oil | Documentation handover — all certificates, calibration records, training records and as-built documents transferred to the operator | Provides the operator with the complete compliance record required for regulatory inspection from first discharge |
The most important stage is concept and pre-FEED — because this is where the fundamental specification decisions are made. The regulatory basis, the monitoring approach and the vendor qualification requirements must all be confirmed before detailed engineering begins. Decisions made at this stage are difficult and costly to reverse later.
How Do You Establish the Regulatory Basis Before Writing the Specification?
The starting point for any produced water monitoring specification is confirming which regulatory standard governs the discharge from each discharge point on the FPSO. This is a stream-by-stream exercise — different discharge points on the same FPSO may be governed by different standards.
The regulatory mapping exercise must confirm:
- Which discharge streams require monitoring — produced water from topsides processing, bilge water from the machinery space, tanker-derived slop or ballast discharge if the FPSO is a converted tanker
- Which regulatory standard governs each stream — field permit and national environmental law for topsides produced water; MARPOL Annex I and MEPC.107(49) for machinery space bilge water; MEPC.108(49) for tanker slop discharge
- What the applicable discharge limit is for each stream — expressed as ppm, monthly average, rate in litres per nautical mile or cargo fraction depending on the applicable standard
- What the monitoring method requirement is — continuous online monitoring, periodic grab sampling or a combination
- What type approval or certification is required for the monitoring equipment — MEPC.107(49) for OWS discharge monitors; ATEX or IECEx for hazardous area locations
This regulatory mapping exercise is the single most important input to the monitoring system specification. A specification written without confirmed regulatory basis cannot be verified against the applicable standard — and a monitoring system specified to the wrong standard cannot be commissioned.
What Must the FEED Specification Include for Produced Water Monitoring?
The FEED specification for a produced water monitoring system defines the technical requirements that the selected equipment must meet and establishes the basis for all subsequent engineering, procurement and commissioning activities. For the full technical content of a produced water monitoring specification, see the Produced Water Discharge Monitoring for FPSOs explainer page.
In the EPCI context, the FEED specification must cover:
Functional requirements
What the monitoring system must do — measure oil concentration continuously, activate an alarm if oil exceeds the set point, stop discharge automatically via the discharge shut-off valve, record all readings and alarm events with timestamps, and transmit the oil concentration reading to the DCS or ICSS.
Performance requirements
What measurement accuracy, response time and alarm set point the system must achieve — referenced to the applicable regulatory standard or permit discharge limit. The performance requirements must be specific and verifiable — they are the basis for the FAT acceptance criteria.
Sample conditioning requirements
The pressure, temperature, flow rate and filtration requirements for the sample conditioning system — defining what the sample must look like before it reaches the measurement cell. These requirements must be derived from the process conditions at the monitoring point, not assumed from product standard data sheets.
Hazardous area classification
The ATEX or IECEx zone classification of the installation location, which determines the certified protection concept required for the analyser and all associated electrical equipment.
Control system interface requirements
The DCS or ICSS tag numbers, signal types, alarm priorities, cause and effect requirements and data logging format — which must be agreed with the control system discipline before the monitoring system specification is finalised.
Vendor qualification requirements
The approved vendor list criteria — including type approval certificate requirements, ATEX certification, quality management system accreditation and previous FPSO project references — that a supplier must meet to be included in the bid list.
What Does a Produced Water Monitoring Vendor Qualification Package Include?
In an EPCI contract, the produced water monitoring vendor must be qualified before a purchase order can be placed. Vendor qualification confirms that the supplier has the technical capability, quality management system and project experience to supply a monitoring system that meets the specification and the contract requirements.
A typical vendor qualification submission for a produced water monitoring system includes:
- Type approval certificate — confirming the analyser is approved to MEPC.107(49) or the applicable standard, issued by an accepted flag state administration or classification society
- ATEX or IECEx hazardous area certificate — confirming the analyser is certified for the zone classification specified in the FEED specification
- ISO 9001 quality management system certificate — confirming the supplier’s manufacturing and service processes are subject to a certified quality system
- Technical compliance matrix — confirming compliance or non-compliance with each requirement in the technical specification, with explanatory notes for any deviations
- FPSO project references — evidence of previous supply of produced water monitoring systems on comparable FPSO projects, typically requested as a minimum of two or three completed project references
- FAT procedure — the supplier’s proposed FAT procedure, confirming all performance requirements in the specification will be tested before shipment
- Proposed documentation package index — a list of all documents the supplier will provide with the equipment, confirming the contract documentation requirements can be met
| Technical compliance deviations must be evaluated carefully A vendor qualification submission that indicates non-compliance with a specification requirement must be evaluated carefully. A deviation that is accepted at vendor qualification stage becomes a permanent feature of the supplied equipment — it cannot be corrected at SAT. All deviations should be reviewed by the lead instrumentation engineer and the project regulatory compliance team before a purchase order is placed. |
What Technical Bid Evaluation Criteria Apply to Produced Water Monitoring Systems?
Technical bid evaluation for a produced water monitoring system in an EPCI contract typically covers several categories of criteria, each weighted according to the project’s priorities:
Regulatory compliance
Does the proposed product hold a valid type approval certificate from the applicable flag state or classification society? Is the ATEX or IECEx certificate current and appropriate for the specified zone classification? These are pass or fail criteria — a non-compliant product cannot be accepted regardless of its technical performance.
Technical performance
Does the proposed product meet the measurement accuracy, response time and alarm set point requirements in the specification? The SMART PFM 107 uses optical microscopy to differentiate oil, gas bubbles and solids — a relevant technical differentiator for FPSO produced water streams where gas and solids interference are a known measurement risk.
Sample conditioning suitability
Is the proposed sample conditioning system correctly specified for the process conditions at the monitoring point — including pressure, temperature, flow rate and filtration? A technically capable analyser supplied with an inadequate sample conditioning system will not perform correctly in service.
Documentation package completeness
Does the vendor’s proposed documentation index cover all contract documentation requirements? Missing documentation is a frequent cause of EPCI contract disputes and handover delays. All required documents should be identified at bid stage, not discovered as missing at handover.
Calibration capability
Can the vendor calibrate the analyser against the FPSO crude oil type at FAT? The OCD Xtra can be factory calibrated on up to six crude oil types and adjusted onsite against laboratory analysis — a relevant capability where crude composition changes over the field life or where the FPSO produces from multiple reservoir zones.
Offshore service and support
Does the vendor have a global service engineer network capable of supporting the instrument offshore for calibration, maintenance and cell replacement across the operating life of the FPSO? Offshore service access should be confirmed at bid evaluation, not at the point when service is needed.
What Documentation Package Is Required at Handover?
The documentation package for a produced water monitoring system must be complete before handover to operations can take place. The table below sets out the standard documents required.
| Document | What it confirms |
| Type approval certificate | Confirms the analyser is approved to the applicable MEPC resolution — MEPC.107(49) for produced water and OWS discharge |
| ATEX or IECEx certificate | Confirms the analyser is certified for the hazardous area zone classification at the installation location |
| Manufacturer quality plan | Confirms the quality management system under which the equipment is manufactured — typically ISO 9001 |
| Instrument data sheet | Technical specification document confirming all performance parameters, operating conditions and electrical data |
| FAT procedure and report | Pre-agreed test procedure and completed test report demonstrating performance against specification |
| Calibration certificate | Issued at FAT confirming accuracy against the specified crude oil reference; must be available at SAT and at handover |
| Hook-up drawing | Piping and instrument diagram for the sample conditioning system and analyser installation |
| Loop diagram | Wiring diagram for the analyser to DCS or ICSS interface and discharge shut-off valve connection |
| Cause and effect diagram | Documents the alarm logic and automatic discharge shut-off response |
| SAT procedure and report | Pre-agreed site test procedure and completed SAT report covering all commissioning checks |
| O&M manual | Operations and maintenance manual covering installation, commissioning, routine maintenance, calibration and troubleshooting |
| Spare parts list | Recommended spare parts for the commissioning period and first year of operation |
For a detailed breakdown of what commissioning inspectors check against this documentation at first oil, see What Happens During an FPSO Commissioning Inspection for Produced Water Systems?.
What Are the Most Common EPCI Specification Mistakes for Produced Water Monitoring?
Experience across FPSO EPCI projects has identified several recurring specification mistakes that create problems at bid evaluation, procurement, FAT or commissioning:
- Regulatory basis not confirmed before writing the specification — the specification references the wrong standard or applies a generic 15ppm limit to a permit-governed produced water discharge stream
- Sample conditioning requirements not derived from the process conditions — the specification states the analyser operating range without confirming that the process conditions at the monitoring point are within that range
- ATEX zone classification not confirmed before bid — the specification requires ATEX certification without specifying the zone, making it impossible for vendors to confirm compliance
- FAT crude oil reference not specified — the specification does not state which crude oil the FAT accuracy test must be conducted against, allowing vendors to use a generic reference that may not be representative of the FPSO crude
- Documentation requirements not specified at bid stage — the purchase order does not list all required documents, leading to disputes at handover when the operator requests documents the vendor was not contracted to supply
- Control system interface requirements not finalised before bid — the specification references DCS tags and signal types that have not yet been agreed with the control system discipline, preventing vendors from confirming compliance
Frequently Asked Questions
What is the difference between an EPCI and EPC contract for FPSO produced water monitoring?
An EPCI contract assigns responsibility for Engineering, Procurement, Construction and Installation to a single main contractor — including offshore installation of the FPSO topsides equipment. An EPC contract typically stops at construction and fabrication, with installation as a separate scope. For produced water monitoring, the EPCI scope includes specification, procurement, fabrication, offshore installation, commissioning and handover documentation — all under one contractor’s responsibility.
When should the regulatory basis for produced water monitoring be confirmed in an EPCI project?
The regulatory basis should be confirmed at concept or pre-FEED stage — before the FEED specification is written. Confirming the regulatory basis at this stage ensures the specification is written to the correct standard, the vendor qualification requirements are defined correctly, and the FAT and SAT acceptance criteria are aligned with the applicable regulatory requirement.
What type approval certificate is required for a produced water monitoring system on an FPSO?
For produced water discharge from FPSO topsides processing governed by a field permit, the type approval requirement is defined by the permit conditions and the applicable national regulatory standard rather than a single IMO MEPC resolution. For produced water discharge from oily water separator systems on the FPSO, MEPC.107(49) type approval is required. The applicable certificate must be confirmed from the regulatory mapping exercise before the specification is written.
What should be included in the FAT for a produced water monitoring system?
The FAT should verify measurement accuracy against a reference sample of the specified FPSO crude oil type, response time to a step change in oil concentration, alarm activation at the correct set point, analogue output signal accuracy across the full measurement range, discrete alarm and shut-off outputs, and data logging function. The FAT procedure should be agreed with the vendor before the purchase order is placed and the completed FAT report should be reviewed and signed off before the equipment is released for shipment.
How does Rivertrace support EPCI teams at the specification stage?
Rivertrace provides application engineering support to EPCI instrumentation teams from concept stage through to commissioning. This includes regulatory mapping to confirm the applicable standard for each discharge stream, technology selection advice, sample conditioning system guidance, hazardous area certification confirmation, preparation of the technical compliance matrix and documentation package index, FAT procedure review, and SAT support. The earlier Rivertrace is involved, the greater the opportunity to prevent specification errors before they become procurement or commissioning problems.