Porosity by saturation method
Porosity by saturation method report
Published on: Mar 4, 2016
Transcripts - Porosity by saturation method
FACULTY OF ENGINEERING
SCHOOL OF PETROLEUM AND
NAME OF EXPEREMENT:
Porosity by Saturating Method
NAME OF STUDENT:
SUPERVISED BY: Mr.Ali Kamal
Aim of Experiment:
In this test we will try to determine the porosity by using the
Knowledge of the physical properties of the rock and interaction
between hydrocarbon system and the formation rock is crucial in
understanding and evaluating the performance of a given reservoir,
porosity could be measured from the saturation method
For any porous material (for instance cores or cuttings), porosity is defined
Where the Vs is volume of solid,Vt the total (or bulk) volume and Vp the pore
volume. Porosity can be calculated using any combination of two of these
three parameters: • Volume of solid, • Volume of pores, • Bulk volume.
Volume of solid
Gas expansion pycnometer
We will come on this method later in the next section.
1- Geometrical volume
Forcylindrical cores,the total volume is generally obtained by measuring the
diameter and the length of the cylindrical sample. This method is not
applicable for pieces of cores of irregular shape.
2- Mercury pycnometer
Mercury is a non-wetting fluid with respect to air for all the rocks.
Consequently,mercury does not enter in a sample filled by air if no pressure
is applied. The mercury pycnometer method consists in measuring the
volume of mercury without and with the core immersed.
Due to safety reasons,this method is no longerused in mostof laboratories.
3- Powder pycnometer
The principle is the same as for mercury but mercury is replaced by a fine
powder. A commercial apparatus is the Geopyc from Micromeritics. The
powderis first packed in a piston using a controlled vibration and force.The
positionof the piston is measured with high accuracy (Figure 3-2). Then, the
sample is introduced in the cell, keeping the same volume of powder. The
powderis packed again under the same vibrating process and the volume of
the sample is derived from the difference in position of the piston, knowing
the section of the cell.
There are mainly more than one method and techniques to determine the
pore volume of cores here we will go through the mostpopular one which is:
Saturation method Using
Manual saturating Method
It is defined as the ratio of the volume of fluid phase (oil, water and gas) in a
given core sample to the pore volume (porosity) of the sample. The pore
volume is derived from the mass of the sample saturated with brine and after
The objective of this test is to determine the bulk volume, grain volume, pore
volume and effective porosityof interconnected pores of a core sample with
the use of liquid saturation method, (Figure 3-3).
A fluid of known density will drive into dry vacuumed sample, and the
difference between saturated and dry sample can give us the pore volume
Apparatus of experiment
The manual saturator permits to perform a sequence of vacuum and
saturation cycles on plug size samples. The standard apparatus includes a
plug sized core cell, a vacuum pump, hand operated pressure pump (2,000
psi output), a saturant vacuum tank and necessary hand operated valves
and plumbing. A larger capacity cell to accommodate full size core samples
is also available.
Equipment and sample requirements
3- Vacuum pump
5- Core saturator
6- Analytical balance
7- Core sample
1- Record the temperature in the laboratory.
2- Measure each dimension three times to take the average dimensions of
the core samples and record.
3- Measure the weight of the dry core sample.
4- Wait till the weight reading will stabilize, and record.
5- Put the core plug in the core cell chamber sample.
6- Turn on valve No.1 betweenthe vacuum pump and core sample container.
7- Close the valve No.2 between the core sample container and the brine
8- Turn on the vacuum pump.
9- When the vacuum pressure will be stable, wait for 2 minute and then turn
off vacuum pump.
10- Open valve No.2 to allow brine to flow to the core sample container.
11- Once the liquid level in the saturant vacuum tank takes it is stabile level,
then turn off valve No.2. and vacuum pump.
12-Start to pressurize the core chambercell manually and slowly up to 2000
13-Monitor and keep the pressure on2000psi till it will stabilize on this value.
14- Waite for 5 minute.
15- Open valve. No.2 and wait for the pressure gauge to go back to Zero
16- Gently take out the core sample and wipe out the liquid on the sample
surface by rolling it on a piece of paper.
17- Measure and record the weight of the saturated core sample.
18- Measure the difference and find the pore volume and Porosity.
Q: Discuss what type of porosity you found and why?
Effective porosity measured on core samples which are dried in a
humidity oven so that clays retain one or two molecular layers of
bound water—however, this CBW tends to a minimum and is likely
not reservoir representative.
Q: Why we take the core plugging?
-We take the core plug to determined the physical properties of the
rock like (porosity ,permeability ,saturation ,capillary pressure
,surface & interfacial tension &…..so on).
Q: What are the objectives porosity?
-To measure the volume of oil in place &gas in place,and many
Result of Experiment
Report the porosity value or the sample to the nearest 0.1%.
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