Water Flooding

1
Water Flooding

• Principles Simulation

2
team

1. Ahmed Magdy Abdel-Kereem
2. Farid Abdel-Salam Al-shazly
3. Mohammed Ahmed Shawky
4. Mohammed Borhan Bakeer

3
Part Iwater flooding principles
4
Reservoir drive mechanisms
5
1. Drive Mechanisms
6
1. Drive Mechanisms
7
1. Drive Mechanisms

• C. Gravity

8
1. Drive Mechanisms

• Water Drive
• Base water

9
1. Drive Mechanisms

• D. Water Drive
• 2. Edge water

10
(No Transcript)
11
(No Transcript)
12
Types of recovery
13
2. Types of Recovery

• Primary oil recovery
• Refers to the recovery come from natural flow of
  the well or using artificial lift methods.

14
2. Types of Recovery

• B. Secondary oil recovery pressure
  maintainance
• The additional recovery that results from the
  conventional methods of water injection and
  immiscible gas injection.

15
2. Types of Recovery

• C. Tertiary oil recovery
• Refers to using principles of EOR like using
  surfactants, thermal, acoustic

16

• Waterflooding
• Is the process of injection compatible water
  under pressure into the reservoir in order to
  enhance or maintain the reservoir driving energy,
  consequently, increasing the reservoir recovery.

17
Why Waterflooding?

• Most widely used fluid injection process
• Its a mature technology
• Water availability is generally good
• Proven method to increase oil recovery

18
(No Transcript)
19
Important Waterflood Factors
20

• Reservoir Geometry
• Lithology, Porosity, Permeability
• Reservoir Depth
• Continuity of Rock Properties
• Fluid Saturations Distributions
• Fluid Properties
• Relative Permeability
• Other Considerations
• Primary Drive Mechanism(s)

21
Reservoir Geometry

• Areal geometry influences well facilities
  locations
• If offshore, number and location of platform(s)
• may provide insights on aquifer location
  strength

22
Lithology, Porosity, Permeability

• Rock types
• Clay type and content
• Mobile clays
• Swelling clays (e.G., Montmorillonite)
• Porosity
• Effective vs. Total porosity
• Dual porosity systems

23
Lithology, Porosity, Permeability

• Permeability
• Speed at which the flood progresses
• Well spacing
• The pressure history may influence the
  porosity/permeability

24
Reservoir Depth

• Drilling costs a function of depth
• dual porosity systems
• Temperature gradient
• oil viscosity vs. temperature
• If primary operations were extensive
• Fracturing (max. injection pressure vs. depth)
• Fracture type (vertical vs. horizontal)

25
Continuity of Rock Properties

• Hydraulic connectivity is critical
• Variance in permeability
• Spatial location of the different permeable
  layers
• Faults fractures
• Location, orientation, length, conductivity
• Effective permeability on an inter-well basis
• Cross-bedding

26
Continuity of Rock Properties
27
Fluid Saturations Distributions

• High Sw (risky)
• lower moveable oil target
• Free gas saturation
• higher free gas saturation, longer wait for flood
  response
• Uneven fluid distributions
• depleted reservoir often have gas at top
• Primary or secondary gas caps complicate
  waterflood
• Bottom water drive may cause problems

28
Fluid Properties

• Maintain oil viscosity at a minimum
• improved oil mobility, mobility ratio
• improved areal sweep flood efficiency
• less free gas, less time waiting for flood
  response
• High oil formation volume factor (Bo)
• GORs GLRs

29
Relative Permeability

• Shape of relative permeability curves impacts oil
  bank formation
• End point relative permeability to water may
  impact injectivity
• Relative permeability from depletion doesnt
  apply to waterflooding

30
Other Considerations

• Pressure
• keep average reservoir pressure high for improved
  well hydraulics equipment costs are higher for
  increasing pressures
• Waterfloods should always be evaluated while
  considering the project life-cycle with other EOR
  methods in mind

31
Waterflood Phases

• Fill Up
• pressure up
• GOR down
• oil decline rate slows
• averages 5 to 11 of project life
• Inclining Production
• averages 6 to 30 of project life
• Declining Production
• most of the project life is during this period

32
When to Waterflood?

• Define your objectives
• maximum oil recovery
• highest investment efficiency
• maximize net present value
• minimize risk
• Perform economics for various start up times,
  considering
• revenue stream (oil gas)
• injection requirements
• cost of fluid handling treatment
• cost of facilities

33
Choices For Waterflooding Pressures

• Operate at initial pressure (or above) minimize
  compaction
• producing well PIs
• Operate at or above bubble point pressure (PBP)
• minimize remaining stock-tank volumes left in
  reservoir
• oil viscosity minimized
• Operate below PBP (free gas saturation to form)
• oil trapped in waterflooded portion of reservoir
  increases
• residual oil saturation to water drops
• longer fill up times delayed oil production
  response

34
(No Transcript)
35
(No Transcript)
36
(No Transcript)
37

• Vertical sweep efficiency

38
(No Transcript)
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
Part IIwater flooding simulation
43
About the model used

• Simulator Eclipse 100
• Flooding Pattern Five-spot
• Case QFIVE.DAT

44
(No Transcript)
45
(No Transcript)
46
(No Transcript)
47
(No Transcript)
48
(No Transcript)
49
Effect of changing oil viscosity on FOPT
FOPT STB
TIME DAYS
50
effect of changing oil viscosity on FOPR
FOPR STB
51
Effect of changing oil viscosity on FWCT
FWCT STB
52
Effect of changing oil viscosity of BPR
BPR STB
53
Effect of water injection rate on FOPT
FOPT STB
54
Effect of water injection rate on FOPR
FOPR STB
TIME DAYS
55
Effect of water injection rate on FWCT
FWCT STB
TIME DAYS
56
Effect of water injection rate on BPR
BPR STB
TIME DAYS
57
Selecting optimum injection rate
FOPT STB
Injection rate BPD
58
Effect of Changing water viscosity on BPR
59
Effect of Changing water viscosity on FWC
60
Effect of Changing water viscosity on FOPT
61
Effect of Changing water viscosity on FORP
62
Effect of changing grid size on BPR
63
Effect of changing grid size on FWCT
64
Effect of changing grid size on FOPT
65
Effect of changing grid size on FOPR