SUBSEA POWER COMPONENTS

Installed motor shaft power

0,0

2,0

4,0

6,0

8,0

10,0

12,0

14,0

16,0

18,0

20,0

1997 2002 2003 2005 2006 2007 2009 2010 2011

MW

LU

FE

NG

TR

OL

L

TO

RD

IS

TY

RIH

AN

S

PA

ZF

LO

RAccumulated 2011 ~70 MW

Topside Subsea

VSD

M

M

HV grid50/60 Hz

App 7 kV0-200 Hz

Inputtransformer

Most common power supply systems

Topside SubseaVSD

M18-50 kV

Most (all so far) motors for subsea processing require variable speed drive (VSD) due to uncertainty in reservoir data, especially over the field’s life time

Subsea Power Supply Systems

Topside VSDs - AC

Topside

Subsea

M M M

VSD

Transformer

Motor

TransformerTransformer

Switchgear

M M MMotor

VSD

Subsea Distribution - AC

AC: Alternating Current DC: Direct Current

DC/VAC

AC/DC

M M MMotor

Subsea Distribution– DC?

Subsea Power Supply Systems – continued

Transformer

Switchgear

M M MMotor

VSD

AC/LFAC

Subsea Distribution - LFAC

16 2/3 Hz

Large transformers!

AC: Alternating Current DC: Direct Current LF: Low Frequency

Studies suggest 50 MW/600 km LFAC is feasible

Typical subsea power supply string

Power cable

Penetrator/Dry mate connector

Transformer

Motor penetrator

Wet mate connector Pump/motor

Typical pump station layout (2 pumps)

Electrical Motor

Power Jumper

Subsea Transformer

ElectricalConnectors

11 x 6.2 x 7.7 m

125 tons

Typical Pump/Motor unit – liquid cooled

• Shaft power rating : 300 - 3000 kW

• Rated voltage ≤ 6600 V

• App. 50 units installed

• App. 1.5 mill running hrs accumulated

• Installed in water depths up to 1800 m

• Liquid: mineral oil or water/glycol mix

Need for larger pump motors

identified by several

operators: 5-6 MW

Permanent magnet motor

under qualification (3 MW)

XLPE cable wound stator for water/glycol barrier fluid

Subsea Gas Compression –Statoil motor qualification programs

Ormen Lange

• Gas cooled

• 12.5 MW

• 6600 V

• 10670 rpm

Åsgard

• Gas cooled

• 8 MW

• 6200 V

• 11200 rpm

Gullfaks 2030

• Oil cooled

• 2 x 2.5 MW

• 6600 V

• 2 x 4500 rpm

Pump motor - 600 kW• PM rotor• Canned

CONNECTORS AND PENETRATORS

DRY MATE CONNECTOR

• For connection in dry/controlled environment

• Available with higher electrical rating (voltage)

Normally three main classifications:

WET MATE CONNECTOR

• For subsea connection

• Protection caps normally required when unmated

PENETRATOR

• Equipment bushing

• Available with high differential pressure rating and/or high electrical rating (voltage)

DMECPEN

WMEC

PEN

TYPICAL SUBSEA POWER JUMPER ARRANGEMENT

TYPICAL PUMP CONNECTOR ASSEMBLY

MALE

FEMALE

OUTER TANK

INNER TANK

UMBILICAL

TRANSFORMER MODULE

Subsea Transformer – Typical layout

• Oil filled/Pressure compensated

• Double sealing philosophy

• Natural cooling

• Minimum instrumentation

• 13 units in service

• 750 kVA 10.5/3.5 kV

• 1600 kVA 11/1 kV 85 Hz

• Tyrihans:

• 2 x 4000 kVA 22/6.9 kV 67.5 Hz

Subsea Transformer – ongoing qualifications

• Ormen Lange (Operator: Shell)

• 20/20 MVA 120/22 kV (Main transf) - Pilot

• 15 MVA 22/3.7/3.7 kV (Compr VSD transf)

• 750 kVA 22/2.85 kV (Pump VSD transf)

• Åsgard MF

• 15 MVA 38.25/6.2 kV – 200 Hz

• Jack St Malo (Operator: Chevron)

• 5 MVA, 22/ 6.6 kV – 67 Hz

* Operated by Shell

Tyrihans

Ormen Lange

• Electrical tests – IEC

• Thermal tests

• Component pressure tests

• Welding qualifications

• Vacuum test of housing

• Compatibility tests

• Compensator endurance tests

Subsea Transformer – testing

SUBSEA Variable Speed Drive (VSD)

Ormen Lange VSD modules(Converteam/Aker)Power: 12.5 / 0.4 MWVoltage: 6.6 / 2.5 kVForced coolingAtmospheric enclosure

SEPDIS VSD module(ABB/Framo/GE)Power: 3.5 MVAVoltage: 3 kVPassive coolingAtmospheric enclosure

Siemens power grid VSDPower: 6 MVAVoltage: 6.6 kVPassive coolingPressure compensated

Qualified(but..)

Qualification ongoing

SUBSEA SWITCHGEAR (Circuit Breaker)

Ormen Lange CB module• 36 kV• Atmospheric enclosure• Incl. UPS power supply• Incl. LV distribution• Incl. VSD pre-charge system• 900 m water depth

GE Vetco Gray • 24 kV• Oil filled, pressure

compensated base• Atmospheric breaker

chamber• 2000 m water depth• Shallow water tested

Siemens power grid SWG• 36 kV• Oil filled, pressure

compensated base• Atmospheric breaker

chamber (2 CB’s/chamber)• 3000 m water depth

Qualification ongoing

Current rating limited by penetrators/connectors!

Subsea Power Components

Steinar MidttveitLeading Advisor, Subsea Electrical Technologystmid@statoil.com, tel: +47 9516 8760www.statoil.com

Thank you