electrical engineeing

7/30/2019 ELECTRICAL ENGINEEING

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20082008

Texas A&M UniversityTexas A&M University

2424thth International Pump UsersInternational Pump Users

SymposiumSymposium


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Multiphase PumpingMultiphase Pumping

By: Bob Heyl


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Presentation ContentsPresentation Contents

Definitions and Criteria: Multiphase Flow, GasDefinitions and Criteria: Multiphase Flow, GasVolume (Void) Fraction (GVF) and CriteriaVolume (Void) Fraction (GVF) and Criteria

Types of Multiphase PumpsTypes of Multiphase Pumps

General ApplicationsGeneral Applications

Advantages and Disadvantages of DifferentAdvantages and Disadvantages of DifferentTypes ofTypes of MPPsMPPs

Specific ApplicationsSpecific Applications

Sample EconomicsSample EconomicsReasons to Use OffshoreReasons to Use Offshore

Subsea DevelopmentsSubsea Developments


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Definitions and CriteriaDefinitions and Criteria


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What is Multiphase Flow?What is Multiphase Flow?

Flow consisting of at least:Flow consisting of at least:

-- LiquidLiquid

-- GasGas

(But often high volumes of gas, mixed with(But often high volumes of gas, mixed with

oil, water, and solids)oil, water, and solids)


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MutiphaseMutiphase Pump CriteriaPump Criteria

Gas Volume (Void) Fraction [GVF] at Suction ConditionsGas Volume (Void) Fraction [GVF] at Suction Conditionsmeasured in %measured in %

ParticulateParticulate -- measured in %measured in %Maximum Particle Size and DistributionMaximum Particle Size and Distribution

Liquid ViscosityLiquid Viscosity

TemperatureTemperatureGas CompositionGas Composition

Suction PressureSuction Pressure

Discharge PressureDischarge Pressure

Flow RateFlow Rate

Potential for Slug FlowPotential for Slug Flow


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GVF for GasGVF for Gas--OilOil--Water MixturesWater Mixtures

Need: Oil Rate in BPDNeed: Oil Rate in BPD

Gas Rate in SCFDGas Rate in SCFD

Water Rate in BPDWater Rate in BPD

Pump Inlet Pressure in PSIGPump Inlet Pressure in PSIGPump Discharge Pressure in PSIGPump Discharge Pressure in PSIG


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Actual BPD of Gas =Actual BPD of Gas =

(ACFD) (7.481 gal/cu ft)(1 bbl/42 gal) =(ACFD) (7.481 gal/cu ft)(1 bbl/42 gal) =(ACFD) (0.178 bbl/cu ft.)(ACFD) (0.178 bbl/cu ft.)

wherewhere

ACFD = [(SCFD) (14.7ACFD = [(SCFD) (14.7 psiapsia) (MPP Inlet Temp) (MPP Inlet Temp

F+460) (Z)]/[(MPP Inlet PressF+460) (Z)]/[(MPP Inlet Press psiapsia) (520R)]) (520R)]

where Z is often 1.0where Z is often 1.0


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BPD = (Actual BPD of Gas + BPD of Oil +BPD = (Actual BPD of Gas + BPD of Oil +

BPD of Water )BPD of Water )

And thereforeAnd thereforeGVF = (Actual BPD of Gas)/(BPD)GVF = (Actual BPD of Gas)/(BPD)


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Types of Multiphase PumpsTypes of Multiphase Pumps


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Types of Artificial Lift andTypes of Artificial Lift and

Multiphase Pumps (MPPs)Multiphase Pumps (MPPs)

Electric Submersible Pumps (ESPElectric Submersible Pumps (ESPs)s)

RotordynamicRotordynamic

Progressive Cavity Pumps (PCPProgressive Cavity Pumps (PCPs)s) -- PositivePositiveDisplacementDisplacement

HelicoHelico--Axial PumpsAxial PumpsRotordynamicRotordynamic

CentrifugalCentrifugal

TwinTwin--ScrewScrewPositive DisplacementPositive Displacement


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Electric Submersible Pumps (Electric Submersible Pumps (ESPsESPs))


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Progressing Cavity Pumps (PCPs)Progressing Cavity Pumps (PCPs)


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Progressing Cavity Pumps (PCPs)Progressing Cavity Pumps (PCPs)


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MPP7-stage helico-axial

125,000 bpd700 hp motor w/ VFD (3600 rpm)

HelicoHelico--AxialAxial


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HelicoHelico--Axial PumpAxial Pump

BEARINGS

MECHANICAL SEAL


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HelicoHelicoAxial Rotor AssemblyAxial Rotor Assembly


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Buffer TankBuffer Tank

BUFFERTANK INLET

BUFFERTANK

OUTLET

BUFFER TANK DRAIN


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HelicoHelico--Axial Subsea PumpAxial Subsea Pump


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Hydraulic CentrifugalHydraulic Centrifugal

Special design ofSpecial design of helicohelico--axial pump with aaxial pump with a

multistage hydraulic turbine fed by amultistage hydraulic turbine fed by aremote high pressure pumpremote high pressure pump

Turbine and pump integrated on aTurbine and pump integrated on acommon shaft in a cartridge barrel casingcommon shaft in a cartridge barrel casing


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Hydraulic CentrifugalHydraulic Centrifugal


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Hydraulic Centrifugal SubseaHydraulic Centrifugal Subsea

PumpPump


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TwinTwin--ScrewScrew

500 HP

125,000 BPD@1925 RPMVFD to 2300 RPM


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TwinTwin--Screw: ScrewsScrew: Screws


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TwinTwin--Screw: ScrewsScrew: Screws


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Twin-Screw: Screws in Pump Case


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TwinTwin--Screw: MaintenanceScrew: Maintenance


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Twin-Screw: Liner in Pump Case


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TwinTwin--Screw: Timing GearsScrew: Timing Gears


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MPP DrivesMPP Drives

Usually Motors withUsually Motors with ASDsASDs, especially for Positive, especially for Positive

Displacement Pumps (PCPs and TwinDisplacement Pumps (PCPs and Twin--Screws)Screws)

Engines (Natural Gas, Diesel)Engines (Natural Gas, Diesel)

Hydraulic TurbinesHydraulic Turbines


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General ApplicationsGeneral Applications


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Upstream ApplicationsUpstream Applications

Eliminate Flaring at Reduced CostEliminate Flaring at Reduced Cost Reduce Backpressure at WellheadReduce Backpressure at Wellhead

and Increase Production at Wellheadand Increase Production at Wellhead

Pump Gas & Liquid Mixtures up toPump Gas & Liquid Mixtures up to100% GVF (usually designed for100% GVF (usually designed forspecific time periods)specific time periods)

Reduced Installed CostReduced Installed Cost vsvs TraditionalTraditionalSystemsSystems


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Downstream ApplicationsDownstream Applications

Flare KO DrumsFlare KO Drums

Any Highly Gaseous Liquid StreamAny Highly Gaseous Liquid Stream Replace Centrifugal Pumps that HaveReplace Centrifugal Pumps that Have

Cavitation Problems Due to ExcessiveCavitation Problems Due to ExcessiveGasGas


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Advantages and DisadvantagesAdvantages and Disadvantages

of Different Types of MPPsof Different Types of MPPs


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ESPsESPs

GENERAL CHARACTERISTICS OF MULTIPHASE PUMPS

ESPs

PUMP ADVANTAGES DISADVANTAGES

Electric SubmersiblePumps (ESPs)

Rotodynamic

Traditionally down-hole andsubmersible, but can be used on the

surface If solids, potential erosion

Primarily UpstreamApplications Good for low viscosity liquids Cant handle higher viscosities

Speed 3600 rpm, Flowrates to 200,000BPD No higher than 65% GVF

Low cost High shear - potential emulsions

Can handle higher temperatures Installed Units: Normal MTBF of 3 years

Gas conditioners to 40% (65%) GVF


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PCPsPCPs


PCPs


Progressing Cavity

(PCPs)PD Down-hole, submersible or surface Elastomer problems above 300 F

Upstream orDownstreamApplications Handles some solids Contacting rotor and stator

1450 PSI differentials Can't run dry

Speed: 1800 rpmFlowrates: up to 11,000 BPD

Can run higher viscositiesRelatively low shear

GVF 35% (100%)


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HelicoHelico--AxialsAxials


Helico-Axials


Helico-Axial

Rotodynamic Down-hole, surface, or submersible If solids, potential for erosion?

Upstream orDownstream High speed: 4000-6800 rpm High sheer

Flowrates up to 560,000 BPD

Differential Pressures up to 1125 psi

Can achieve up to 100% GVF

TwinTwin--ScrewsScrews


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TwinTwin-ScrewsScrewsGENERAL CHARACTERISTICS OF MULTIPHASE PUMPS

Twin-Screws


Twin-ScrewPD

Surface, down-hole (incommercialization by one supplier), orsubmersible (in commercialization) Surface Pump with 4 mechanical seals

Upstream orDownstream

Speed: Low to high speedFlowrates: up to 440,000 BPD (surfacepumps)

Can achieve up to 100% GVF fordesigned time periods

Can run higher viscosities

Can run high temperatures

Low shear

Low NPSHr

Can run dry, non-contacting rotor andstator

1400 psig differentials

Particulates to 0.5 wt. %

S f


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Specific Applications bySpecific Applications by

ChevronChevron


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Sample List of Chevron ApplicationsSample List of Chevron Applications

Texas: HumbleTexas: HumbleSurface TwinSurface Twin--ScrewScrew

Indonesia: Minas andIndonesia: Minas and DuriDuriSurface TwinSurface Twin--ScrewScrew

30 to 100% GVF30 to 100% GVF

Chad: Various FieldsChad: Various FieldsSurface TwinSurface Twin--ScrewsScrews

38% to 56% GVF38% to 56% GVF

Great Britain: CaptainGreat Britain: CaptainHydraulic DriveHydraulic Drive HelicoHelico--AxialAxial


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Sample List of Chevron ApplicationsSample List of Chevron Applications

Venezuela:Venezuela: BoscanBoscan -- Surface TwinSurface Twin--ScrewsScrews

40% GVF40% GVF

Venezuela:Venezuela: HamacaHamaca -- DownDown--hole PCPshole PCPs

-- Surface TwinSurface Twin--ScrewsScrews

92% GVF92% GVF

California: Midway SunsetCalifornia: Midway Sunset -- Surface TwinSurface Twin--ScrewsScrews

59 to 90% GVF59 to 90% GVF

California: Midway SunsetCalifornia: Midway Sunset -- Surface TwinSurface Twin--ScrewScrew

-- Charge to heaterCharge to heater treatertreater

-- Slugs of 100% GasSlugs of 100% Gas


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HumbleHumbless TwinTwin--Screw PumpScrew Pump

Indonesia LOSF Multiphase PumpsIndonesia LOSF Multiphase Pumps


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Collect and boost 95% GVF

Stream to Eliminate Flaring

Indonesia LOSF Multiphase PumpsIndonesia LOSF Multiphase Pumps

Indonesia: Light Oil SteamIndonesia: Light Oil Steam


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60,000 BPD

250 hp motor, 4 poles

460V VFD

API plan 32 seal flush

Enlarged bearing

housing

Air-cooling for bearing

lube oil cooling; with

blower installed at

coupling hub Borided screws

6 chambers screws

Stellite 12 welded on

liner ID

Indonesia: Light Oil SteamIndonesia: Light Oil Steam

Flood (LOSF) TwinFlood (LOSF) Twin--ScrewsScrews


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Natural sand build-up oninlet section

No evidence of sand

accumulation inside liner

Stellite Liner: 65 HRC

Indonesia: Twin-Screws and Sand


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California: Midway Sunset TwinCalifornia: Midway Sunset Twin--ScrewScrew


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Chad: TwinChad: Twin--ScrewsScrews


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California: Multiphase Pump SolutionCalifornia: Multiphase Pump Solution

).

Discharge

Piping


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TwinTwin--Screw: Subsea PumpScrew: Subsea Pump


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TwinTwin--Screws and ParticulateScrews and Particulate

C B T h l


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Current Best TechnologyCurrent Best Technology

TwinTwin--Screw: ScrewsScrew: Screws nitridednitrided oror boridedborided to depthto depthof 0.003of 0.003

TwinTwin--Screw: CasingScrew: Casing designed with replaceabledesigned with replaceable

linerliner

TwinTwin--Screw: LScrew: Liner coated with tungsten carbideiner coated with tungsten carbide

oror StelliteStellite 1212

HelicoHelico--Axial impellers coated withAxial impellers coated with MetcoMetco SUMESUME


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Mechanical SealsMechanical Seals

Use correct API flush planUse correct API flush planUse correct seal facesUse correct seal faces

Hard Particulate: hard face vs. hardHard Particulate: hard face vs. hardfaceface

Softer Particulate or none: carbon vs.Softer Particulate or none: carbon vs.

tungsten or silicon carbidetungsten or silicon carbide


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Multiphase production and the installation costs ofMultiphase production and the installation costs of

the traditional system demands simpler andthe traditional system demands simpler and

smaller installation and a more cost effectivesmaller installation and a more cost effectiveproduction system.production system.

Twin Screw multiphase pumping application inTwin Screw multiphase pumping application in

heavy oil steam flood in sandy environment isheavy oil steam flood in sandy environment is

proven to be feasible.proven to be feasible.

To date, operational reliability satisfies if notTo date, operational reliability satisfies if not

exceeds acceptable industrial standard.exceeds acceptable industrial standard.

Indonesian ExperienceIndonesian Experience


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Sample EconomicsSample Economics

M l i h I ll i Ad


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Multiphase Installation AdvantagesMultiphase Installation Advantages

MPP

Wellhead

MultiphaseLineWellhead

Gas line

Oil line

MultiphaseTraditional Separation


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MULTIPHASE BOOSTINGMULTIPHASE BOOSTING

Pressure

Flowrate

Boosted WHFP

Unboosted WHFP

Flowline losses

P

Q


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Typical Production IncreasesTypical Production Increases

Production Increase Due toProduction Increase Due to


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Production Increase Due toProduction Increase Due to

Reduced Backpressure on WellsReduced Backpressure on Wells


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DuriDuri Production Increases with MPPsProduction Increases with MPPs

Multiphase Pump Field Trial - Duri Field 1998

Oil Production at Duri Area 6 SouthEast Quadran

8,000

9,000

10,000

11,000

12,000

13,000

14,000

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98/07/07

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Oil

Production

(18d

eg

API),

BOPD

Twinscrew MPP Test

Oct 5 - Nov 6Heli coaxial MPP test

Nov 23 - Dec 20

Reasons to Use MPPs Offshore (orReasons to Use MPPs Offshore (or


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Reasons to Use MPPs Offshore (orReasons to Use MPPs Offshore (or

Onshore)Onshore)No need to have separation vesselNo need to have separation vessel

One MPP vs. liquid pump and gasOne MPP vs. liquid pump and gascompressorcompressor

Smaller installed footprint (especially forSmaller installed footprint (especially foroffshore rigs)offshore rigs)

Less weight (especially for offshore rigs)Less weight (especially for offshore rigs)

One COMBINED liquid/gas line (especiallyOne COMBINED liquid/gas line (especially

for offshore rigs and Subsea installations)for offshore rigs and Subsea installations)


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Subsea DevelopmentsSubsea Developments


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Multiphase Pumps: Subsea EffortsMultiphase Pumps: Subsea Efforts

TwinTwin--Screw:Screw: One Commercial ApplicationOne Commercial Application

HelicoHelico--Axial:Axial: Approximately 25 ApplicationsApproximately 25 Applications

Hydraulic TurbineHydraulic Turbine HelicoHelico--Axial:Axial: Several in NorthSeveral in North

SeaSea


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SummarySummary

MPPs have been used to pump multiphaseMPPs have been used to pump multiphase

fluids that have:fluids that have:

-- Temperatures from ambient to 300FTemperatures from ambient to 300F

-- Suction pressures from 6 psigSuction pressures from 6 psig

-- Discharge pressures to 2000 psigDischarge pressures to 2000 psig

-- GVFGVFss to 100% (for designed time periods)to 100% (for designed time periods)

-- Particulate concentrations to 0.5 wt.%Particulate concentrations to 0.5 wt.%-- Almost any viscosityAlmost any viscosity


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SummarySummary

MPPs have been used to:MPPs have been used to:

-- Eliminate Flaring at Reduced CostEliminate Flaring at Reduced Cost-- Reduce Backpressure at WellheadReduce Backpressure at Wellhead

-- Increase ProductionIncrease Production

-- Pump with Low Shear & DecreasedPump with Low Shear & DecreasedEmulsion FormationEmulsion Formation

-- Pump with Low NPSHAPump with Low NPSHA

-- Reduce Installed Cost and MaintenanceReduce Installed Cost and MaintenanceCostsCosts vsvs Traditional SystemsTraditional Systems


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The EndThe End

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