PETE 532

Well Performance

Inflow Performance

Relationships (IPR)

for Special Cases

IPR for Special Cases

Waterflood Wells

Vertical Wells with Stratified Formations

Horizontal Wells with Reservoir Zonation

Multilateral Horizontal Sections

Multilateral/Horizontal Wells with ICD or

ICV

IPR for Waterflood Wells

If we have rate test:

Use Vogel for Pwf<Pb

Use straight line for Pwf≥Pb

If no rate test:

IPR can be estimated by:

0.00708

ln 0.472 / '

ro rw

o o W We w

K KkJ

B Br r S

h

Qt= Qo+Qw

IPR for Stratified Reservoir

Two production zones

Commingled production

PR2>PR1

When Pwf is > PR1 Liquid will flow into zone 1

No NET Production until Pwf is low enough so

that flow from the high press zone is more

than the rate into the low press zone

This press value must be determined (P*wf)

IPR for Stratified Reservoir

*

2 2 2

*

1 1 1

1 2

* *

2 2 1 1

*

2 1 1 2 2 1

1 2 2 1*

2 1

/

1

/

/

1 /

R wf

wf R

R wf wf R

wf R R

R R

wf

q J P P

q J P P

q q

J P P J P P

P J J P P J J

P P J JP

J J

Pwf must be < for the well to have rate

Find Pwf at which all zone 2 rate (produced) equals zone 1 rate (injected)

IPR for Stratified Reservoir

If Pwf < Pr1, no cross flow between zones

If Pwf > or = , all zone2 flow will be injected into zone 1 (dead)

If > Pwf > Pr1, some of zone 2 rate will be injected into zone 1

No cross flow

Cross flow cases:

Example 1

A vertical was drilled west of Abqaiq Field crossing Arab-D Zone 1 (h=20 feet, K=20md) and Arab-D zone 2 (h=150 feet, K=250md). Test shows good communication between Zone 1 & 2. Would Zone 1 contribute to the flow if Pwf at sand face =2000 PSI? Arab-D Pressure = 2750, BBP=1650, Rw=0.5ft, Re=750m, Bo=1.3, Skin=+0.5, Viscosity=2 cp

0 .0 0 7 0 8

ln 0 .4 7 2 / '

o

o o e w

k hJ

B r r S

=0.000344 * K * h

J1=0.14 , J2=13.0 Q1= 105 Bll, Q2=9750

Since both reservoirs are on hydraulic communication, no cross flow Zone 1 contribution is ~ 1% of the flow below the accuracy of any flow meter. In other words, Zone 1 will not be depleted while competing with Zone2

Example 2

Another vertical was drilled north of Abqaiq Field crossing Arab-D Zone 1 (h=18 feet, K=22md) and Arab-D zone 2 (h=160 feet, K=350md). Test shows no communication between Zone 1 & 2. PRz2=2750 psi, PRz1=2350 psi Is there any cross flow if Pwf at sand face =2400 psi? or 2200 psi? BPP=1650, Rw=0.5ft, Re=750m, Bo=1.3, Skin=+0.5, Viscosity=2 cp

0 .0 0 7 0 8

ln 0 .4 7 2 / '

o

o o e w

k hJ

B r r S

=0.000344 * K * h

J1=0.13 STBD/PSI J2=19.0 STBD/PS

=2747 psi

At this Pwf Q2=57 STBD Will be all injected into Zone I. Well will be dead

Example 2

=2747 psi

At pwf = 2400 psi there will be cross flow as follow: Q2= (2750-2400)*19=6650 STBD Q1(Injec)=(2400-2350)*0.13=6 STBD Well is flowing but minor cross flow

At pwf = 2200 psi there will be no cross flow as follow: Q2= (2750-2200)*19=10450 STBD Q1=(2350-2200)*0.13=20 STBD <1% Well is flowing with no cross flow

Horizontal Wells with Reservoir Zonation

Ref (2011):

Horizontal Wells with Reservoir Zonation

Example

Zone1: K1=250 md, L1=3000 ft Zone 2: K2=100 md, L2=2500 ft

A 5500’ Horizontal well was drilled in Ghawar field with two distinct zones: rw=0.5 ft, Re=500 m, Viscosity= 2cp, Bo=1.3, h=50 ft, Skin=0.0, BPP=1800 psi Res P ~ 2800 psi

1- Neglecting the pressure drop in the wellbore, and assuming that you have pressure connectivity between zones, can you estimate the expected rate if Pwf at the heel is approximately going to be 2000 psi?

2- After drilling the well and conducting MTD test, you found that your assumption of pressure connectivity is not correct where you measured Reservoir pressure and found that Pr1= 2700 psi and Pr2= 2800 psi Is there going to be cross flow between the two zones? If yes, how to complete the well to prevent it? In this case, how much rate this well can deliver?

You can use Joshi, Furui, Butler IPR model, or Darcy for simplicity

0 .00708

ln 0 .472 / '

o

o o e w

k hJ

B r r S

Ji= 0.0186 * ki

J1=4.6, J2=1.86

q2= 0.0186 * 100 * (2800-2000) =1488 Bll

q1= 0.0186 * 250 * (2800-2000) =3720 Bll

qt= 5208 Bll

Is the assumption of zero pressure drop in the wellbore is good? Lets assume pressure drop due to friction in Z1=16 PSI, Z2=12 PSI

q1= 0.0186 * 250 * (2800-2000-16/2) =3683 Bll

q2= 0.0186 * 100 * (2800-2000-16-12/2) =1447 Bll

qt= 5130 Bll < 1.5% Is Pressure Drop is important?

Example

2000 2008 2022

Example

In case if not connected reservoirs?

Pr2=2800 Pr1=2700

In case of Pwf at heel = 2000 PSI, Pwf at mid Zone 1 = 2000 +16/2=2008 < Pr1 & < Pwf* === There will be no cross flow

Pwf*=2730 psi

Example

Another Scenario Two Separate r where

Pr2=2600, J2=1.86 Pr1=2000, J1=4.6

In case of Pwf at heel = 1900 PSI, Pwf at mid Zone 1 = 1900 +16/2=1908 < Pr1 & < Pwf* === There will be no cross flow

Pwf*=2172 psi, Q=790 Bll

Pr1=2000 and Pr2=2600

If > Pwf > Pr1, some of zone 2 rate will be injected into zone 1

Horizontal Wells with Reservoir Zonation

Ref (2011):

Horizontal with Reservoir Zonation & ICD or ICV

PDCq

2

2)(800,22Choke Eq

Multilateral Wells with/without Reservoir Zonation

- Same Reservoir with connectivity - Same Reservoir with no connectivity - Different n Reservoirs

If you have surface Rate, and down hole Pressure reading?

Multilateral with/without Reservoir Zonation & ICD or ICV

- Same Reservoir with connectivity - Same Reservoir with no connectivity - Different n Reservoirs

HM#4, Due to March 12th, 2013

Select one of these two papers and summarize the proposed Multilateral IPR model. If possible program it into XL sheet. You can also select any other Multilateral IPR model proposed in the literature