Petroleum engineering lab report

1. College of Engineering
Faculty of petroleum Engineering
Reservoir Rock Properties Laboratory
PENG211L
Helium Porosimeter
Name: Ruba Alsoheil
ID: 201801530
Submitted to: Dr. Jamil Mahfoud
Date: 11-18-2020

2. Table of Content:
List of Figures……………………………………………………………………………………...i
List of Tables……………………………………………………………………………………....ii
Chapter 1: Introduction
1.1 Theory and Definitions………………………………………………………………………...1
1.2 Objectives……………………………………………………………………………………...2
Chapter 2: Apparatus………………………………………………………………….…………...3
Chapter 3: Other Equipment..……………………………………………………………………..4
Chapter 4: Procedure………………………………………………………………………………7
Chapter 5: Calculation……………………………………………………………………………..9
Chapter 6: Results and Discussion
6.1 Table of Results……………………………………………………………………………...12
6.2 Discussion…………………………………………………………………………………....12
Chapter 7: Errors and Recommendation
7.1 Errors…………………………………………………………………………………………14
7.2 Recommendation……………………………………………………………………………..14
Chapter 8: Conclusion……………………………………………………………………………16
References………………………………………………………………………………………..17

3. i
List of Figures:
Figure 2.1: Helium cylinder………………………………………………………………………3
Figure 3.1: Helium Cylinder…………………………………………………………...…………4
Figure 3.1: Core samples…………………………………………………………………………4
Figure 3.2: O-rings sample……………………………………………………………………….5
Figure 3.3: Spacers……………………………………………………………………………….5
Figure 3.5: Ruler………………………………………………………………………………….6

4. ii
List of Tables:
Table 5.1: Variations of volume and pressure throughout an isothermal experiment……………9
Table 5.2: Different properties of different cores…………………………………………………9
Table 5.3: Different properties of various spacers…………………………………………..……9
Table 5.4: Different properties of different O-rings………………………………………….…..9
Table 6.1: Effective porosity of various kinds of cores at a constant temperature 21ºc…………..12

5. 1
Chapter 1: Introduction
1.1 Theory and definition:
Oil and gas are a very crucial energy sources, so exploration with the purpose of producing
them is very important. However, drilling wells for oil is very expensive, for the cost for an
onshore well ranges between 4.9 and 8.3 million dollars (OilScams, 2020). So, petrophysical
properties like porosity and permeability which can be estimated using core samples helps in
understanding features related to the reservoir rocks Porosity indicate the ratio or the
percentage of the volume of voids with respect to the whole volume of the rock (Ganat, 2020).
Furthermore, there are different types of porosity including primary porosity which is mainly
related to the depositional, secondary porosity related to the reactions which lead to the
particles dissolvements, fracture porosity that is due to tectonic plates moving and fracturing
the rocks. The most vital type in the oil and gas industry is effective porosity where the pores
are connected to each other facilitating and allowing the passage of the fluid. In other words,
the voids are not isolated from each other. This parameter is significant for a better
comprehension of the characteristics and the behavior of the reservoir (schlumberger, 2012).
During the exploration of hydrocarbon, evaluating the effective porosity of the core samples
and comparing it to other accumulated data like viscosity helps in classifying if a certain
reservoir could be a potential commercial reserve.
In order to know the volume of the fluid that can be stored in the pores, there are different
methods including vacuum or fluid saturation and X-ray CT scanning (Dandekar, 2013). In
this report the method of deriving porosity using helium porosimeter is implied.
𝚽 =
𝑉𝑣𝑜𝑖𝑑
𝑉𝑏𝑢𝑙𝑘

6. 2
Moreover, helium gas is used due to its low mass, small sized particles, and that it does not
react with the particle of the rock (Dandekar, 2013). Also, it has characteristics like
compressibility, factor is equal to 1, which stay approximately unchanged with various
temperatures and pressures (Dandekar, 2013). According to Boyle’s law, formula, 𝑃1𝑉𝑟𝑒𝑓 =
𝑃2𝑉2 which aids in finding the volume of helium in the core chamber.
1.2: Objective: The main purpose is to derive ta petrophysical property which is effective porosity
of different types of cores like Indiana.

7. 3
Chapter 2: Apparatus
Figure 2.1: Helium porosimeter
▪ Helium supply valve: allow the passage of helium particles to helium porosimeter
▪ 3-way valve: allow the helium particles to pass to the core chamber and aid in venting the
system
▪ Temperature and pressure readout: give the values of the pressure and temperature
▪ Core chamber: place to put core and appropriate spacer and O-ring to measure porosity
▪ Cap: Stoppage of the particle of helium from escaping the chamber
▪ Channels: transportations for the gas particles
Core chamber
Temperature and
pressure readouts
3-way valve
Helium
supply valve
cap
𝑉𝑟𝑒𝑓

8. 4
Chapter 3: Other Equipment
Figure 3.1: Helium cylinder
▪ Helium cylinder: The main and only supplier of Helium gas to the porosimeter.
`
Figure 3.2: Core samples
Torrey
Indiana
Dolomite
Berea

9. 5
▪ Sample of the core which are put in the core chamber to measure the porosity. They are
Berea, Dolomite, Indiana, and Torrey.
▪
Figure 3.3: O-rings sample
▪ O-rings: They are hollow cylinders used to make the core fit in the chamber without
leaving any space. Berea is the smallest core, so O-ring1 is used. The other cores like
Indiana, O-ring2 is used.
Figure 3.4: Spacers
▪ Spacers: There are different types of spacers. They are used to fill the empty volume which was
unfilled by the core in the core chamber.
1

10. 6
Figure 3.5: Ruler
Ruler: Dimensions like length and radii of the core, spacers, and O-rings are measured.

11. 7
Chapter 4: Procedure
▪ At the beginning of the experiments helium cylinder valve is closed, 3-way valve is in vent
position, helium supple valve is in horizontal position
▪ Turn the apparatus, helium porosimeter, ON
▪ Check the pressure reading which should be zero
▪ If the value of the pressure reading was greater than zero, this indicates helium particles is
left from previous experiment
▪ To make the pressure reading zero, rotate the 3-way valve 180º down and 180º up several
time to vent the system from helium
▪ Then retrieve the valve to its initial position
▪ Rotate the cap in a counter clockwise motion to open the cap
▪ Clean the core chamber using a tissue to remove any dust and impurities
▪ Use the core, Indiana
▪ Measure its diameter and length
▪ Then choose appropriate O-ring and spacers after measuring and comparing their length
and diameter with the core chosen, Indiana
▪ Fit O-ring-2 around Indiana
▪ Then slide them in the core chamber
▪ Place the appropriate spacing, spacer-1, in the chamber
▪ Close it by the chamber’s cap
▪ After opening the helium cylinder valve, the pressure remains zero
▪ Rotate the helium supply valve with a 90º angle downward to ensure that it opens
▪ The pressure escalates due to helium particles entering the reference chamber

12. 8
▪ After around five minutes, write down the value of the pressure after it becomes constant
▪ Stop the helium’s supply by closing the helium supply valve
▪ Record the volume
▪ Helium particles enter the core chamber by opening the 3-way valve by turning it in 180º
angle in a downward position
▪ The pressure deescalates
▪ After the pressure value stops fluctuating, record it
▪ Vent the system by turning the 3-way valve in a downward motion by a 180º angle, then
turn it upward by the same angle
▪ Repeat it several time, until pressure is zero
▪ Remove the cap, spacers, and the core, Indiana
▪ Put the spacers and the O-ring in their specified bags
▪ All the valves should be in the same way they were positioned initially, closed
▪ Turn Off the apparatus

13. 9
Chapter 5: Calculation
Table 5.1: Variations of volume and pressure throughout an isothermal experiment
Core 𝑃1 (psi) 𝑃2 (psi) 𝑉1 (𝑐𝑚3
) 𝑉2(𝑐𝑚3
)
Berea 11 8.3 30.7 40.7
Silurian
Dolomite 11 10 30.7 33.8
Indiana 11 8.7 30.7 38.82
Torrey 11 9.5 30.7 35.55
Table 5.2: Different properties of different cores
Core Diameter (cm) Length (cm) 𝑉𝑏𝑢𝑙𝑘(𝑐𝑚3
)
Berea 2.5 3.7 18.15
Silurian
Dolomite 2.5 5 24.53
Indiana 2.5 5 24.53
Torrey 2.5 5 24.53
Table 5.3: Different properties of various spacers
Spacer Diameter (cm) Length (cm) Volume (𝑐𝑚3
)
1 3.7 2.5 26.86
2 3.7 1.2 12.89
Table 5.4: Different properties of different O-rings
O-ring
Outer diameter
(cm)
Inner Diameter
(cm) Length (cm) Volume (𝑐𝑚3
)
1 3.7 2.5 3.7 21.61
2 3.7 2.5 5 29.20
Calculations to show the effective porosity for Indiana Core Sample
The first step is to apply Boyle’s equation to know the 𝑉2 which is the addition of the reference
volume, the volume of the pores, and the volume where helium particle entered due to voids
between the spacer and the core which is commonly known as dead volume.

14. 10
𝑃1𝑉𝑟𝑒𝑓 = 𝑃2𝑉2 => 𝑉2 =
11×30.7
8.7
𝑉2 = 38.82 𝑐𝑚3
Then, procced and calculate the bulk volume of the rock, Indiana.
𝑉𝐵𝑢𝑙𝑘 = 𝜋 (
𝐷
2
)
2
𝐿
▪ D as in the Indiana’s diameter in 𝑐𝑚3
▪ L as in Indiana’s length in 𝑐𝑚
𝑉𝐵𝑢𝑙𝑘 = 𝜋 (
𝐷
2
)
2
𝐿= 3.14×(
2.5
2
)
2
× 5 = 24.53 𝑐𝑚3
Proceed calculating the volumes of the appropriate Spacer and O-ring.
𝑉𝑠𝑝𝑎𝑐𝑒𝑟1 = 𝜋 (
𝐷
2
)
2
𝐿= 3.14×(
3.7
2
)
2
× 2.5 = 26.86 𝑐𝑚3
𝑉𝑂−𝑟𝑖𝑛𝑔2 = 𝜋(
𝐷𝑜
4
2
−
𝐷𝑖
4
2
)𝐿 = 𝜋(
3.7
4
2
−
2.5
4
2
)𝐿= 29.2 𝑐𝑚3
▪ 𝐷𝑜 𝑖𝑠 𝑡ℎ𝑒 𝑂 − 𝑟𝑖𝑛𝑔 2′
𝑠 𝑜𝑢𝑡𝑒𝑟 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟
▪ 𝐷𝑖 𝑖𝑠 𝑡ℎ𝑒 𝑂 − 𝑟𝑖𝑛𝑔 2′
𝑠 𝑖𝑛𝑛𝑒𝑟 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟
Now, sum the volumes calculated in order to know the volume of the chamber.
𝑉𝐶ℎ𝑎𝑚𝑏𝑒𝑟 = 𝑉𝐵𝑢𝑙𝑘 + 𝑉𝑠𝑝𝑎𝑐𝑒𝑟1 + 𝑉𝑂−𝑟𝑖𝑛𝑔2
𝑉𝐶ℎ𝑎𝑚𝑏𝑒𝑟 = 𝑉𝐵𝑢𝑙𝑘 + 𝑉𝑠𝑝𝑎𝑐𝑒𝑟1 + 𝑉𝑂−𝑟𝑖𝑛𝑔2 = 24.53 + 26.86 + 29.2= 80.59 𝑐𝑚3
Apply the following equation to derive the volume of Indiana’s grains
𝑉2 = 𝑉𝑟𝑒𝑓 + 𝑉
𝑝𝑜𝑟𝑒
𝑉2 = 𝑉𝑟𝑒𝑓 + 𝑉𝑐ℎ𝑎𝑚𝑏𝑒𝑟- (𝑉𝑔𝑟𝑎𝑖𝑛𝑠 + 𝑉𝑠𝑝𝑎𝑐𝑒𝑟1 + 𝑉𝑂−𝑟𝑖𝑛𝑔2)
𝑉𝑔𝑟𝑎𝑖𝑛𝑠 = 𝑉𝑟𝑒𝑓 + 𝑉𝑐ℎ𝑎𝑚𝑏𝑒𝑟- (𝑉2 + 𝑉𝑠𝑝𝑎𝑐𝑒𝑟1 + 𝑉𝑂−𝑟𝑖𝑛𝑔2)
𝑉𝑔𝑟𝑎𝑖𝑛𝑠= 30.7 + 80.6 – (38.82 + 26.86 + 29.202) = 16.41 𝑐𝑚3
After knowing the value of the volume of the grains, the volume of the pore is derived by

15. 11
𝑉
𝑝𝑜𝑟𝑒 = 𝑉𝐵𝑢𝑙𝑘 − 𝑉𝑔𝑟𝑎𝑖𝑛𝑠
𝑉
𝑝𝑜𝑟𝑒 = 24.53 − 16.41 = 8.12 𝑐𝑚3
This leads to the final step of calculating the effective porosity ratio of Indiana is 𝚽:
Φ =
𝑉𝑣𝑜𝑖𝑑
𝑉𝑏𝑢𝑙𝑘
=
8.12
24.53
= 0.33 ( 33.6%)

16. 12
Chapter 6: Results and discussion:
6.1 Results:
Table 6.1: Effective porosity of various kinds of cores at a constant temperature 21ºc
Core
Effective porosity 𝚽
𝑉𝐵𝑢𝑙𝑘 (𝑐𝑚3
) 𝑉𝑔𝑟𝑎𝑖𝑛 (𝑐𝑚3
) 𝑉
𝑝𝑜𝑟𝑒 (𝑐𝑚3
)
percentage(%) ratio
Berea 49.09 0.49 18.15 9.24 8.91
Indiana 33.10 0.33 24.53 16.42 8.12
Torrey 19.53 0.19 24.53 19.74 4.79
Silurian Dolomite 12.60 0.12 24.53 21.44 3.09
6.2 Discussion:
The table shows the cores in decreasing order of effective porosity where Berea has the maximum
effective porosity (49.09 %) and Dolomite has the minimum effective porosity (12.6%) compared
to other rocks. It is worth mentioning that Indiana’s effective porosity is 33.10%.
Also, the volume of the grains is inversely proportional with the effective porosity, for when the
𝑉𝑔𝑟𝑎𝑖𝑛 increases the 𝑉
𝑝𝑜𝑟𝑒 decreases.
There are many factors which plays a huge role in determining the percentage of porosity in a rock.
The factors are the particle size and shape, sorting, and packing (Ganat, 2020). When the particles
are round, have uniform or similar sizes, and are sorted in an organized manner, porosity will
increase. For instance, rhombohedral sorting has a very low porosity in comparison with other
ways of arrangement. Also, cementation, dissolution, and compaction play a huge role in
determining the percentage of porosity.
Additionally, the type of rock whether it is igneous, metamorphic, or sedimentary affects porosity.
For instance, metamorphic and igneous rocks’ porosity is very low and small, while in limestone-

17. 13
based rocks effective porosity depends mainly on fractures (Ganat,2020). Moreover, sedimentary
reservoir contains carbonate rocks that include various kinds of porosity as in primary and
secondary (Mukherjee & Das, 2020). Then, effective porosity ratio of sandstone can reach 0.4
which is more than carbonate ,0.25 (Woods & Morton-Thompson, 2020). Thus, relating the
previous statement to the table above assure the fact that the highest ratio is Berea, sandstone, and
the lowest is Silurian Dolomite, carbonate.
`

18. 14
Chapter 7: Errors and Recommendation
7.1 Errors:
▪ Miscalculating the diameter and length of the core which leads to different Bulk volume,
so an inaccurate ϕ
▪ The core might not be a “perfect cylinder” where it can have fractured edges, so inexact ϕ
will be derived.
▪ Presence of small particles of dust in the chamber that increases the inaccuracy of the ϕ
▪ Helium particle might still be present in core chamber or channels, residuals, due to a
previous experiment which leads to a lot of calculation error.
The pressure readout was not calibrated as in the value was not zero at the start of the
experiment.
▪ The spacers do not fit well in the core chamber and leaves space ( 𝑉𝐶ℎ𝑎𝑚𝑏𝑒𝑟/𝑏𝑒𝑟𝑒𝑎 =
79.6𝑐𝑚3
) or the O-ring’s outer space is a little bit bigger than that of the core which allows
the passage of helium gas particle which increases porosity.
▪ Not waiting until the pressure is constant to record the value of the pressure
7.2 Recommendation:
▪ Focus when measuring the core, spacers, and O-ring
▪ Try to choose a perfect cylinder core with no ripped edges or decrease the volume to
eliminate the fractured edges
▪ Cleaning the core chamber solves the inaccuracy
▪ Vent the chamber to eliminate helium residuals using the 3-way valve similar to what was
done in the procedure

19. 15
▪ Remember to check if the pressure readout was zero before opening the helium supply
valve
▪ Take into consideration the error and add or subtract any uncertainty after deriving the
calculations
▪ Wait at least five minutes until the pressure read out is constant

20. 16
Chapter 8: Conclusion
Knowing the porosity of the rock especially the reservoir rocks helps in taking the decision of
whether the oil or the gas in the reservoir is enough to be extracted. In general cases, when the
effective porosity ratio is bigger than 0.25, it can be denoted as good porosity. So, oil is not
produced in sandstone rocks when the ratio is less 0.08 and less than 0.08 in limestone (Harraz,
2019). There are a lot of process that decrease porosity’s factor including cementation and
compaction, and many factors which increase it like packing and sorting (Harraz, 2019). To end,
this parameter is vital and significant in petroleum industry to understand the reservoir’s dynamics
and to make geophysical models.

21. 17
References
▪ Dandekar, A. Y. (2013). Petroleum Reservoir Rock and Fluid properties. London: Taylor&
Francis.
▪ Ganat, T. A. O. (2020). Fundamentals of Reservoir Rock properties. Malaysia: Springer.
▪ Harraz, H. Z. (2019). Porosimeter of Hydrocarbon Reservoir. Economic Petroleum,
DOI: 10.13140/RG.2.2.33720.90886
▪ Mukherjee, S. &, Das, T. (2020). Porosity in carbonate. Emilie Du Châtelet und die
deutsche Aufklärung
▪ DOI: 10.1007/978-3-030-13442-6_2
▪ OilScams. (2020). How much does an oil and gas well cost? Retrieved from:
http://www.oilscams.org/how-much-does-oil-gas-well-
cost#:~:text=According%20to%20the%20U.S.%20Energy,gathering%20processing%20a
nd%20transport%20costs.
▪ Schlumberger. (2020). Oil Field Glossary. Retrieved from:
https://www.glossary.oilfield.slb.com/en/Terms/t/toc.aspx
▪ Woods, A. M., & Morton-Thompson, D. (2020). ME10: Development Geology Reference
Manual. Retrieved from: http://archives.datapages.com/data/alt-browse/aapg-special-
volumes/me10.htm