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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
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
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
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