Subsea Control Systems

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Shawn Mathews
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1 Subsea Control Systems

Simplifying Subsea Production INGENIOUS SIMPLICITY Proserv s direct hydraulic and multiplexed production subsea control systems provide control and shutdown of subsea wells together with robust

2 Simplifying Subsea Production INGENIOUS SIMPLICITY Proserv s direct hydraulic and multiplexed production subsea control systems provide control and shutdown of subsea wells together with robust communications that enable the topside management and monitoring of subsea activities. We specialise in subsea control modules and communication distribution and surveillance equipment for offshore production optimisation, control and monitoring to customers around the globe. Our subsea control and monitoring solutions can be installed and interfaced to subsea trees from all major manufacturers with open architecture communications and modular designs for adaption to suit specific project requirements. Our innovative range of services are briefly outlined on the following pages, however if you require further information please us or check our website for regional contact details:

Introduction Proserv s integrated system provides the required monitoring, control and shutdown functions by means of multiplexed electro-hydraulic control.

3 Introduction Proserv s integrated system provides the required monitoring, control and shutdown functions by means of multiplexed electro-hydraulic control. Communications are provided using communications-on-power modems between a surface Master Control Station (MCS) and Subsea Control Module (SCM) via a composite services umbilical and appropriate subsea distribution unit(s). In addition to the control module, a data module may be used to bring open communications to a field to integrate Proserv and third party communication devices, for example flow metering or downhole sensing. The data or control module system is designed for deployment and intervention by means of a Remotely Operated Vehicle (ROV) or diver intervention using a similar module. Assisted guideline and non-guideline running tools or funnels are available with ROV assistance in very deep water. These feature a simple sliding plate design that locks down the mechanism. Electric and hydraulic connections to the ROV SCM are made using low force connectors, mounted on the base of the unit, which connect when the unit is locked into place and via a stab-plate arrangement for diver installed systems. The MCS provides the subsea power and communications interface between the installed subsea control module(s), the platform/vessel control system and any other third party systems, via serial or Ethernet based network connections. The modular MCS provides a compact and flexible solution for ease of integration into new or existing equipment rooms. Equipment can also be supplied for hazardous area installation. Mechanical The SCM housing is filled with dielectric fluid prior to installation and is pressure compensated to safeguard against over or under pressurisation. The SCM housing is fabricated from structural steel manufactured to BS EN Grade Fe430C or Fe510 D1/D2 and finish painted to our standard subsea paint specification. All hydraulic and electric couplings are manufactured from 316 stainless steel or better. The hydraulic system consists of self latching solenoid operated shear seal directional control valves mounted on a stainless steel block manifold, with single or dual hydraulic supplies dependent on client s specifications. Electrically held-open valves can also be mounted in this unit for Emergency Shutdown (ESD) system functionality if required. Individual High Pressure (HP) and Low Pressure (LP) hydraulic supply filters are mounted within the control module maintaining fluid cleanliness specifications. Both hydraulic supplies have pressure transducers to indicate system pressure within the control module. The tree valve hydraulic actuator inferred status is sensed by individual pressure transducers, integral to the directional control valves, which relay the function line pressures to topside where they may be displayed on the MCS screen and made available to the Distributed Control System (DCS)/platform control system. A modular design concept, electro-hydraulic multiplex subsea control system incorporating proven technology and qualified components to minimise both CAP EX and OPEX costs. An accumulator can be accommodated within the control module to help prevent pressure drop during valve operations on large step outs. Alternatively, separate subsea accumulator modules can be provided to maintain local pressure levels. Standard Functions/Features Four HP hydraulic outputs Twenty two LP hydraulic outputs Dual HP and LP hydraulic inputs via shuttle valve HP and LP ESD valve Directly mounted digital control valves to single manifold block HP and LP vents to sea or closed loop returns

Subsea Control Module Electronics External The Subsea Electronics Module (SEM) has been designed to be surface removable and replaceable without the need to disturb the module s hydraulics chamber.

4 Subsea Control Module Electronics External The Subsea Electronics Module (SEM) has been designed to be surface removable and replaceable without the need to disturb the module s hydraulics chamber. It houses power, communications, control and third party interface electronics. The housing provides a one-atmosphere dry nitrogen purged environment located within the main SCM housing. Proprietary penetrators provide connection to the SCM and external tree instrumentation. Communications between surface and subsea are by means of a redundant Intelligent Well Interface Standardisation (IWIS) Point-to-Point Protocol (PPP) compliant power line carrier modem providing Ethernet, RS232 and RS4XX with open protocol connectivity. Communications can be implemented to suit comms-on-power, separate comms-and-power or fiber optic that is dependent on client and application requirements. A configurable frequency band of operation (50 to 690 khz) enables integration and co-existence with other legacy powerline modems to develop existing system extensions of control and/or data devices. The available system bandwidth range is 1 to 390 kbps, dependant upon umbilical cable characteristics. The SEM provides control and data monitoring via a dedicated embedded processor with scalable and configurable input/output channel configurations to suit client and application requirements. Communications for data retrieval or control commands with the SEM processor is by Modbus RTU protocol. In addition, the SEM incorporates internal diagnostic monitoring for internal power supplies, environmental, processor status and communications. Extensive system configuration and diagnostic tools and displays are available to the users via the topside MCS workstation. Note: User levels of security access are applied to ensure the safety and ease of use for the system. SEM Standard Functions Standard Unit has single SEM (dual SEM optional) providing 4 to 20 ma (standard), discrete input/output instrumentation and controls interfaces Fully dual redundant power supplies and communication channels Housekeeping functions including internal voltage/current monitoring, internal pressure, temperature and humidity Mounting, power and communication interfaces for third party devices, IWIS compatible Fast scan analogue data capture with configurable sample rates Ethernet, RS232 and RS4XX (2 off) communication ports; fully IWIS PPP compatible for true open architecture Quad Access Control provides media synchronisation to enable two pairs of quad to be individually used, avoiding cross-talk issues Multi-drop architecture with individual remote device frequency and bit-rate configuration/selection to optimise system data and control performance Carbon steel fabricated housing, painted to standard subsea paint specification Installation and intervention by ROV assisted running tool, funnel or diver onto mounting base Dielectric fluid filled pressure compensated housing and atmospheric SEM housing Designed for use up to 3000 meters of water 1.5 atmosphere nitrogen filled electronics housing with pressure and temperature monitoring Dual HP and LP supplies, incorporating individual hydraulic supply line filters with B3 = 200 rated elements Control of hydraulic valve actuators by stainless steel body, sheer seal type solenoid valves Earth strap for bonding and low resistance connection to the module mounting base on the manifold cathodic protection system Connection points legibly identified by proprietary laminated nameplates Stand alone sacrificial anodes for cathodic protection will be provided based on isolation for six months on the seabed Two outgoing electro-hydraulic ROV/diver stabplates both mounted on SCM mounting base Communications Topside DCS and third party interfaces: Serial, Ethernet, fiber-optic solutions with a full range of standard industry protocols available Subsea interfaces: Transparent RS232, RS4XX and Ethernet connectivity Profibus, CANbus, Modbus RTU and TCP implemented Full IWIS PPP compliant interface Fiber optics

Design Criteria Test Equipment A range of test equipment is available for rent or to purchase: Environmental Data Cable simulators Test MCS Water Depth Operating temperature range ( F/ C) Shock

5 Design Criteria Test Equipment A range of test equipment is available for rent or to purchase: Environmental Data Cable simulators Test MCS Water Depth Operating temperature range ( F/ C) Shock Vibration 3,000 m LAT Surface unit = 23 to 104 (-5 to 40) Subsea unit = 23 to 104 (-5 to 40) iaw ISO iaw ISO EMC iaw ISO Subsea Equipment Design Design life Intervention SCM size (in/mm) (L x W x H) SCM weight SCM housing Mounting 25 y ROV or diver deployment and intervention 33.5 x 33.5 x 3 (850 x 850 x 75), excluding mounting base (lb/kg) In air, 1874 (850) In water, 1323 (600) approximately Pressure compensated, dielectric fluid filled Subsea tree or manifold structure (ROV to API 17 H or diver) System Pressures and Fluid High pressure Low pressure Control fluid Control fluid cleanliness Supply filtration Electrical Analog ue Discrete Power supply Communications (psig/barg) 15k (1034) MWP (psig/barg) 5k (345) MWP Water based biodegradable, open loop or petroleum based synthetic mineral oil (standard) NAS 1638 Class 6 Integral single B3 200 rating elements (3 micron) 4 to 20 ma (standard) 12-bit, other configurations available 24 VDC, 0.5 to 8 A (maximum) output configurable 24 VDC input configuration available 110, 230 or 480, 50/60 Hz single phase (nominal), 24 VDC (option) Comms-on-power, comms-and-power and/or fiber optic The test stand (shown above without enclosure panels) is designed for onshore/ offshore testing and commissioning, or for use on vessel prior to deployment of the SCM. The stand is a fully integrated unit consisting of hydraulic power unit, pumps, filters, tree valve actuator simulators and self contained controls computer panel.

16/09/2014. Introduction to Subsea Production Systems. Module structure. 08 Production Control Systems

16/09/2014. Introduction to Subsea Production Systems. Module structure. 08 Production Control Systems OIL & GAS Introduction to Subsea Production Systems 08 Production Control Systems September 2014 DNV GL 2013 September 2014 SAFER, SMARTER, GREENER Module structure Section 1 Introduction to control systems