reservoir petrophysics pete 311
DESCRIPTION
RESERVOIR PETROPHYSICS PETE 311. PETROPHYSICS. Petrophysics is the study of rock properties and rock interactions with fluids (gases, liquid hydrocarbons, and aqueous solutions). Modified from Tiab and Donaldson, 1996, p. 1. RESERVOIR PETROPHYSICS PETE 311 COURSE DESCRIPTION. - PowerPoint PPT PresentationTRANSCRIPT
RESERVOIR PETROPHYSICS
PETE 311
PETROPHYSICS
Petrophysics is the study of rock properties and rock interactions with fluids (gases, liquid hydrocarbons, and aqueous solutions).
Modified from Tiab and Donaldson, 1996, p. 1
RESERVOIR PETROPHYSICSPETE 311
COURSE DESCRIPTION
Systematic theoretical and laboratory study of physical properties of petroleum reservoir rocks
• Lithology• Porosity• Compressibility• Permeability • Fluid saturations• Capillary characteristics• Rock stress• Fluid-rock interaction
RESERVOIR PETROPHYSICSCourse Objectives
By the last day of class, the student should be able to:
1. Define porosity; discuss the factors which effect porosity and describe the methods of determining values of porosity;
2. Define the coefficient of isothermal compressibility of reservoir rock and describe methods for determining values of formation compressibility;
3. 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;
RESERVOIR PETROPHYSICSCourse 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;
5. Describe methods of determining fluid saturations in reservoir rock and show relationship between fluid saturation and capillary pressure;
6. 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;
RESERVOIR PETROPHYSICSCourse Objectives
7. Define effective permeability, relative permeability, permeability ratio; reproduce typical relative permeability curves and show effect of saturation history on relative permeability; illustrate the measurement of relative permeability; and demonstrate some uses of relative permeability data.
8. Describe three-phase flow in reservoir rock and explain methods of displaying three-phase effective permeabilities.
9. Demonstrate the techniques of averaging porosity, permeability, and reservoir pressure data.
10. Demonstrate capability to perform calculations relating to all concepts above.
(These are minimum skills to be achieved/demonstrated)
PETROPHYSICS
• Why do we study petrophysics?
Cross Section Of A Petroleum System(Foreland Basin Example)
Overburden Rock
Seal Rock
Reservoir Rock
Source Rock
Underburden Rock
Basement Rock
Top Oil Window
Top Gas Window
Geographic Extent of Petroleum System
Petroleum Reservoir (O)
Fold-and-Thrust Belt(arrows indicate relative fault motion)
EssentialElements
ofPetroleum
System
(modified from Magoon and Dow, 1994)
O O
Sed
imen
tary
Bas
in F
ill
O
Stratigraphic Extent of
PetroleumSystem
Pod of ActiveSource Rock
Extent of Prospect/FieldExtent of Play
Timing of formation of the major elements of a petroleum system, Maracaibo basin, Venezuela.
PETROLEUM SYSTEM
From Schlumberger Oilfield Glossary
DEFINITIONS - SEDIMENTARY ROCK
Sedimentary Rock
Clastic Sedimentary Rocks (Such as Shale, Siltstone, and Sandstone)Consist of Broken Fragments of Pre-Existing Rock (cf. Detrital)
Carbonate Sedimentary Rocks (andEvaporites) May Form by ChemicalPrecipitation or Organic Activity
Rock Formed from the WeatheredProducts of Pre-Existing Rocks andTransported by Water, Wind, and Glaciers
CLASTIC AND CARBONATE ROCKS
Clastic Rocks
Consist Primarily of Silicate Minerals
Are Classified on the Basis of:
- Grain Size - Mineral Composition
Carbonate RocksConsist Primarily of Carbonate Minerals
(i.e. Minerals With a CO Anion Group)
- Predominately Calcite (Limestone) - Predominately Dolomite (Dolomite
or Dolostone)
3-2
Classified by Grain Size and Texture
Relative Abundances
Mudstone(Siltstoneand shale;
clastic)~75%
Sandstoneand conglomerate
(clastic)~11%
Limestone andDolomite
(carbonate) ~14%
SEDIMENTARY ROCK TYPES
Grain-Size Classification for Clastic Sediments
Name Millimeters Micrometers
BoulderCobblePebbleGranuleVery Coarse SandCoarse SandMedium SandFine SandVery Fine SandCoarse SiltMedium SiltFine SiltVery Fine SiltClay
4,096256644210.50.250.1250.0620.0310.0160.0080.004
500250125
623116
84
(modified from Blatt, 1982)
Commonly, phi-sizes are used for sediment analysis
Carbonate rocks can be classified according to the texture and grain size.
DUNHAM’S CLASSIFICATION - CARBONATES
From Schlumberger Oilfield Glossary
SealReservoir
rock
Seal
Migration route
Oil/watercontact (OWC)
Hydrocarbonaccumulation
in thereservoir rock
Top of maturity
Source rock
Fault(impermeable)
GENERATION, MIGRATION, AND TRAPPING OF HYDROCARBONS
Seal
DESCRIBING A RESERVOIRStructural Characterization
This structural trap is formed by an anticline and a normal fault. From Schlumberger Oilfield Glossary
STRUCTURAL HYDROCARBON TRAP
Closure. In map view (top), closure is the area within the deepest structural contour that forms a trapping geometry, in this case 1300 ft [390 m]. In cross section A-A', closure is the vertical distance from the top of the structure to the lowest closing contour, in this case about 350 ft [105 m]. The point beyond which hydrocarbons could leak from or migrate beyond the trap is the spill point.
DOMAL TRAP
From Schlumberger Oilfield Glossary
• Are hydrocarbons in this field oil or gas? • What is the volume of hydrocarbons In this trap?• What are the reserves?
A reservoir-drive mechanism whereby the oil is driven through the reservoir by an active aquifer. As the reservoir depletes, the water moving in from the aquifer below displaces the oil until the aquifer energy is expended or the well eventually produces too much water to be viable.
WATER DRIVE
From Schlumberger Oilfield Glossary
What is the DriveMechanism?
A gas-drive system utilizes the energy of the reservoir gas, identifiable as either as free or solution gas, to produce reservoir liquids.
GAS EXPANSION DRIVE
From Schlumberger Oilfield Glossary
What is the DriveMechanism?
Are there other drive mechanisms?
TYPES OF HYDROCARBONS
• Composition
• Molecular structure
• Physical properties
PHYSICAL PROPERTIES OF HYDROCARBONS
• Color• Refractive Index• Odor• Density (Specific Gravity)• Boiling Point• Freezing Point• Flash Point• Viscosity
FLUID DENSITY
˚ API = 141.5 ٧
= specific gravity
- 131.5
˚ API = API gravity
• What are the standard reporting conditions?
FLUID VISCOSITY
• Importance
• Units – centipoises (μ, cp)
• Strongly temperature dependent
• Standard reporting conditions
Drillship Jackup Submersible Land RigSemisubmersible
DRILLING RIGS
From Schlumberger Oilfield Glossary
From Schlumberger Oilfield Glossary
ROTARY DRILL BIT, WORN
RESERVOIR POROSITY
Definition: Porosity is the fraction of a rock that is occupied by voids (pores).
• Origins and descriptions
• Factors that effect porosity
• Methods of determination
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