Dynamic Flow Analysis (DFA)

Section 1 - Introduction

1.C

Dynamic Flow Analysis

DFA

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Dynamic Flow Analysis (DFA)

Temperature
Analysis
Well Test
Interpretation
Formation Tests
Pressure Transient Interpretation
Analysis

Production
Dynamic Flow Analysis
Analysis

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 Dynamic Flow Analysis (DFA)
Section 1 - Introduction

1.D

Pressure Transient Analysis

PTA

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Typical well test set-up

Surface rates
Surface samples

WHP
Acquisition
Interpretation

BHP & BHT

Downhole rates
Bottom hole samples

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 Pressure Transient Analysis

rates

pressures
analysis
PVT

other infos

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1950’s – Specialized plots

• Quantify kh & skin in Infinite Acting Radial Flow (IARF)

• Other specialized plots for other flow regimes

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 1970’s – Type-curve matching

Manual type curve matching Homogeneous loglog type-curve

• Low diagnostic capability

• Complemented semilog plot

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1980’s – Bourdet derivative

Superposition plot Derivative plot

Bourdet derivative type curve

• Slope of the semilog plot plotted on the loglog plot

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 1990-2000’s – PC based PTA

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1990’s – Advanced analytical models

Fractured horizontal well 2 K radial composite

Conductive fault

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 1990-2000’s – Numerical models

Saphir analysis window

2-D Map, reservoir geometry

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2005-2006 – Deconvolution

history match

Deconvolution
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 Dynamic Flow Analysis (DFA)
Section 1 - Introduction

1.E

Production Analysis
PA

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1920’s – Arnold & Cutler

Arnold (1919) Cutler (1924)

• Empirical relations
• Purely developed for economics and tax purposes

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 1940’s – Arps

• Rates only
• Constant pressure production
• Exponential, hyperbolic and harmonic formulations
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1970’s – Fetkovich type-curve

• Rates only
• Constant pressure production
• Simultaneous match of Rates + Cumulative
• Pi and Pwf= constant, assumed known
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 1980’s – Blasingame plot

• Rates + Pressures
• Superposition + Material balance
• Productivity index (Normalized rate by pressure)
• Bourdet derivative on loglog plot
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1980’s – Loglog plot

• Rates + Pressures
• Superposition + material balance
• Loglog plot of normalized pressure by rate
• Bourdet derivative
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 2000’s – PC based PA

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Dynamic Flow Analysis (DFA)

Section 1 - Introduction

1.F

PTA vs. PA

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 PTA vs. PA

PTA PA

Same equations and superposition

Theory
Same analytical and numerical models

Time range Hours, Days Weeks, Months, Years

Periods of interest Mostly shut-ins Producing phases

Well tests Production
Data sources Formation tests Surface pressure
Permanent gauges (PDG) Permanent gauges

Reservoir areas Investigation volume Well or group drainage area

Traditional plots MDH, Horner Arps

Traditional type-curves McKinley, Gringarten Fetkovich

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PTA vs. PA

PTA PA

Loglog Loglog + Blasingame

Modern plots
with Bourdet derivative with Bourdet derivative

Main flow regime Infinite Acting Radial Flow Pseudo-Steady State (PSS)

Main results
kh & skin drainage area & shape factor

Diagnostic capability High to very high Average to low

Long term
Average to low High to very high
representatively

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 Dynamic Flow Analysis (DFA)
Section 1 - Introduction

1.G

Usage and Interpretation of

Permanent Downhole Gauge data
PDG

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PDG data: Issues

• Rates + Pressure = Analysis

• High frequency + short duration=PTA
• ‘Free’ well tests
• Low frequency + long duration=PA
• History match

• High frequency* Long duration = Masses of points

• 3.106 to 300.106 points / gauge
• Dual frequency, ‘smart’ filter (wavelets)

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 PDG data: Wavelet filtering

92 pts

16,839 pts 3 – End result

2 – Post-filtration

1 - Setting wavelet

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PDG data: Usage

Raw Wavelet Filtered

PTA PA
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 Dynamic Flow Analysis (DFA)
Section 1 - Introduction

1.H

Other candidates for

Dynamic Flow Analysis

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Formation Testers

Information acquired:
• Static and transient pressures
• Reservoir gradients
• Fluid contacts
• Samples (PVT)

Effective results using standard PTA:

• Horizontal permeability
• Vertical permeability
• Spherical permeability
• Skin damage

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 Formation Testers

Formation tester loglog plot Formation tester history plot

Produced volume: 1000 cc

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Temperature Sensors

• DTS = Distributed Temperature Sensing

• ATS = Array Temperature Sensing
• Distributed fiber optic sensor cables
• Real time T + P profiles
• High P, high T
• Downhole reservoir monitoring
• Early detection of water and/or gas breakthrough
• Individual layer rates
• Monitoring of gas lift systems
• Detection of well problems

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 Temperature Diffusion

• Work in progress (2006) – To be released in Rubis (2007)

• Probably no TTA (Temperature Transient Analysis)
• More likely a History matching tool
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