Phân tích và dự báo

PRODUCTION ANALYSIS
AND FORECAST

Dr. Mai Cao Lan, HCMUT
August, 2017


Outline
 An Overview of Petroleum Production System
(PPS) and the Nodal Analysis Method for PPS
 Analysis of Reservoir Performance
 Analysis of Wellbore Performance
 Analysis of Choke & Flowline Performance
 Analysis of Petroleum Production System

8/21/2017

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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Text Books
 Michael J. Economides et al. (1994). Petroleum
Production Systems. Petroleum Engineering
Series. Prentice Hall.
 H. Beggs (2003). Production Optimization using
Nodal Analysis. OCGI & Petroskills Publications.
 Mukherjee & Brill (1999). Multiphase Flow in
Wells. Society of Petroleum Engineers.
8/21/2017

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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OVERVIEW OF
PETROLEUM PRODUCTION
SYSTEM & NODAL ANALYSIS
METHOD
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Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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Petroleum Production System
Gas Sales

Flowing Wellhead
Pressure

Horizontal Flowline

Separator
Stock Tank

Vertical or Inclined
Tubing

Intake

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Flow Through
Porus Media
P, K, IPR

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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System Analysis for Petroleum
Production Systems
• Analyze the performance of the system taking into
account ALL of its components
• Figure out potential problems associated with the
production system
• Analyze the behavior of the system in response to
any changes of a component
8/21/2017

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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NODAL Analysis (NA) Method

• NODAL Analysis belongs to System Analysis
Methods applied in Petro Eng.
• The method allows production engineers to
analyze the performance of a petroleum
production system
• The method help production engineers to
select optimal system parameters
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Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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Fundamentals of the NA Method
• Always consider a component in the relationships
with the others
• Pressure and Pressure Losses across different
components of the system are of primary
interests
• The performance of a system can be analyzed via
one or more NODEs
8/21/2017

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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Possible Pressure Losses

Gas Sales

P8

Pwh

P6
Psep

P5

PDSV

Separator
Stock Tank

P4
PUSV

P1 = (Pr - Pwfs)
P2 = (Pwfs - Pwf)
P3 = (P UR - P DR)
P4 = (P USV - P DSV)
P5 = (Pwh - P DSC)
P6 = (P DSC - Psep)
P7 = (Pwf - Pwh)
P8 = (Pwh - Psep)

P7

PDR
P3

= Loss in Porus Medium
= Loss across Completion
= Loss across Restriction
= Loss across Safety Valve
= Loss across Surface Choke
= Loss in Flowline
= Total Loss in Tubing
= Total Loss in Flowline

PUR

Pwf
P2

Pwfs

Pr
P1

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Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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Locations of Various Nodes

1A

2

3

1

4

1B

5

6

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Node

Location

1
2
3
4
5
6

7
8
1A
1B

Separator
Surface Choke
Wellhead
Safety Valve
Restriction
Pwf
Pwfs
Pr
Gas Sales
Stock Tank

Remarks
Functional
Functional
Functional

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Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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Typical Nodes for System Analysis

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Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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The Underlying Idea of NA

Downstream

Node of Interest

Upstream

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Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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The Underlying Idea (cont’d)
Upstream
pr  pupstream  pnode  f (q )
Downstream
psep  pdownstream  pnode  g (q )
At any point in time t during the production process,
the average reservoir pressure and the separator
pressure are given as constants.

8/21/2017

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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The Two Essential Principles
• There is ONLY ONE value of pressure at a
node (physical point);
• The flow rate coming into a node is equal to
the flow rate going out of that node (mass
conservation).

8/21/2017

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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Graphical Representation of NA
p

Outflow Curve
(Downstream)

Inflow Curve
(Upstream)

pop

Operating Point

qop

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q

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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NA Applications – System Analysis
p

Steep Outflow Curve (Bottle
Neck)

Expected Outflow
Curve

q

8/21/2017

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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NA Applications – Sensitivity Analysis
p

Outflow Curve with
tubing diameter
d3
Outflow Curve with
tubing diameter d1

Outflow Curve with
tubing diameter
d2>d1

q3

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q1

q2

q

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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NA Application – Production Optimization
q
q4
q5
q2
q1

q3

Using a TRIAL-AND-ERROR approach, the
optimal tubing diameter can be found
where the flow rate reaches the
maximum value

d3

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d1

d2

d4

d5

d

Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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ANALYSIS OF
RESERVOIR
PERFORMANCE
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Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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Reservoir Capability
• Darcy’s Law
– Liquid flow in Laminar Flow through a permeable
medium is described by Darcy’s Law

7.08 X 10 k h  p  pwf
3

Q

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

  re 


o Bo  ln    0.75  s 
  rw 


Dr. Mai Cao Lân, Faculty of Geology & Petroleum Engineering, HCMUT, Vietnam

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