Deep Submersible MotorsDeep Submersible MotorsWhatWhat’’s possibles possible

Hayward Tyler Ltd Group Technical DirectorKen Sears

Subsea Europe 200830 October, London

Progressive innovationProgressive innovation

1908 First submersible (water filled)

electric motor

“Gold Medals awarded

Paris 1878Calcutta 1884London 1884”

Technology developmentTechnology development......

BCPBCP’’ss to Subseato Subsea

Wet Stator Glandless Motor Pump

1948…Remains industry

standard! Submersible motorSWLP, FWP

Subsea motor

The case for Subsea The case for Subsea processingprocessing……

Sea Water Injection

Crude Oil Boosting

Produced Water Re-Injection

Multi Phase Pumping

Separation

Benefits of subsea pumpingBenefits of subsea pumping

Time

Value

Normal production capability

Improved productivity through pumping

Time

Value

Normal production capability

Additional production accessiblethrough pumping

“Installing subsea pumps close to wellheads may increase the total recovery rate for subsea wells by up to 25%

when compared with unboosted production” (Aker Solutions)

General Subsea Motor General Subsea Motor requirementsrequirements……

High VoltageUp to 11kV

Variable speedUp to 4000 rpm

CompactHigh casing pressures

Suitable for 3000m

Fully compliant to Oil Industry StandardsIEC 60034NorsokOil Company StandardsAPI 610

Ultra high reliabilityProven technologyConservative design

Fully compliant to Oil Industry Standards

Deep Submersible motorsDeep Submersible motors

0

1000

2000

3000

4000

5000

6000

7000

8000

1990 1995 2000 2005 2010 2015 20200

1000

2000

3000

4000

5000

6000

7000

8000kW Depth (m)

kW

Depth (m)

19921992

•

Kvaerner boosting station•

350kW

•

500m

19991999

•

EniAGIP

multiphase pumping •

2.5MW

•

1000m depth•

120 bar int. 95 bar ext

•

9kV (operating) 11kV (specification) VSD•

3m x 1.01m dia

12.8 tonnes

•

Superduplex

materials

20022002

•

Subsea mud pump•

935kW

•

2300m depth•

6.6kV VSD

•

3m x 1.2m dia

7.15 tonnes•

Superduplex

materials

20082008

•

Subsea water injection pump•

2.5MW

•

3000m depth•

6.6kV

•

VSD super synchronous•

2,500 to 4,000 rpm

•

3.3m x 1.2m dia•

12.4 tonnes

•

Superduplex

materials

Tyrihans SRSWI ProjectTyrihans SRSWI Project

Increased oil recovery Power supplied from Kristin Platform over 30 km awayVariable Frequency Drive (VSD) system at Kristin Subsea step-down transformers adjacent to the modules2 AKS LiquidBooster™ modules

AKS 8-stage centrifugal pump Hayward Tyler 2.5 MW motor

Platform over 30 km away

s adjacent to the modules

SRSWISRSWI == SSubseaubsea RRawaw SSeaea WWaterater IInjectionnjection

Technical risk managementTechnical risk management

Performance prediction

Insulation capability

Penetrator

Starting conditions

Thrust bearing life

Coolant circulation pump

Thermal stability

Material compatibility

Motor functional requirements Motor functional requirements ……

Rated power (shaft output) 2500 kWMax current 320 AOperating speed range 2500-4000 rpm Rated voltage / frequency 6.6 kV / 60 HzWinding insulation level 11 kVCasing internal design pressure ΔP 150 bar Casing external design pressure ΔP 30 bar Design lifetime 20 year (minimum)Time between intervention Minimum 5 yearMaximum total thrust (standstill) 46 kN Min seawater temperature +1 ºCMax seawater temperature +10 ºC Max pit water temp during testing +25 ºC

Rated power (shaft output)Rated power (shaft output)Max currentMax currentOperating speed rangeOperating speed rangeRated voltage / frequencyRated voltage / frequencyWinding insulation levelWinding insulation levelCasing internal design pressure Casing internal design pressure ΔΔPPCasing external design pressure Casing external design pressure ΔΔPPDesign lifetimeDesign lifetimeTime between interventionTime between interventionMaximum total thrust (standstill) Maximum total thrust (standstill) Min seawater temperatureMin seawater temperatureMax seawater temperatureMax seawater temperatureMax pit water temp during testingMax pit water temp during testing

Multi disciplinary engineering Multi disciplinary engineering challengeschallenges

Electrical analysis

Internal hydraulic losses

Thermal analysis

Rotor dynamics analysis

Bearing analysis

Casing Stress analysis

Shaft deflection analysis

Cooling system analysis

Electrical losses

Hydraulic Design of cooling pump Radial & Axial Thrust analysis

Rotor dynamics analysis

Shaft deflection analysis

Electrical losses

Oil Oil vsvs

Water/Glycol filled Water/Glycol filled TechnologyTechnology

Oil

High viscosityHigh frictional losses particularly at higher speeds

High dielectric propertiesStandard industrial motor insulation

Higher operating tempsCan lead to increased corrosion

Seawater ingress leads to immediate catastrophic failure

Water / Glycol

Low viscosityLower frictional lossesHigher speeds possible

Good dielectric propertiesFully insulated cables & joints

Cooler operation Corrosion inhibiting

Seawater ingress does not cause immediate failure

Water / Glycol is a commonly used control fluid

Environmentally friendly

Motor descriptionMotor description……....

3.3 m

12400 kg

Pressure CasingPressure Casing

Machining of Outer casing

Stator shell and windingsStator shell and windings

XLPE insulated cables and joints

Bearing Design Bearing Design –– Tilting Pad Tilting Pad JournalsJournals

“Stiff” radial bearings

High Voltage PenetratorHigh Voltage Penetrator

Power supply: Crossing the pressure boundary

Junction box & Junction box & compensatorcompensator

Coolant circulation pumpCoolant circulation pump

High efficiency impeller

Cooling CoilsCooling Coils

Spiral Heat Exchanger

6 parallel circuits

0102030405060708090

100

0 2 4 6 8 10 12

Design iterations Design iterations ……..

Length LLength LDiameter dDiameter d

High

sha

ftde

flect

ions

&Cr

itica

l Spe

edpr

oble

ms

UnbalancedMagnetic Pull

L/d ratioL/d ratio

Mot

or E

ffici

ency

Mot

or E

ffici

ency

Design iterations Design iterations ……..

Length LLength LDiameter dDiameter d

Predicted Performance DataPredicted Performance Data

Some of the many Qualification Some of the many Qualification TestsTests……

Penetrator Vibration TestsPenetrator Vibration TestsThrust Bearing performance and endurance tests

Coolant pump tests

and endurance testsThrust Bearing performance

Factory Full Load Performance Factory Full Load Performance TestsTests

Header TankElectrical Supply Cables

Fluid Pressure/Temp Transmitters Here

Load Machine

Epicyclic “Motor” Drive

Epicyclic Gearbox

Flow

FlowmeterPump & Fluid Storage For Filling System

ConclusionsConclusions

Motor Technology is now catching up with the demand for Subsea drivesQualified machines2500 kW at speeds up to 4000 rpm a proven realityDesigns suitable for 11kV voltage spikesDesigns suitable for 3000m depth waterWater/glycol filled motors provide proven reliabilityScaleable designs valid for higher powers and speeds

Customer & Supplier Customer & Supplier partnershipspartnershipsCustomer & Supplier Customer & Supplier Customer & Supplier Customer & Supplier Customer & Supplier partnershipspartnershipspartnershipspartnershipspartnerships

Deep Submersible motorsDeep Submersible motors

0

1000

2000

3000

4000

5000

6000

7000

8000

1990 1995 2000 2005 2010 2015 20200

1000

2000

3000

4000

5000

6000

7000

8000kW Depth (m)

?

Deep Submersible MotorsDeep Submersible MotorsWhatWhat’’s possibles possible

Hayward Tyler Ltd Group Technical DirectorKen Sears

Thank YouThank You