(modified from Blatt, 1982)
DUNHAM’S CLASSIFICATION - CARBONATES
Carbonate rocks can be classified according to the texture and grain size.
From Schlumberger Oilfield Glossary
Modified from Tiab and Donaldson, 1996, p. 1
RESERVOIR PETROPHYSICS PETE 311
COURSE DESCRIPTION
Systematic theoretical and laboratory study of physical properties of petroleum reservoir rocks
DEFINITIONS - SEDIMENTARY ROCK
Sedimentary Rock
Rock Formed from the Weathered Products of Pre-Existing Rocks and Transported by Water, Wind, and Glaciers Clastic Sedimentary Rocks (Such as Shale, Siltstone, and Sandstone) Consist of Broken Fragments of Pre-Existing Rock (cf. Detrital) Carbonate Sedimentary Rocks (and Evaporites) May Form by Chemical Precipitation or Organic Activity
Consist Primarily of Carbonate Minerals (i.e. Minerals With a CO3 Anion Group)
- Predominately Calcite (Limestone) - Predominately Dolomite (Dolomite or Dolostone) Classified by Grain Size and Texture -2
(These are minimum skills to be achieved/demonstrated)
PETROPHYSICS
• Why do we study petrophysics?
Cross Section Of A Petroleum System
(Foreland Basin Example)
Millimeters
4,096
Micrometers
256 64 4 2 1 0.5 0.25 0.125 0.062 0.031 0.016 0.008 0.004
Commonly, phi-sizes are used for sediment analysis
500 250 125 62 31 16 8 4
Grain-Size Classification for Clastic Sediments
Name
Boulder Cobble Pebble Granule Very Coarse Sand Coarse Sand Medium Sand Fine Sand Very Fine Sand Coarse Silt Medium Silt Fine Silt Very Fine Silt Clay
CLASTIC AND CARBONATE ROCKS
Clastic Rocks
Consist Primarily of Silicate Minerals Are Classified on the Basis of:
- Grain Size - Mineral Composition
Carbonate Rocks
2.
3.
RESERVOIR PETROPHYSICS
Course Objectives
4. Explain boundary tension and wettability and their effect on capillary pressure, describe methods of determining values of capillary pressure, and convert laboratory capillary pressure values to reservoir conditions; Describe methods of determining fluid saturations in reservoir rock and show relationship between fluid saturation and capillary pressure; Define resistivity, electrical formation resistivity factor, resistivity index, saturation exponent, and cementation factor and show their relationship and uses; discuss laboratory measurement of electrical properties of reservoir rocks; and demonstrate the calculations necessary in analyzing laboratory measurements;
Geographic Extent of Petroleum System Extent of Play Extent of Prospect/Field O
Stratigraphic Extent of Petroleum System
O
O
Petroleum Reservoir (O) Fold-and-Thrust Belt (arrows indicate relative fault motion)
(modified from Magoon and Dow, 1994)
Essential Elements of Petroleum System
Seal Rock Reservoir Rock Source Rock Underburden Rock Basement Rock Top Oil Window Top Gas Window
Course Objectives
By the last day of class, the student should be able to:
1. Define porosity; discuss the factors which affect porosity and describe the methods of determining values of porosity; Define the coefficient of isothermal compressibility of reservoir rock and describe methods for determining values of formation compressibility; Reproduce the Darcy equation in differential form, explain its meaning, integrate the equation for typical reservoir systems, discuss and calculate the effect of fractures and channels, and describe methods for determining values of absolute permeability;
Sedimentary Basin Fill
Overburden Rock
PETROLEUM SYSTEM
From Schlumberger Oilfield Glossary
Timing of formation of the major elements of a petroleum system, Maracaibo basin, Venezuela.
GENERATION, MIGRATION, AND TRAPPING OF HYDROCARBONS
Seal
Fault (impermeable)
RESERVOIR PETROPHYSICS PETE 311
PETROPHYSICS
Petrophysics is the study of rock properties and rock interactions with fluids (gases, liquid hydrocarbons, and aqueous solutions).
• Lithology • Porosity • Compressibility • Permeability • Fluid saturations • Capillary characteristics • Rock stress • Fluid-rock interaction
RESERVOIR PETROPHYSICS
SEDIMENTARY ROCK TYPES
Relative Abundances
Sandstone and conglomerate (clastic) ~11%
Limestone and Dolomite (carbonate) ~14%
Mudstone (Siltstone and shale; clastic) ~75%
5.
6.
RESERVOIR PETROPHYSICS
Course Objectives