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Subsea Umbilical, Controls Testing and Pre-Commissioning Requirements

 

1. INTRODUCTION

1.1 Project Overview

This document provides the requirements for testing and commissioning of the umbilicals and subsea production controls system.

1.2 Documentation

The following documentation should be delivered to the Owner project team on the following schedule.

DocumentSchedule
Installation Procedures One month prior to installation
Installation Checking Procedures One month prior to installation
Pre-Commissioning Procedures One month prior to commissioning
As Built Drawings One month prior to installation
Installation Check Report Prior to final payment
Pre-Commissioning Report Prior to final payment


Contractor should provide a complete list of equipment required supporting the installation checking and pre-commissioning work. This list should include part numbers & quantity supplied by Contractor.

The procedures for all activities must include sign-off (initial) blanks for each step and an area for data to be recorded where applicable for each step. Witness and hold points will also be included in each procedure.

2. REFERENCES

2.1 Codes and Standards

API RP 2A Recommended Practice for Planning, Designing, and Constructing Fixed Offshore Platforms
API 6A Specification for Wellhead and Christmas Tree Equipment
API 14D Specification for Wellhead and Surface Safety Valves and Underwater Safety Valves for Offshore Service
API 17D Specification for Subsea Wellhead an Christmas Tree Equipment
API 17F Specification for Subsea Production Control Systems
API 505 Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Zone 0, Zone 1 and Zone 2
NAS 1638 Hydraulic Control Fluid Cleanliness Requirement
ANSI/AWS D1.1 Structural Welding Code, Steel.
ISO/CD 13628-8 Design and Operation of ROV Interfaces on Subsea Production Systems
ISO/CD 13628-9 Design and Operation of Subsea Production Systems Intervention Systems

2.2 Terms and Abbreviations

The following abbreviations and definitions are used in this document:

DCS Distributed Control System
DHPT Downhole Pressure and Temperature
EFL Electrical Flying Lead 
EJB Electrical Junction Box
ESD Emergency Shutdown
ESS Emergency Shutdown System
ETU Electronic Test Unit
FAT Factory Acceptance Test
FSC Fail Safe Closed
FSO Fail Safe Open
HFL Hydraulic Flying Lead
HMI Human Machine Interface
HPU Hydraulic Power Unit
HP High Pressure
LP Low Pressure
MCS Master Control Station
MODU Mobile Offshore Drilling Unit
PLC Programmable Logic Controller
PSD Process Shutdown
PTT Pressure/Temperature Transducer
ROV Remote Operated Vehicle
SCM Subsea Control Module
SCSSV Surface Controlled Subsea Safety Valve
SDU Subsea Distribution Unit
SEV Subsea Equipment Vendor
SIC Subsea Installation Contractor
SPCU Subsea Power and Communications Unit
TUTU Topside Umbilical Termination Unit 
UPS Uninterruptible Power Supply

3. TECHNICAL REQUIREMENTS

3.1 Description

Following the complete installation of the umbilicals and production controls equipment, a series of testing and pre-commissioning work should be preformed. Once completed, the production controls system and umbilicals will be ready for operations to commission each subsea center.

The first round of testing will be installation checks and operations which prepare each set of equipment for the pre-commissioning phase. The installation procedures will most likely include testing to be conducted just after installation by the installation Contractor. However, these tests along with other more detailed test should be conducted to ensure the system is ready for operation. Interconnection between groups of equipment should also be completed during this installation checking process. The installation checks for each group of equipment can be preformed in any order.

Pre-commissioning activities will commence when all installation checks are complete and the pre-requisites have been met and will be conducted in the order shown in this document. The purpose of pre-commissioning make the entire production controls system ready for transfer of ownership to the Owner.

3.2 HSE

Considerations for health, safety, and environment should be maintained throughout all testing and pre-commissioning activities. Procedures should include Job Safety Analysis at the beginning of each activity or shift change. Personal protection equipment requirements should be defined in all procedures as well. At no time during any of the operations below should the SCSSV be opened. In addition to the closed SCSSV, one other barrier should be maintained between hydrocarbons and the production stream at all times.

Pressure test should include a method to prevent over pressurization of the system. These operations should not exceed 1.1 times the working pressure at any time. 

3.3 Responsibility

All activities defined within this document should be conducted by the SEV or their sub-Contractor, with assistance from platform personnel when required. All equipment should be supplied by the SEV or their sub-Contractor. Any fluid disposal requirements from flushing operations are the responsibility of the SEV.

3.4 Acceptance Criteria

Procedure steps that require a test or measurement should define acceptance criteria for that step. The acceptance criteria will be agreed to by the Owner (or modified) during the review and approval process for each procedure.

4. INSTALLATION CHECKS

Installation checks should be performed on each set of equipment as defined below by following detailed procedures generated by the SEV.

4.1 Hydraulic Power Unit

The HPU should be installed and connected to external interfaces possibly months before commissioning activities on the platform. The following checks will verify all connections and prepare the HPU to supply hydraulic fluid to the subsea centers.

4.1.1 Pre-requisite Conditions

The following minimum conditions must be defined and met prior to beginning the procedure:

  • Tubing connected between HPU and TUTU
  • TUTU downstream (umbilical side) isolation valves are closed
  • Electric Motors connected to motor control station
  • 120 VAC supply from UPS connected
  • Utility Air supply connected
  • Instrument Air supply connected
  • Control serial line connected to MCS
  • Shutdown signal wires connected to ESS

4.1.2 Required Equipment

Below is a minimal list of equipment required for the installation check:

  • Sufficient quantity of control fluid to charge each subsea center
  • Control fluid fill pump with filter unit and connection hoses to tote tanks and HPU
  • Digital multi-meter

4.1.3 Objectives

The installation checking procedure will contain the details associated with the objectives listed below. These objectives comprise an initial list of check points and activities which should be included in the procedures.

  • Confirm all external connections
  • Fill Reservoir
  • Check accumulator nitrogen pre-charge pressure
  • Confirm proper valve positions for operation
  • Verify operation of PLC
  • Measure shutdown signal voltage from DCS
  • Confirm all pumps operate correctly
  • Flush each HP and LP umbilical line by circulating through the TUTU by setting up loops (e.g. Down LP circuits and back HP)
  • Charge HPU accumulators and set regulators to operating pressure

4.2 Umbilicals

The umbilicals should have been installed to the platform and tested by the Subsea Installation Contractor (SIC). The following checks will verify whether all umbilical tubes will hold pressure and prepare the umbilicals to supply electrical power and signals, hydraulic pressure, and chemicals to the subsea centers.

4.2.1 Prerequisite Conditions

The following minimum conditions must be defined and met prior to beginning the procedure:

  • Umbilicals installed and secured to I-tube
  • Hydraulic and Chemical tubes pressure tested by installation Contractor
  • Electrical quad continuity and resistance measurement verified by installation Contractor
  • TUTU installed
  • Chemical bulkhead installed
  • Umbilical Termination Assembly includes stab plates
  • Umbilical Termination Assembly includes looped electrical protection caps

4.2.2 Required Equipment

Below is a minimal list of equipment required for the installation check:

  • Test HPU
  • Flushing unit
  • Tote tank(s)
  • Digital multi-meter
  • Electrical test connectors to mate with umbilical quad connectors
  • Chart recorder with appropriate scale charts
  • Fluid cleanliness analysis equipment

4.2.3 Objectives

The installation checking procedure should contain the details associated with the objectives listed below. These objectives comprise an initial list of check points and activities which should be included in the procedures.

  • Measure conductor resistance
  • Measure insulation resistance
  • Connect electrical quad to EJB
  • Flush LP/HP tubes to required cleanliness level
  • Connect chemical tubes to bulkhead
  • Connect HP and LP tubes to TUTU
  • Pressure Test LP tubes to design pressure (1.1 times working pressure) through TUTU vent connection with HPU side isolation valves closed
  • Pressure Test HP tubes to design pressure (1.1 times working pressure) through TUTU vent connection with HPU side isolation valves closed
  • Pressure chemical tubes through bulkhead vent connection with injection skid side isolation valves closed

4.3 MCS, SPCU, UPS, and DCS

The subsea controls system consists of several interconnecting cables between the MCS, SPCU, UPS, and DCS which should be installed per a procedure by the SEV. The following installation checks will ensure all connections are in place and the equipment is operating properly.

4.3.1 Prerequisite Conditions

The following minimum conditions must be defined and met prior to beginning the procedure:

  • MCS, UPS, SPCU, and DCS all interconnected as required for operation
  • System software has been installed
  • Cables have been installed from SPCU to EJB
  • Control serial line connected to HPU
  • Shutdown signal wires connected to ESS

4.3.2 Required Equipment

Below is a minimal list of equipment required for the installation check:

  • Digital multi-meter
  • Electrical Test Unit (ETU)
  • Electrical test connectors to mate with EJB connections

4.3.3 Objectives

The installation checking procedure should contain the details associated with the objectives listed below. These objectives comprise an initial list of check points and activities which should be included in the procedures.

  • Equipment Inspection
  • Verify correct system software version
  • Continuity Testing between SPCU and EJB
  • Measure shutdown signal voltage from DCS
  • Confirm proper ground where applicable
  • UPS Operation Check
  • SPCU Operation Check
  • MCS Operation Check
  • MCS Communications verification w/ Test SCM (ETU in subsea mode)
  • DCS Communications verification w/ Test SCM (ETU in subsea mode)
  • Remote Terminal DCS Communications verification w/ Test SCM (ETU in subsea mode)
  • ESD Verification through ESS signal wires

5. PRE-COMMISSIONING

5.1 HPU

Prior to start-up of any subsea center, the HPU must be set in operation mode for control of the pumps and monitoring instrumentation. Pre-commissioning of the production HPU will consist of, as a minimum, the following activities.

5.1.1 Prerequisite Conditions

The following minimum conditions must be defined and met prior to beginning the procedure:

  • HPU Installation checks are complete
  • All HP and LP umbilical tubes are connected to TUTU
  • TUTU isolation valves are open and vent valves are closed

5.1.2 Assumptions

  • MCS is ready for operation
  • ESS is supplying 24VDC for all shutdown signals

5.1.3 Objectives

The installation checking procedure should contain the details associated with the objectives listed below. These objectives comprise an initial list of check points and activities which should be included in the procedures.

  • Confirm utility and instrument air supply pressure
  • Turn on PLC and verify proper operation
  • Place HP and LP pumps into Auto position
  • Confirm control fluid volume availability to charge all subsea centers

5.2 Umbilicals

Pre-commissioning of the control umbilicals will consist of a final pressure check with the flying leads installed to each tree or manifold. The storage fluid, control fluid, and water in the chemical lines in umbilicals and flying leads should be displaced with the proper chemical by operations during the commissioning phase.

5.2.1 Prerequisite Conditions

The following minimum conditions must be defined and met prior to beginning the procedure:

  • Umbilical installation checks completed
  • HPU installation checks completed
  • SDU is installed with flying leads to UTA
  • Initial (all startup) HFLs and EFLs are installed to trees and manifolds
  • MCS and SPCU installation checks are completed and it is operational
  • For subsea trees ready for pre-commissioning their respective chemical bulkhead isolation valves are open and vent valves are closed, all other isolation valves are closed
  • Flowlines are pre-commissioned and ready to take displaced fluids from chemical tubes

5.2.2 Assumptions

  • HPU is ready for pre-commissioning
  • All Tree and Manifold chemical injection valves are closed (no overrides) and ready for pressure test through HFL
  • Chemical injection skids are operational and filled with appropriate fluid
  • Flow assurance has reviewed chemical compatibility and recommended buffer fluids if necessary
  • HP and LP pressure test will be performed at separate times to ensure Tree valves and SCSSV are never opened at the same time
  • Displacement of fluids portion of umbilicals pre-commissioning will be performed during MCS pre-commissioning operations

5.2.3 Required Equipment

Below is a minimal list of equipment required for the installation check:

  • Test HPU
  • Tote tank
  • Chart recorder with appropriate scale charts

5.2.4 Objectives

The installation checking procedure should contain the details associated with the objectives listed below. These objectives comprise an initial list of check points and activities which should be included in the procedures.

  • Pressure Test LP tubes through HFL to Tree/Manifold with production HPU to working pressure
  • Pressure Test HP tubes through HFL to Tree/Manifold with production HPU to working pressure
  • Pressure test chemical lines through HFL to Tree/Manifold with Test HPU connected at chemical bulkhead to working pressure

5.3 MCS

The final phase of pre-commissioning before the production control system is available for operations is the pre-commissioning of the MCS. Following is a list of minimal requirements for the pre-commissioning of the MCS.

5.3.1 Prerequisite Conditions

The following minimum conditions must be defined and met prior to beginning the procedure:

  • MCS, UPS, SPCU, and DCS installation checks are completed
  • Tree installed
  • Manifold installed
  • HFLs connected to stab plate
  • EFLs connected to SCMs

5.3.2 Assumptions

  • Displacement of fluids portion of umbilicals pre-commissioning will be performed during these operations
  • ROV will monitor all valve operations to confirm valve position

5.3.3 Required Equipment

Below is a minimal list of equipment required for the installation check:

  • ROV

5.3.4 Objectives

The installation checking procedure should contain the details associated with the objectives listed below. These objectives comprise an initial list of check points and activities which should be included in the procedures.

  • MCS Communications verification with each Production Tree SCM
  • MCS Communications verification with each Water Injection Tree SCM
  • MCS Communications verification with each Manifold SCM
  • PTT signal confirmation on each tree
  • DHPT signal confirmation on each production tree
  • Choke Position Indicator signal confirmation (without moving choke)
  • Manifold sensor signal confirmations
  • SCM channel switching verification
  • Tree and Manifold Valve operations
  • Hold chemical injection valves opened while pumping chemicals into the umbilicals and methanol flowline from topsides
  • Valve Signature Recording
  • ESD Checks
  • Interlocks Check

 

 

Tags: Subsea Control Umbilical