Long Distance Challenges -Control Systems

Transcription

1 Long Distance Challenges -Control Systems Vidar Sten-Halvorsen, FMC Holmenkollen Park Hotel Oslo February 2008

2 Challenges for ultra long step out distances Challenges and solutions for traditional systems Hydraulic distribution Hydraulic fluids Electric power distribution Communication Alternative solution All electric controls Telecom solution for umbilical, power and communications demonstrated with all electric system

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5 Hydraulic distribution: Umbilical: Long Step out case Shtokman 19 mm lines necessary (LP, HP, return) i.e litre of fluid resident in umbilical Approx 25 years transit time for fluid in umbilical under normal operation Hydraulic system Closed hydraulic system with return lines in umbilical Hydraulic operation with supply from topside is possible. Quick dump valves and active receivers for ESD and small bore return lines. Time-consuming pressurising. Accumulators on manifold and/or XT Umbilical reduction possibilities: Pressure intensifiers in SCM field proven, HP lines no longer necessary Subsea HPU, umbilical not necessary. Extra power consumption and control. Cleanliness of recycled fluid an issue.

6 Electric Power distribution and communication Typical power load: AC Ormen Lange system: 160 W per SEM (peak) Approx 50 wells with redundant SEM s: 16 kw total Traditional 50 Hz not feasible due to losses 3 phase 5kV, 16 2/3 Hz; 3x50 mm 2 just possible with very low efficiency DC Better efficiency over long distances Electric communication Limited to 200km distance with modems without repeaters

7 Power transmission:- AC vs DC % DC current efficiency (%) AC current efficiency (%) length 400(km) AC (50Hz) systems limited to km Source: Alcatel DC systems transfer useful power over 1000+km

8 Communication Systems Existing Modems: 2.4 kbps FSK Modem, half duplex 33.6 kbps LongSpeed, full duplex 8 Mbps Fibremodem, single fiber, full duplex Adaptations of available technology (Ethernet based): 10/100 Mbps typically up to 150 km high speed fibre modem Telecom Industry Standard Equipment, gbps 1 Mbit shorter distance, 1-20 km typically, marinized electric point to point modems based on DSL technology Ongoing Development: Long distance max 56.6 kbps multidrop modem for primary and back-up communication where feasible

9 New 200e System Ethernet Backbone, from office to subsea High speed communication, up to 1 Gbps typically Use of Managed Switches to Control Traffic Utilizes industry standard interfaces Facilitates transparent links 10 times more Powerful than previous systems Backwards compatible Compatible with fibreoptics

10 Electric Control System Components escm Electric Actuator EA 25 Electric Actuator EA 50 FS Electric Actuator EA 50

11 Applications Electric Technology so far seen as supplement to E-H systems Standardized products, only valve interface is project specific Typical applications: Tie-back manifolds Water injection satellite trees Electric chokes Process systems Subsea Production Systems Ultra long step out projects are attractive applications for this technology limited electric power avoiding hydraulic lines

12 Electric Subsea Systems FMC s Approach to Electric Systems Low voltage approach: Utilizes existing low-power umbilicals and connectors Provides a safer operating environment Reduces topside power equipment Requires power only as needed for valve operation All system components are separately retrievable allows retrieval of electric equipment while producing low risk implementation of new technology Redundant Control modules Plug and Play connectivity

13 Pilot Electric System Statoil Statfjord Need Remote Operation of subsea chokes to enhance oil recovery Sand Monitoring Solution Retrofit electrical operated valve actuator, tying into existing infrastructure, without stopping production Results 16 producing wells are retrofitted with electric chokes 1900bbl/d increased production In operation since Dec.2001 Choke Control Unit (CCU) Choke Actuator Manifold Sand Detector and Clamp Unit Choke Bridge

14 Electric Control System configurations Manifold control System Components Tree control

15 Battery technology

16 Norne manifold project 16 Electrical actuators On manifold B+E and 8 XT chokes Electrical actuators on manifold D: 1 Piggingvalve + 8 branch valves 4 XT choke valves

17 Reference list electric actuator systems ~ 8,0 m 5,4 m 4,0 m Statfjord 2001 Norne 2006 BR Albacora choke actuators 12 choke actuators 21 actuators 8 manifold actuators Raw seawater inj. 1 pig loop valve actuator Additional: 1 injection valve Åsgard, 4 manifold valve functions Gjøa

18 Technology Demonstration with Alcatel February 2nd. and 3rd Objective: Demonstrate communication and power interfaces to Alcatel system using FMC all-electric equipment Demonstration of combined Alcatel-FMC equipment at Alcatel sites in UK and France: Power demo in United Kingdom 2nd Februar Communication demo in France 3rd Februar Performed tests: Electric Actuator and control module powered by Alcatel DC power system after 600km cable simulator FMC Topside and Subsea Equipment simulator ETU communicate over 600 km Alcatel Fiber system Remote operation of Actuator in London from remote location in Paris

19 Standard Telecom equipment (Alcatel) and FMC All Electric Control System Submerged Equipment and Cable Solutions Branching Unit FMC Electric System Optical Fibre cable Repeater Power Feed Eqipment Telecom technology from Alcatel over fiber with repeaters Enables high bandwith communication and power feed for low power system. FMC s All Electric Control System eliminates umbillical lines for hydraulics Stored energy in rechargeable batteries for high power valve actuation

20 Equipment-Power feed from Alcatel system Converter system from Alcatel Alcatel wer Feed Equipment 10 kv Power fed from land Alcatel converter: 10 kv DC V DC FMC converter 400 V DC til 375 V AC DC/DC Converter 10kV/400V Power To Templates Direct termination to cable Possible integration of converters ROV connectors

21 Power feed and Subsea control in London Demo #1 Objective: Provide power to subsea equipment from Alcatel system through 650 km cable simulator 10 kv DC 375 V AC.

22 Remote control and power control Paris London Demo #3 Objective: Demonstrate remote control of power controllers and subsea modules Same setup in London: etech equipment in London ETU and Power Feed Control station in Paris. Converter box in London, ethernet/serieconverter

23 Successful Test for Statoil in Greenwich and Paris - February 2006 Demonstrates the feasibility of 600 km remote subsea control High bandwidth (1 Gbps+) communication DC power transmission at a level compatible with an FMC electrical subsea systems for large field developments (10 60 kw) Electric actuators in Greenwich controlled from Paris! Pictures from demonstration at Alcatel, Greenwich, February

24 Staged Implementation Plan: Electric actuator systems E-LWI (hybrid) Choke control (Statfjord) Manifold valves (Norne) All-electric Production Systems Gas Compressor Surge Control 2010

25 Conclusion All electric control systems are gradually maturing in traditional field developments For ultra long step out projects, it represents an attractive solution for subsea field developments