This document provides an overview of petrophysics and core analysis methods. Petrophysics is the study of physical and chemical rock properties and their interaction with fluids. Key properties include lithology, porosity, water saturation, and permeability. These properties are measured through well logs, core analysis, and seismic data. Core analysis involves taking rock samples from wells and measuring properties like porosity and permeability on plugs taken from the core. The fluid content of cores can indicate hydrocarbon saturation but is altered during retrieval. Routine core analysis involves testing plugs taken along the entire reservoir section.

1. Reservoir Rock Laboratory Course (1st Ed.)

2. 1. About This Course
2. Course Learning Outcome
3. Presentation and assessment
A. Class Projects (CLS PRJ)
4. Laboratory related issues
5. Review of Syllabus
6. Resources
7. Training Outline (beta)
8. Communication

3. 1. Petrophysics
2. Coring and Plugging

5. Petrophysics definition
Petrophysics
(from the Greek petra, "rock" and physis, "nature")
is the study of physical and chemical rock properties and their
interactions with fluids.
A major application of petrophysics is in studying
reservoirs for the hydrocarbon industry.
Petrophysicists are employed
to help reservoir engineers and geoscientists
understand the rock properties of the reservoir,
particularly how pores in the subsurface are interconnected,
controlling the accumulation and migration of hydrocarbons.
Some of the key properties studied in petrophysics are
lithology, porosity, water saturation, permeability and density.
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6. key aspect of petrophysics
A key aspect of petrophysics
is measuring and evaluating these rock properties
by acquiring
well log measurements - in which a string of
measurement tools are inserted in the borehole,
core measurements - in which rock samples are
retrieved from subsurface, and
seismic measurements.
These studies are then combined with geological
and geophysical studies and reservoir engineering
to give a complete picture of the reservoir.
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7. Categories of measured properties
While most petrophysicists
work in the hydrocarbon industry, some also
work in the mining and water resource industries.
The properties measured or computed fall into
three broad categories:
conventional (or reservoir) petrophysical properties,
Reservoir models are built upon their measured and derived
properties to estimate the amount of hydrocarbon present in
the reservoir, the rate at which that hydrocarbon can be
produced to the Earth’s surface.
rock mechanical properties, and
ore quality
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8. conventional (or reservoir)
petrophysical properties,
Lithology: rock's physical characteristics:
grain size, composition and texture and etc.
By using log measurements,
such as natural gamma, neutron, density and resistivity
Porosity:
from neutrons or by gamma rays, also sonic and NMR logging.
Water saturation:
from an instrument that measures the resistivity of the rock
Permeability:
From Formation testing, and empirical relationships with
other measurements such as porosity, NMR and sonic logging.
“Net Pay”
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9. Rock mechanical properties
Some petrophysicists use acoustic and density
measurements of rocks to compute their
mechanical properties and strength.
They measure the compressional (P) wave velocity of
sound through the rock and the shear (S) wave velocity
and use these with the density of the rock to compute
the rocks' compressive strength
These measurements are useful to design programs to drill
wells that produce oil and gas.
also used to design dams, roads, foundations for buildings,
They can also be used to help interpret seismic signals from the
Earth, either man-made seismic signals or those from
earthquakes.
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10. Methods of analysis
Coring and core analysis is a direct measurement of
petrophysical properties.
In the petroleum industry rock samples are retrieved
from subsurface and measured by core labs of oil
company or some commercial core measurement
service companies.
This process is time consuming and expensive, thus cannot be
applied to all the wells drilled in a field.
Well Logging is used as a relatively inexpensive
method to obtain petrophysical properties
downhole.
Measurement tools are conveyed downhole using either
wireline or LWD method.
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12. major sources of petrophysical
properties
Knowledge of petrophysical and hydrodynamic
properties of reservoir rocks are of fundamental
importance to the petroleum engineer.
These data are obtained from two major sources:
core analysis and well logging.
In this course we present some details about the analysis of
cores and review the nature and quality of the information
that can be deduced from cores.
Cores are obtained during the drilling of a well by
replacing the drill bit with a diamond core bit and a
core barrel.
The core barrel is basically a hollow pipe receiving the
continuous rock cylinder, and the rock is inside the core barrel
when brought to surface.
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13. Coring
Continuous mechanical coring is a costly procedure due
to:
The drill string must be pulled out of the hole to replace the
normal bit by core bit and core barrel.
The coring operation itself is slow.
The recovery of rocks drilled is not complete.
A single core is usually not more than 9 m long, so extra trips
out of hole are required.
Coring should therefore be detailed programmed,
especially in production wells.
In an exploration well the coring cannot always be
accurately planned due to lack of knowledge about the
rock.
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14. sidewall coring
Now and then there is a need for sample in an
already drilled interval, and then sidewall coring can
be applied.
In sidewall coring a wireline-conveyed core gun is used,
where a hollow cylindrical “bullet” is fired in to the wall
of the hole.
These plugs are small and usually not very valuable
for reservoir engineers.
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15. The fluid content of the core
During drilling, the core becomes contaminated
with drilling mud filtrate and
the reduction of pressure and temperature
while bringing the core to surface
results in gas dissolution and further expansion of fluids.
The fluid content of the core observed on the
surface cannot be used as a quantitative measure
of saturation of oil, gas and water in the reservoir.
However, if water based mud is used the presence of oil
in the core indicates that the rock information is oil
bearing.
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16. routine core analysis
When the core arrives in the laboratory
plugs are usually drilled 20-30 cm apart throughout the
reservoir interval .
All these plugs are analyzed with respect to
porosity, permeability, saturation and lithology.
This analysis is usually called routine core analysis.
The results from routine core analysis are used in
interpretation and evaluation of the reservoir.
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17. 1. “Petrophysics.” Wikipedia, the free
encyclopedia 13 July 2014. Wikipedia. Web. 22
July 2014.
2. (KSU) M. Kinawy. “Reservoir engineering
laboratory manual" Petroleum and Natural
Gas Engineering Department, King Saud
University, Riyadh (2009).

18. 1. Without Distillation methods
2. Soxhlet Extraction method
3. Dean-Stark Distillation-Extraction
4. Conclusions and Recommendations