Controls
Revision as of 05:40, 21 October 2016 by Cameronadams777 (talk | contribs)
Simplified Electrohydraulic Multiplex System Circuit Diagram
Uninterruptible Power Supply (UPS)
- Provides safe and reliable electrical power to the subsea production controls equipment.
- Able to maintain a steady supply, even when the main source fluctuates or fails.
- Provides power for the production control system during input power failure.
- Rating based on project requirements and capable of maintaining 100% load for a minimum of 1/2 hour (per API 17F)
Electrical Power Unit (EPU)
- Provides redundant, conditioned power to the topside and subsea production controls system equipment.
- It is a modular design based on standard 19 inch units.
- Local panel meters display the input/output power parameters for all connected subsea equipment.
- All operating parameters are sent to the MCS for display and alarming.
Master Control Station (MCS)
- Main operator interface
- Typically a PC or PLC based
- Modular design based on standard 19 inch units
- Displays information from the subsea equipment
- Implement interlocks to prevent inadvertent errors
- Executes shutdowns
- Monitors functions and alarms on specific conditions
- Record data and alarms
- Event Logging
Human Machine Interface (HMI)
- Main operator interface
- Mimics the actual system control circuits and equipment interconnections
- Displays information from the subsea equipment
- Allows the operator to change set points, view and setup trends, generate reports, and execute commands
Remote Operator Station (ROS)
- Provides an operator interface with full monitoring and control of the Production Control System.
- Typically located in the main operator room.
- Usually consist of a desktop PC with flat screen monitor and printer.
- Connects to the MCS via a redundant Ethernet link.
- Offers the same HMI functionality provided at the MCS.
- Powered by a UPS for continued operation during power failures.
Hydraulic Power Unit (HPU)
- Provides clean, regulated pressurized hydraulic fluid to operate actuated functions subsea.
- Redundant High Pressure (HP) and Low Pressure (LP) circuits are typically provided.
- Contains Electrical or Pneumatic pumps.
- Accumulators for stored hydraulic supply and continued operation with power or pump failures.
- Local control panel for manual operation of pumps, service and maintenance activities.
- Supply and Return hydraulic reservoir for stored fluid.
Topside Umbilical Distribution Unit (TUDU)
- Located close to the umbilical I-tube or J-tube
- Electrical junction box rated for the environment
- Fiber Optic junction box rated for the environment
- Hydraulic/chemical enclosure
- Hydraulic/chemical supplies w/ block, bleed valves & gauges
- Return lines to platform
- Annulus monitor line
Subsea Equipment
- Umbilical Termination Assembly (UTA)
- Subsea Distribution Unit (SDU)
- Subsea Controls Module (SCM)
- Subsea Electronics Module (SEM)
- Subsea Controls Module Mounting Base (SCMMB)
- Subsea Accumulator Module (SAM)
- Subsea Accumulator Module Mounting Base (SAMMB)
Umbilical Termination Assembly (UTA)
- Terminates the umbilical services subsea
- Distributes hydraulics, chemicals, power and communication services to each tree/control module
- Includes bend limiters for subsea end of umbilical
- Bolted flange used to secure the umbilical
- Designed to provide an efficient offshore handling, installation, and retrieval method
- Detachable subsea support structure secured to the seabed (stab & hinge, mud mats, piles, etc.)
- Electric/Optical/ Hydraulic jumpers connected by ROV friendly stab plates
Subsea Distribution Unit (SDU)
- Distributes hydraulics, chemicals, power and communication service to each tree/manifold control modules
- Designed to provide an efficient offshore handling, installation, and retrieval method
- Detachable subsea support structure secured to the seabed (mud mats, piles, etc.)
- Flying Leads connected by ROV friendly stab plates and connectors
- Isolation valves for chemicals and hydraulic supplies
- Locally mounted control and/or accumulator modules
Subsea Control Module (SCM)
- Controls Tree and Manifold valves
- Monitors the DHPT, Tree/Manifold pressure, temperature, flow, sand and pig detectors
- Monitors the choke position and upstream/downstream pressures
- Dual redundant hydraulic/electric supplies and Dual SEM's
- ROV retrievable
- Accumulation integrated into the SCM or separated modules
- Mounted directly to production/injection trees, and manifolds
Control System Drivers
- Host Facility
- Water Depth
- Field Layout
- Offset(s)
- Well Location (cluseter/spread), offset distance, no of wells
- Wells
- Shut-in Pressure
- Shut-in Temperature
- Tree Valve Characteristics - Tree Manufacturer (water depth & shut-in pressure)
- SCSSV (tubing pressure profile), set depth - supplier (operational characteristics)
- Mitigation Requirements
- Hydrate
- MEOH/LDHI strategy & flow rate
- Chemical
- Different types, flow rates
- Erosion/Sand
- Erosion Detector
- Sand Detector
- Hydrate
- Manifolds
- Functional Requirements - Production Strategy/Operational Requirements
- Pig Detector
- MPFM
- PTT