1. Pioneer Natural Resources
IMPROVING DUAL POROSITY SIMULATION OF WATERFLOOD PERFORMANCE IN THE NATURALLY FRACTURED SPRABERRY TREND AREA
By Tanvir Chowdhury
Texas A&M University

2. Spraberry Trend Area
It is a very large field in areal extent (400,000 acres)
A NFR with extensive
vertical fractures
Poor ultimate recovery
Glasscock Co
Reagan Co
Upton Co
Midland Co
Martin Co
Borden Co
Pioneer Natural Resources’ Spraberry Unit Position
Spraberry Trend Area
Investigated the waterflood performance of an old (Humble Pilot) and a new (O’Daniel Pilot) Waterflood.
Find methods to extend and apply the results found from the Humble and O’Daniel Pilot simulations to all over the Spraberry Trend area
Largest field in the World
Its in the Midland Basin of West Texas
Spraberry Is extensively Naturally Fractured
Midkiff is one of the Units in spraberry where Humble Oil Company started a Waterflooding Pilot.

3. Presentation Outline Step 1 Step 2
Applied
Simulation of tracer response from the present waterflood pilot
Simulation of an old waterflood pilot (Humble Pilot)
Permeability anisotropy and fracture orientation
Obtained
Previous Studies
PVT Study
Log Analysis
Imbibition Study(Pc & Kr)
Pressure Transient Analysis
Production Data Analysis
Core Analysis
Outcrop Study
Step 3
Field Simulation involving multiple wells
Confirmed

4. Simulation of The Humble Pilot
Step 1
Simulation of The Humble Pilot

5. Assumptions For Simulation
Only two wells were included in the basic model, one is injector (SHB-10) and the other is producer (SHB-8) as shown in Humble Pilot map.
The production well was located in the same line with injection well (in the on-trend direction, along the primary fracture orientation).
The response of oil production rate in the SHB-8 well was only affected by water injection from the SHB-10 well. 1
MAGNOLIA “A” 3
HUMBLE “B” 10 3 2
HUMBLE “B” 4 9 5
SHACKELFORD 8
UNION 11 13 2 15 15 4
SHACKELFORD 9
HUTT 16
HUMBLE “B” 12 16 8 4 10 4 3 1 6 7 2 8 17 2 3 1
SHACKELFORD 3 1
HUMBLE “B” 2 4 1 22
SHACKELFORD 1 2 3 4
HUMBLE 1 2 21
TIPPET 2
TIPPET 20 6
TIPPET 3
TIPPET

6. Has 3 layers
2 thin pay zones and 1 thick non pay zone that is shale.
Pay zones are not Interconnected
The first layer has 1 fracture trend
the bottom layer has 2 fracture orientation
The average fracture spacing was obtained from the outcrop study ……...

7. Reservoir Properties Mention grid Dimension No. of Wells Dual porosity
Two different properties for matrix and fractures

8. Fracture
Matrix
Vugs
Grid System
Matrix
Fracture

9. Comparison Between Observed and Simulated Results
Water cut vs. time
BHP vs. time

10. Simulation of The Tracer Test Conducted in The O’Daniel Pilot
Step 2
Simulation of The Tracer Test Conducted in The O’Daniel Pilot

11. N Production Well Production Well Monitored During Tracer Test1
G-1
D-1
C-2
C-1
E-1 2 30 3 24 13
Boone A-1
D-1
F-1
Boone 19
A-1 32 6
D-1
Brunson 31 26 1 12 N 34 36 8W
O'Daniel
B-1 47
A-5 1
C-1
O'Daniel 33 46 28 42 40
Boone E-1 50 25
A-6
Production Well
Production Well Monitored During Tracer Test
Water Injector
CO2 Injector
Logging Observation Well 49 44 39 45 41 38 29
O‘Brian 43
A-7 37
A-3 48 14 35
O'Daniel
A-1
This is the CO2 pilot area of the ET O’Daniel Lease of the Spraberry Trend
The Pilot consists of 3 central producers and 6 ring fence water injectors
Tracer was injected into the injectors beginning from Aug 2000.
The response from the far away wells means that the fracture permeability is very high
Strong NE-SW response conforms with the fracture orientation obtained during the Core Analysis (Rose Diagram) 13 9 10 63
O'Daniel 5 9 7 12
B-1 8 7
O‘Brian
D-1 12
Powell
Floyd
C-1

12. N Production Well Production Well Monitored During Tracer Test
Water Injector
CO2 Injector
Logging Observation Well N
C-1 1
G-1
D-1
C-2
C-1
E-1 2 30 3 24 13
Boone A-1
D-1
F-1
A-1
Boone 19 32 6
D-1
Brunson 1 31 26 12 34 36 8W
O'Daniel
B-1
A-5 1
C-1 47
O'Daniel 33 46 28 42 40
Boone E-1 50 25
A-6 49 44 45 39 41 29
O‘Brian 38 43
A-7 37
A-3 14 48 35
O'Daniel
These are the tracer paths where the highest concentration of tracer was observed > PPT
Among these 4 tracer responses we analyzed two of them
A-1 13 10 9 63
O'Daniel 5 9 7 12
B-1 8 7
O‘Brian
D-1 12
Powell
Floyd
C-1

13. b) Shape of The Actual Response From WIW#47 to O’Daniel D-1
Concentration
Concentration
Time
Time
This is a typical tracer response that is obtained from any commercial simulator
Only the first peak was matched with the simulation result.
The second peak is due to another set of fracture or due to another pay layer contributing the producer.
a) Typical Response
b) Shape of The Actual Response From WIW#47 to O’Daniel D-1

14. Model Dual porosity with tracer option using Eclipse47
O'Daniel
Brunson
D-1
Model
Dual porosity with tracer option using Eclipse
Grid block is 100 x 100
Number of wells 2, one injector (E.T. O’Daniel #47) and one producer (Brunson “D” 1).
Rock and fluid properties from Humble Simulation model.
Tracer injection concentration is ppm for hrs.
O'Daniel
Brunson
D-1 47 25 29 37 46 45 38 39 40 48 14
A-1 35 33 32 12 8W 34 24 31 36 13 30
C-1 28
Production Well
Water Injector

15. History Match Result (W#47-Br.D-1):
Kx/Ky= 84/15000
Orientation 43 Deg.

16. Fracture Orientation Obtained From The Tracer Test
O'Daniel
O‘Brian
Brunson
Boone
Powell
Floyd 35 33
B-1
D-1
C-1 5 7 12 9 13 10 63 8
A-1 1
A-5
Boone E-1
A-6
A-3
A-7 32 8W 34 6 24 31 36 26 19 30
G-1
C-2
E-1
Boone A-1
F-1 3 2 47 25 29 37 46 28 45 38 39 40 48 14 41 43 49 50 44 42

17. Simulation of O’Daniel Unit and Surrounding Wells
Step 3
Simulation of O’Daniel Unit and Surrounding Wells

18. O’Daniel Unit Simulation
Model
Dual porosity with tracer option using CMG simulator
Grid block is 130 x 130 with 3 x 2 layers
The 8,383-acre area of the model contains 15 injectors and 44 producers
Rock and fluid properties were obtained from The Humble Simulation model.

19. Structural Map For The O’Daniel Unit Simulation Model
Building The Model
The Structural map was scanned and digitized.
The digitized map is then uploaded to the CMG Gridbuilder to build the geological model
Structural Map For The O’Daniel Unit Simulation Model

20. Results Obtained From Previous Studies
There are 3 layers in the model.
Only the first and the third layers contribute to the production and the middle layer is a non-producing shale layer.
The Simulation Model
Results Obtained From Previous Studies

21. Production Well Water Injector O'Daniel O‘Brian Brunson Boone Powell
Floyd 35 33
B-1
A-1
Boone E-1
A-6
A-3
A-7 32 12 8W 34 24 31 36 26 19 13
G-1
C-2
E-1
Boone A-1
D-1
F-1
C-1
47W 29
37W
46W 28
45W 38 39 40
48W
14W
10W 5W 16 21 2 7W 22
20W 1 27 23 3 4W 9W
11W
McClintic
E-42
E-32 8
Brown
E.T. O’Daniel Unit
25W 30

22. Production Well Water Injector Brown G-1 E-32 E-42 C-2 C-1 10W E-1
O'Daniel
O‘Brian
Brunson
Boone
Powell
Floyd 35 33
B-1
A-1
Boone E-1
A-6
A-3
A-7 32 12 8W 34 24 31 36 26
D-1 19 13 30
G-1
C-2
E-1
Boone A-1
F-1
C-1
47W
25W 29
37W
46W 28
45W 39 40
48W
14W
10W 5W 16 21 2 7W 22
20W 1 27 23 3 4W 9W
11W
McClintic
E-42
E-32 8
Brown
E.T. O’Daniel Unit 38

23. The Reservoir Model With Fractures

24. Fracture Water Saturation

25. Summary (Humble Pilot)
The fracture permeability values in the on-trend and off-trend directions of and 100 md, respectively, indicate that reservoir permeability is highly anisotropic.

26. Summary (Tracer Test)
The results obtained from this study support the previous analyses as follows:
The on-trend and off-trend permeability in the O’Daniel Unit are close to the value obtained from the Humble Pilot simulation.
The orientation of the fracture trend as determined by the tracer test agrees with the orientation obtained from historical production data, interference testing and horizontal core analysis.

27. Summary (O’Daniel Field Simulation)
For field simulation history matching, it is necessary to introduce existing fractures where there is not enough water production from off-set injectors.
It is possible to match most of the wells by using the permeability anisotropy (Kx/Ky) and fracture orientation obtained from the tracer simulation in the O’Daniel field model
To investigate areas of Spraberry where little or no water injection has occurred .
The results of this work will provide a method to assess the economic feasibility of large-scale water injection in the remainder of the field.

28. Conclusions
The methods described here can be used to investigate areas of Spraberry where little or no water injection has occurred .
The results of this work will provide a method to assess the economic feasibility of large-scale water injection in the remainder of the field.
To investigate areas of Spraberry where little or no water injection has occurred .