PGE385MSpring 2002 Semester
Lecture Presentation, January 17
INTEGRATED FORMATION EVALUATION
Carlos Torres-Verdín, Ph.D.Assistant Professor
The University of Texas at Austin
Formation Evaluation
Formation Evaluation Flowchart
Density: Influence of Porosity and Saturation
Equations and Tools
Linear Equations and Volumetric Models
Linear Equations and Volumetric Models
Formation Evaluation: Basic Data
250 cm 200 150 100 50 0 cm
80 cm
80 cm
40 cm30 cm 20 cm
60 cm
5 cm 2 cm 0 cm
INDUCTION LOG
LATEROLOG
NEUTRONGAMMA RAY
DENSITY
SONICMICRO RESISTIVITY
MICROLOGDIPMETER
DEPTH OF INVESTIGATION
RES
OLU
TIO
NRESISTIVITY
RADIOACTIVITY
RESISTIVITY
ACOUSTIC
Logging Tools
MUD-FILTRATEINVASION
EXPERIMENT
Mud-Filtrate Invasion Experiment
Open-Hole Logging Environment
Dynamic Mud Filtrate Invasion and Mud Cake Buildup
Source: Oilfield Review, Schlumberger
NOMENCLATURE
Porosity
GENERALIZED COMPARISON
DensityMeasurements
in the Borehole
Typical Borehole Density Tool Configuration
COMPENSATED NEUTRON LOG
A SIMPLE EXPERIMENT
NEUTRON POROSITY TRANSFORMS
NEUTRON PHENOMENA AS A FUNCTION OF ENERGY
POROSITY AND LITHOLOGY
PULSED NEUTRON THEORY
PorosityLogs:
Neutron,Density,
NMR
Laminated Clean Gas Sand
SONIC LOGGING: BASIC PRINCIPLES
Single Transmitter-Dual Receiver Tool
SONIC LOGGING
Static and Dynamic Deformation
Monopole in a Fast Formation
SONIC POROSITY: Intuitive Model
Sonic Porosity: Theory and Measurements
Acoustic Log: Core Calibration
LWD/Wireline Neutron-Density Comparison
Effects of Drilling Muds on Log Responses
Shale, Silt, and Clay
Low-Resistivity Sand
Pore-Filling Kaolinite
Pore-Lining Chlorite
Chlorite
Pore-Bridging Illite
Vshale DETERMINATION
Electrical Response of Rock Formations
POROSITY
• TOTAL WATER SATURATION?
• BOUND-FREE (MOVABLE) WATER?
• IRREDUCIBLE WATER SATURATION (i.e. clay-bound water and capillary-bound water)?
WATER SATURATION
• TOTAL POROSITY?
• EFFECTIVE POROSITY?
ARCHIE’S “Clean Sand” EquationEffective DC Resistivity Response
RESISTIVITY: Influence of Water Saturation
Water-Wet Hydrocarbon-Bearing Rock Formation
Wilcox SandOklahoma City
1 cm
Close-Up
Clay
ELECTRICAL PROPERTIES OF SHALY SANDS
Shale-Free Electrical Model
•• Archie (1942)Laminated Shale Electrical Model
•• Poupon-Leveaux (Indonesian))
“Double-Layer” Dispersed Clay Electrical Models
•• Waxman-Smits
•• Dual-WaterMixed Dispersed-Clay / Laminar-Shale Electrical Model
•• Patchett-Herrick
Several Water Saturation Models
Water Adsorption by Clays[Cation-Exchange-Capacity (CEC) Mechanism]
Shale Distribution
MULTIPLE SHALE VOLUME MODELS
WAXMAN-SMITS “Dispersed Clay” Equation
Effective DC Resistivity Response
POUPON “Laminar Sand-Shale” Equation
Effective DC Resistivity Response
PATCHETT-HERRICK (Poupon + Waxman-Smits) EquationEffective DC Resistivity Response
GR & Caliper
Permeability & Resistivity Archie T2
SpectraWaxman
SmitsDual Water
Poupon -Leveaux
Patchett -Herrick
Formation Volumetrics
MULTIPLE WATER SATURATION INTERPRETATIONS
Mineralogy Determination
Imaging Thin Beds
Formation Testing
Pressure-Drawdown Analysis
Fluid Gradients
Fluid Contacts and Density
Permeability
Fractured Reservoirs
Photograph courtesy of Prof. Jon Olson
WHEN DOES THEORY BREAK DOWN?
Example of Microfracturing
SUMMARY
Acknowledgements
• Baker Atlas
• Schlumberger
• Halliburton