Multi Phase Flow Measurement By S.Manickarajan

What is Multi Phase Flow Meter ?

If the measurement fluid consists of more than one phase, the multiphase flow meter comes in present

Examples

• Product fluids such as crude oil from wells

• Steam and condensate flow

Why Multi Phase Flow Meter is required?

Water breakthrough detection Gas coning detection Gas lift optimisation Other optimisation considerations can be made for

chemical injection (e.g. methanol, demulsifier, etc.)

Custody transfer measurements for production fluid are the basis for money transfer, either between company and government or between two companies.

Water coning or Water breakthrough detection

When a layer of water under the oil layer channeling into the oil accumulation, it is called water breakthrough or water coning phenomena

Heterogeneous reservoir without inflow control evidences early water breakthrough.

Gas coning or Gas breakthrough detection

When a part of gas above the oil layer channeling into the oil accumulation, it is called Gas breakthrough or Gas coning phenomena

Heterogeneous reservoir without inflow control evidences early gas breakthrough.

Improving Lift Efficiency

Why Methanol Chemical Injection?

In order to avoid costly downtime due to freeze-ups of deep water well systems , chemicals such as Methanol are injected into each well as a preventive countermeasure.

The methanol Injection shall be decided by observing the water cut profile over a period for early identification of frozen of water

Types of Multi Phase Flow Meter

Separator based MPFM In line MPFM

Multi Phase Flow Meter -Separator Method

Principle

The flow rates of well fluids have been measured by separating the phases by separators

Measuring the outputs of the separated fluids by conventional single-phase techniques

e.g., orifice plates for gas and turbine meters for oil.

Multi Phase Flow Meter -Separator Method

Bulk in Size High Installation cost

Disadvantages

Accuracy depends on separation efficiency

Constraints

The volumetric flow rate Q =A (α vg + β vw +χ vo) where A is the cross-sectional area of the pipe.Since α + β + χ = 1, only two of the phase fractions (usually gas void fraction α and

water fraction β) need to be measured. Q =A {α vg + β vw +[1- (α + β)] vo }with five independent measurements required to determine the total volumetric Flow

rate of the mixture.The mass flow rate M of the three-phase mixture is given byM =A {α vg Dg + β vw Dw +[1- (α + β)] vo Do } with eight independent measurements required to determine the total mass Flow

rate of the mixture.

In line MPFM

Principle

In line MPFM

Block Diagram

Volume fractions of the individual phases are dynamic and varying in patterns

Challenges in In line MPFM

Challenges in In line MPFM

Significant variation in the PVT properties leads to water at different phases

Challenges in In line MPFM

Salinity changes the density of water

Challenges in In line MPFM

Velocities of individual phases are different due to different in viscosities

Component volume fraction measurements

Capacitance

Conductance

Component volume fraction measurements

Single/Multiple gamma ray Absorption

Component volume fraction measurements

Microwave Propagation

Velocity measurements

Cross correlation techniques Acoustic attenuation Coriolis device Dual Venturi Positive displacement device

Cross-Correlation Techniques

• Assume that the phases fractions pattern remains unaltered as it travels between the sensors

• The output signal generated by the downstream sensor will then be a time-delayed replica of the upstream sensor's output.

Acoustic Speckle Cross-Correlation Techniques

• When an oscillating excitation force is applied to the tube causing it to vibrate; the tube will vibrate at its natural frequency which depends upon the linear density.

• With the measurement of the vibrating frequency, density of the fluid stream can be accurately obtained.

• The fluid flowing through the tube will induce a rotation or twist which is directly affected by the mass passing through the tube. Hence mass flow rate shall be measured.

Principle of Coriolis flow meter for 2 Phase Measurement at MPT - Aishwarya PLR

Principle of Coriolis flow meter for 2 Phase Measurement at MPT - Aishwarya PLR

By conservation of Mass MW + MO = ML

QW X DW + QO X DO = QL X DL

Where DL is density of total liquid measured by coriolisis meter Do is density of oil to be configured Dw is density of water to be configured

Let WC is the water cut, thenQL X WC X DW + QL X(1-WC) X DO = QL X DL

QL X WC X DW + QL X DO –WC X QL X DO = QL X DL

QL X WC X DW + QL X DO –WC X QL X DO = QL X DL

WC X DW + DO –WC X DO = DL

WC X DW–WC X DO = DL - DO

WC X ( DW– DO ) = DL – DO

WC = (DL – DO ) / ( DW– DO ) And henceQW = WC X QL Where QL –Total Liquid Volume measured by CoriolisisQO = (1-WC) QL

Principle of Coriolis flow meter for 3 Phase Measurement at MPT - Bhagyam PLR

P 0P 1

P 3P 6P 4 P5

Coriolis mass flow meter• Fluid mixture mass flow rate(Mt)• Fluid mixture density(Dt)• Fluid mixture volumetric flow rate(Qt)

Dual venturi meter• To measure Gas fraction (α)

Agar OW-200 water cut meter• Water Concentration in fluid mixture

Agar ID-201 interface detector• Determine Water Continuous or Oil

Continuous

Pressure transmitters• P0 - Inlet Pressure of MPFM• P1 - DP across coriolisis• P2 - DP across higher range throat• P3,P6 - DP across lower range throat• P4 - DP across dual venturi to measure viscous loss• P5 - DP across MPFM

P 2

• When an oscillating excitation force is applied to the tube causing it to vibrate; the tube will vibrate at its natural frequency which depends upon the linear density.

• With the measurement of the vibrating frequency, density of the fluid stream can be accurately obtained.

• The fluid flowing through the tube will induce a rotation or twist which is directly affected by the mass passing through the tube. Hence mass flow rate shall be measured.

Principle of Coriolis flow meter for 3 Phase Measurement at MPT - Bhagyam PLR

• By conservation of Mass M1=M2

Applying Bernoulli’s Theorem for Ventury 1&2• δ1dp1=δ2dp2

• V1/V2=δ1dp1/δ2dp2

• V2/V1=δ2dp2/δ1dp1

• V1=Vo1+Vw1+Vg1 and V2=Vo2+Vw2+Vg2

• At 1 and 2 Water volume will not change since water is assumed as non-compressible

• Vw2=Vw1 • Vo2=Vo1-(ε)Dp*Vo1 Where ε is shrinkage factor of oil as gas in the oil is liberated• Vg2=(Vg1*Cg* dp)+(δRs*Vo1) where δRs is the volume of the gas liberated

by oil per unit volume and Cg is expansion co-efficient of gas

Dual venturi meter

D1 D2d1 d2

dp1 dp2

Fig.1• Dual Venturi Meter• Water fraction requires two sensors

30a,30b.• 30a measures permittivity when oil or gas

forms continuous phase.• 30b measures effective resistivity when

the water forms a continuous phase

Fig.2• Dual Venturi Meter with Choke

Fig.3• Dual Venturi Meter but Water Fraction

Sensors at 2nd venturi out

Dual venturi meter

Component volume fraction measurements

Microwave Propagation

Agar ID-201 interface detector

• A radiofrequency signal is provided by the electronic control and radiated by an antenna.

• Water in the interface absorbs the radiated energy due to its conductive nature, but hydrocarbon will not.

• The amount of absorbed energy is measured by the electronic control and a 4-20mA is generated proportionally to that absorption.

Principle of Agar MPFM

Calculation in Agar MPFM

• QT = MT/ DT , Where MT Mass flow rate of Gas and Liquid mixture and DT Density of Gas and Liquid mixture are Measured by Coriolisis Meter By conservation of Mass

ML + MG = MT

QL X DL + QG X DG = QTX DT Where DL is density of liquid (Oil & Water) DG is density of gas (1- α ) X QT X DL + α X QT X DG = QTX DT

(1- α ) X QT X DL + α X QT X DG = QT X DT

(1- α ) X DL + α X DG = DT

DL - α X DL + α X DG = DT

α X (DG – DL ) = DT – DL

α = (DT – DL ) / ( DG– DL )By conservation of Mass MW + MO = ML

QW X DW + QO X DO = QL X DL Where Do is density of oil to be configured Dw is density of water to be configuredLet CW is the water cut, then

QL X CW X DW + QL X(1- CW) X DO = QL X DL

QL X CW X DW + QL X DO –CWC X QL X DO = QL X DL

QL X CW X DW + QL X DO –CW X QL X DO = QL X DL

CW X DW + DO –CW X DO = DL

DL = CW X (DW –DO ) + DO

α = (DT– DO – CW X (DW –DO )) / ( DG– DO – CW X (DW –DO )) α = (DT– DO – CW X (DW –DO )) / ( DG– DO ) as CW X

(DW –DO ) in Numerator negligible

Calculation in Agar MPFM

• Qt = Mt / Dt , Where Mt Mass flow rate of Gas and Liquid mixture and Dt Density of Gas and Liquid mixture are Measured by Coriolisis Meter

(Dt-Do)-Cw(Dw-Do) is calculated as gas void fraction from Dual Venturi • α = Diff.Pressure , Pressure and Temperature Transmitters

(Dg-Do)

• Qg = α Qt ,

• Ql = (1-α) Qt Where Ql is Calculated Liquid Volumetric flow rate

• wc = (1-α) Cw Where Cw is Water concentration measured by Water cut meter OW200

• Qw = wc Ql Where wc is Calculated Water cut from above

• Qo = (1-wc) Ql Where Qo is Calculated Oil Volumetric flow rate

Calculation in Agar MPFM

MPFM installed in Mangala & Aishwarya

: :

Make Model Location

AGAR MPFM-50 Bhagyam Header Line

Schlumberger Phase watcher VX MPT and Aishwarya Wellpads test header

Haimo MFM-2100/M-3 MPT Wellpads test header

Emerson Model 3700 Aishwarya PLR

Commercial Inline MPFM

Manufacturer Meter Phase concentration measurement

Phase velocity measurement

Agar Corporation Inc. MPFM 50 Microwave CoriolisAker Solutions ASA DUET Dual energy gamma Cross correlationJiskoot Quality Systems Mixmeter Dual energy gamma Pressure drop across an in-line

mixer

MEDENG Ltd MD 04 Flow modelling from primary sensor output signals

Flow modelling from primary sensor output signals

Multi Phase Meters AS MPM Single energy gamma/high frequency electromagnetic waves

Venturi

Neftemer Ltd   Multi energy gamma Analysis of primary sensor output signal

Petroleum Software Ltd ESMER Flow modelling from primary sensor output signals

Flow modelling from primary sensor output signals

Commercial Inline MPFM

Manufacturer Meter Phase concentration measurement

Phase velocity measurement

Pietro Fiorentini S.p.A. Flowatch 3I Impedance Cross correlation/Venturi

  Flowatch HS Single energy gamma/impedance

Cross correlation/Venturi

Roxar Flow Measurement

MPFM 2600 Impedance Cross correlation/Venturi

  MPFM 2600 GammaSingle energy gamma/impedance

Cross correlation/Venturi

  Subsea MPFM Single energy gamma/impedance

Cross correlation/Venturi

  MPFM 1900VI Single energy gamma/impedance

Cross correlation/Venturi

  MPFM 1900VI Non-gamma

Impedance Cross correlation/Venturi

Schlumberger Ltd Phasewatcher Dual energy gamma Venturi  Phasetester Dual energy gamma VenturiTEA Sistemi S.p.A LYRA Single energy

gamma/impedanceVenturi

References

1. M.J. Berger, J. H. Hubbel et al., XCOM Photon Cross Section Database, National Institute of Standards and Technology

2. Hans R E van Maanen, Shell Global Solutions, Measurement of the Liquid Water Flow Rate Using Microwave Sensors in Wet-Gas Meters: Not As Simple As You Might Think, North Sea Flow Measurement Workshop 2008.

3. J.P. Couput, G. Salque, P. Gajan, A. Strzelecki, J.L. Fabre, New Correction Method For Wet Gas Flow Metering Based on Two Phase Flow Modelling: Validation on Industrial Air/Oil/Water Tests at Low And High Pressure, North Sea Flow Measurement Workshop 2007.

4. R. de Leeuw, Liquid Correction of Venturi meter Reading in Wet Gas Flow, North Sea Flow Measurement Workshop 1997

5. M. van Werven, H. R. E. van Maanen Modelling Wet Gas Annular/Dispersed Flow Through a Venturi AIChE Journal , June 2003, Vol. 409, No. 6

6. A Wee, H Berentsen, V.R. Midttveit, H. Moestue, H.O. Hide, Tomography powered multiphase and wetgas meter providing measurements used for fiscal metering, North Sea Flow Measurement Workshop 2007.

7. Handbook of Multiphase Flow Metering, Rev. 2, March 2005, Tekna8. MPM Meter Qualification – MPM White Paper No. 49. Water Salinity Measurement & Auto Configuration – MPM White Paper No. 210.A.Wee, I. M. Skjældal, Ø. L. Bø, Multiphase metering with early detection of changes in water salinity – Americas

Workshop, 200911. Ø. L. Bø, A. Wee, I.M. Skjældal, Tomography powered 3-phase flow metering in the wet gas regine, 8th International

South East Hydrocarbon Flow Measurement Workshop, March 200912.MPM Droplet Count, MPM White Paper No. 713.United States Patent for Dual Venturi Multiphase flow meter.

ANY QUESTIONS?