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[en] FLOW OF PSEUDOPLASTIC FLUID IN ANNULAR WITH VARIABLE ECCENTRICITY / [pt] ESCOAMENTO DE UM LÍQUIDO PSEUDOPLÁSTICO EM ESPAÇO ANULAR COM EXCENTRICIDADE VARIÁVELVICTOR MANUEL CARDENAS TARAZONA 28 July 2006 (has links)
[pt] O estudo de escoamentos em espaço anular é de fundamental
importância
para o entendimento e otimização do processo de perfuração
de poços. A lama de
perfuração deve possuir propriedades reológicas e
termofísicas tais que garantam
um bom desempenho no carreamento de cascalho, na
lubrificação e refrigeração
das brocas, na limpeza do poço, manutenção da pressão da
coluna de líquido para
equilibrar a pressão das formações atravessadas e
estabilizar as paredes do poço.
Uma análise completa desta situação é extremamente
complexa; o cilindro interno
(coluna) pode estar girando, a geometria da parede do poço
não é um cilindro
perfeito, o espaço anular é excêntrico e a excentricidade
varia ao longo do poço.
Além disto, lamas de perfuração possuem um comportamento
pseudoplástico, isto
é a viscosidade é função decrescente da taxa de
deformação. Os modelos que
levam em conta todos esses fatores são extremamente
complexos e caros
computacionalmente. Os modelos disponíveis na literatura
utilizam hipóteses
simplificadoras para tornar a análise menos complexa.
Muitos trabalhos
consideram a rotação do cilindro interno e o comportamento
não Newtoniano,
mas desprezam a variação da excentricidade ao longo do
poço. Mesmo com esta
simplificação, os modelos apresentados, que consistem na
solução da equação bidimensional
para determinar o campo de velocidade axial e tangencial do
escoamento desenvolvido em um espaço anular, possuem alto
custo
computacional. O modelo apresentado neste trabalho leva em
conta a variação da
excentricidade ao longo do poço, bem como o comportamento
pseudoplástico da
lama e a rotação do cilindro interno. As equações que
governam o problema
foram simplificadas utilizando a teoria de lubrificação.
As equações diferenciais parciais que descrevem o perfil
de velocidade e a pressão ao longo do poço foram
resolvidas pelo método de diferenças finitas (diferenças
centrais) e linearizadas
pelo método de Newton. O modelo de lubrificação foi
validado através da
comparação dos resultados obtidos com trabalhos na
literatura para escoamentos
com excentricidade constante. Os resultados mostram o
efeito da variação da
excentricidade ao longo do poço, da rotação na coluna, das
propriedades não
Newtonianas no padrão do escoamento e no fator de atrito. / [en] Helical flow in annular space occurs in drilling operation
of oil and gas
wells. The correct prediction of the flow of the drilling
mud in the annular space
between the wellbore wall the the drill pipe is essential
to determine the variation
in the mud pressure within the wellbore, the frictional
pressure drop and the
efficiency of the transport of the rock drill cuttings. A
complete analysis of this
situation is extremely complex; the inner cylinder is
usualy rotating, the wellbore
wall will depart significantly from cylindrical, during
driling operation the drill
pipe is eccentric, and the eccentricity varies with
position along the well.
Moreover, drilling muds present pseudoplastic behavior,
the viscosity is a strong
function of the deformation rate. A complete analysis of
this situation would
require the solution of the three-dimensional momentum
equation and would be
computationally expensive and complex. Models available in
the literature to
study this situation do consider the rotation of the inner
cylinder and the non
Newtonian behavior of the liquid, but assume the position
of the inner and outer
cilinders fixed, i.e. they neglect the variation of the
eccentricity along the length
of the well, and assume the flow to be well developed.
This approximation leads
to a two-dimensional model to determine the three
components of the velocity
field in a cross-section of the annulus. The resulting
differential equations have
to be solved by some numerical method. The model presented
in this work takes
into account the variation of the eccentricity along the
well; a more appropriate
description of the geometric configuration of directional
wells. As a consequence,
the velocity field varies along the well length and the
resulting flow model is
three-dimensional. Lubrication theory is used to simplify
the governing equations into a non-linear, two-dimensional
Poisson Equation that describes the pressure
field. Lubrication model was validated by comparing the
predictions to reported
results on fully developed flow on eccentric annular
space. The results show the
effect of varying eccentricity, non Newtonian behavior and
inner cylinder rotation
on the flow field and on the friction factor.
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Automated Device to Measure Slurry Properties in Drilled ShaftsMullins, Miles Patrick 01 July 2016 (has links)
Slurry is the fluid within a drilled excavation that is introduced when an excavation is deeper than the water table or where additional stability is needed for loose sandy dry soils. Although construction practices vary greatly throughout the country and the world, slurry levels should be maintained above the existing ground water level by a suitable margin. The most widely used slurry type is mineral slurry formed by mixing dry clay powder with water; either bentonite or attapulgite powder may be used (attapulgite being used in saline water conditions). Regardless of whether the slurry material is mineral, polymer or natural, the construction practice must address the slurry properties to ensure the stability of the excavation is never compromised.
Proper performance of slurries used to stabilize drilled shaft excavations is maintained by assuring the density, viscosity, pH, and sand content stay within specified limits. These limits have been set either by past experience, research findings and/or by manufacturer recommended values. However, field slurry testing is time consuming as all measurements are manually performed. With the overwhelming advances in digital down-hole devices, it is not unreasonable to assume that slurry property tests are equally applicable to this trend. This formed the basis of this project.
The most commonly used test to indicate slurry viscosity is the Marsh Funnel Test which is essentially a timed flow for a fixed volume of slurry to exit a falling head funnel. Using a library of unique pressure versus flow rate responses for a wide range of slurry viscosities, an automated downhole device was designed and tested that incorporated this information to estimate viscosity in the excavation without the need to remove slurry in order to test. Direct measurement of slurry density was also incorporated into the device and the sand content was computed from density and the viscosity where the suspended solids that make up the density stems from both the slurry products and the soil cuttings.
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Tundra vegetation recovery on 30 year-old seeded and unseeded drilling mud sumps in the Mackenzie River Delta region, NWTWunderlich, Nicole Bettina 08 April 2010
Oil and gas exploration conducted in the 1970s left behind a legacy of abandoned well sites in the Mackenzie Delta region of northern Canada, including several in the Kendall Island Migratory Bird Sanctuary and surrounding areas. Evidence of 30 year-old well sites is present in the form of drilling mud sumps, which are mounds of disturbed tundra that contain frozen drilling-wastes. One to two years after the wells were decommissioned some of the sites were seeded with non-native grass species and fertilized to test whether these treatments could accelerate vegetation recovery and prevent erosion. The main objective of this research was to examine the long-term impact of post-disturbance seeding treatments on the vegetation recovery of drilling mud sumps.<p>
Surveys of vegetation composition and environmental conditions at 12 sump sites (6 seeded and 6 unseeded) showed that, after over 30 years of recovery, seeded sumps in the Mackenzie Delta did not significantly differ from those left for natural recovery. However, seeded and previously introduced grasses <i>Festuca rubra</i> and <i>Poa pratensis</i> were found on both seeded and unseeded sumps. The undisturbed surrounding tundra seems to be resistant to invasion by these introduced grasses. However, these species could become invasive in the future, particularly in the context of warming in the North and increasing anthropogenic disturbance. The results of this study contribute valuable information on the long-term effects of revegetation treatments that is critical for making informed management decisions about the rehabilitation of industrial disturbances in the Arctic.
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Tundra vegetation recovery on 30 year-old seeded and unseeded drilling mud sumps in the Mackenzie River Delta region, NWTWunderlich, Nicole Bettina 08 April 2010 (has links)
Oil and gas exploration conducted in the 1970s left behind a legacy of abandoned well sites in the Mackenzie Delta region of northern Canada, including several in the Kendall Island Migratory Bird Sanctuary and surrounding areas. Evidence of 30 year-old well sites is present in the form of drilling mud sumps, which are mounds of disturbed tundra that contain frozen drilling-wastes. One to two years after the wells were decommissioned some of the sites were seeded with non-native grass species and fertilized to test whether these treatments could accelerate vegetation recovery and prevent erosion. The main objective of this research was to examine the long-term impact of post-disturbance seeding treatments on the vegetation recovery of drilling mud sumps.<p>
Surveys of vegetation composition and environmental conditions at 12 sump sites (6 seeded and 6 unseeded) showed that, after over 30 years of recovery, seeded sumps in the Mackenzie Delta did not significantly differ from those left for natural recovery. However, seeded and previously introduced grasses <i>Festuca rubra</i> and <i>Poa pratensis</i> were found on both seeded and unseeded sumps. The undisturbed surrounding tundra seems to be resistant to invasion by these introduced grasses. However, these species could become invasive in the future, particularly in the context of warming in the North and increasing anthropogenic disturbance. The results of this study contribute valuable information on the long-term effects of revegetation treatments that is critical for making informed management decisions about the rehabilitation of industrial disturbances in the Arctic.
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Designing Lost Circulation Pills For Polymer Based Drill-in FluidsKahvecioglu, Alper 01 December 2008 (has links) (PDF)
Specially designed non-damaging lost circulation pills (LCP) are being effectively applied for drilling depleted zones worldwide. Optimizing the LCP compositions stop the lost circulation effectively and protect the production zone from liquid and solids invasion significantly. Shape, particle size distribution and concentration of the lost circulation materials (LCM) are key parameters determining the effectiveness of LCP. In this study, the Permeability Plugging Apparatus (PPA) is utilized to evaluate effectiveness of various LCM&rsquo / s in curing the lost circulation. Sized calcium carbonates are used as LCM in different concentrations and in different particle size distribution. Lost circulation zones are simulated using the ceramic disks and slotted disks. Ceramic disks with nominal pore sizes 20, 35, 60, 90, and 150 microns are characterized in terms of pore size distribution using the computerized image analysis technique. Filter cake quality, spurt loss and filtrate volume are basic parameters to be evaluated in this study. Tests are performed at 75 F and 300 psi of differential.
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Evaluating Leachability of Residual Solids Generated from Unconventional Shale Gas Production Operations in Marcellus ShaleSharma, Shekar 17 September 2014 (has links)
Hydraulic fracturing operations utilized for shale gas production result in the generation of a large volume of flowback and produced water that contain suspended material, salts, hydrocarbons, metals, chemical additives, and naturally-occurring radioactive material. The water is impounded at drilling sites or treated off-site, resulting in significant generation of residual solids. These are either buried on site or are disposed in lined landfills. The objective of this study was to determine the levels of heavy metals and other elements of concern that will leach from these residual solids when placed in typical disposal environments.
For this purpose, laboratory leaching experiments were employed wherein representative samples were brought into contact with a liquid to determine the constituents that would be leached by the liquid and potentially released into the environment. The samples used included sludge resulting from the physicochemical treatment of process water (TS), sludge solidified with cement kiln dust (SS), raw solids obtained by gravity separation of process water (RS), and drilling mud (DM). The samples were subjected to both single extraction (i.e. Shake Extraction Test, SET) and multiple extraction (i.e. Immersion Test, IT) leaching tests. For the shake extraction test, samples were mixed with a specific amount of leaching solution without renewal over a short time period. In the immersion test, samples were immersed in a specific amount of leaching solution that was periodically renewed over a longer period of time. For both these tests, analyses were performed on the filtered eluate. The tests were performed as per standards with modifications. Distilled de-ionized water, synthetic acid rain (pH ~ 4.2), weak acetic acid (pH ~ 2.88), and synthetic landfill leachate were used as leaching solutions to mimic specific disposal environments.
Alkali metals (Li, K, Na), alkaline earth metals (Ba, Ca, Mg, Sr) and a halide (Br), which are typically associated with Marcellus shale and produced waters, leached at high concentrations from most of the residual solids sample. The SS sample, due to its stabilization with CKD, had a lower extraction efficiency as compared to the unconsolidated TS and RS samples. In EF 2.9 and EF SLL, the leaching took place under acidic conditions, while for EF DDI and EF 4.2, the leaching occurred in alkaline conditions. EF 2.9 and EF SLL were determined to be the most aggressive leaching solutions, causing the maximum solubility of most inorganic elements. Thus, high amounts of most EOCs may leach from these residual solids in MSW landfills disposed under co-disposal conditions. Agitation, pH and composition of the leaching solution were determined to be important variables in evaluating the leaching potential of a sample.
The results of this study should help with the design of further research experiments being undertaken to develop environmentally responsible management/disposal strategies for these residual solids and also prove useful for regulatory authorities in their efforts to develop specific guidelines for the disposal of residuals from shale gas production operations. / Master of Science
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Impact assessment of the environmental protection policies in the upstream oil industry in Nigeria / A.M. Bayagbon.Bayagbon, Anthony Mamurhomu January 2011 (has links)
The need for energy and the associated economic benefits from the oil and gas deposits found mainly in
the Niger Delta region of Nigeria necessitated the exploration and exploitation activities being carried
out by the oil and gas Companies. However, these exploration and exploitation activities due to their
unpredictable nature have a huge potential for environmental pollution as been experienced in the form
of oil spills, gas flaring, irresponsible disposal of waste and several other activities that have resulted in
the environmental degradation of the Niger Delta region.
In the light of these, the Federal Government of Nigeria having experienced the consequences of
pollution of the environment during the Koko Toxic Waste Dump incident in the then Bendel State in
1987 established a regulatory body tasked with the responsibility of harmonizing the economic interest
from the oil and gas exploration and exploitation activities with the sustainability of the natural
environment by developing well structured and articulated policies aimed at guiding the operations of
the oil and gas operators, track their compliance and administer appropriate punitive measures for non
compliance.
However, this research work which is aimed at evaluating the impact of the environmental protection
policies in upstream oil and gas activities in the Niger Delta region, involved the use of questionnaires
and interviews. These questionnaires were completed by the management and staff of three major oil
and gas companies operating within the area, the Department of Petroleum Resources and members of
the Host communities. The interview was carried out to provide relevant feedback on their assessment
of the impact made by the environmental protection policies on the upstream oil and gas activities in
their operational areas/host communities.
The study however concluded that “Although there is a regulatory body tasked with the responsibility to
develop, implement and track compliance of the environmental protection policies in the upstream oil
industry, the body is ineffective and as such the impact of the environmental protection policies is
inadequate.
Appropriate informed recommendations on the improvement strategies to the identified gaps that
resulted in the unfavorable conditions were also provided. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2011
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Impact assessment of the environmental protection policies in the upstream oil industry in Nigeria / A.M. Bayagbon.Bayagbon, Anthony Mamurhomu January 2011 (has links)
The need for energy and the associated economic benefits from the oil and gas deposits found mainly in
the Niger Delta region of Nigeria necessitated the exploration and exploitation activities being carried
out by the oil and gas Companies. However, these exploration and exploitation activities due to their
unpredictable nature have a huge potential for environmental pollution as been experienced in the form
of oil spills, gas flaring, irresponsible disposal of waste and several other activities that have resulted in
the environmental degradation of the Niger Delta region.
In the light of these, the Federal Government of Nigeria having experienced the consequences of
pollution of the environment during the Koko Toxic Waste Dump incident in the then Bendel State in
1987 established a regulatory body tasked with the responsibility of harmonizing the economic interest
from the oil and gas exploration and exploitation activities with the sustainability of the natural
environment by developing well structured and articulated policies aimed at guiding the operations of
the oil and gas operators, track their compliance and administer appropriate punitive measures for non
compliance.
However, this research work which is aimed at evaluating the impact of the environmental protection
policies in upstream oil and gas activities in the Niger Delta region, involved the use of questionnaires
and interviews. These questionnaires were completed by the management and staff of three major oil
and gas companies operating within the area, the Department of Petroleum Resources and members of
the Host communities. The interview was carried out to provide relevant feedback on their assessment
of the impact made by the environmental protection policies on the upstream oil and gas activities in
their operational areas/host communities.
The study however concluded that “Although there is a regulatory body tasked with the responsibility to
develop, implement and track compliance of the environmental protection policies in the upstream oil
industry, the body is ineffective and as such the impact of the environmental protection policies is
inadequate.
Appropriate informed recommendations on the improvement strategies to the identified gaps that
resulted in the unfavorable conditions were also provided. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2011
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Development and testing of alternative methods for speeding up the hydraulic data transmission in deep boreholesBerro, Mouhammed Jandal 15 February 2019 (has links)
For developing the available hydrocarbon reserves and for exploring new reservoirs, deeper and more complex wells are drilled. Drilling such deeper and complex wells requires a constant monitoring and controlling of the well paths. Therefore, the bottom hole assembly, the lower section of the drill string above the drill bit, is equipped with numerous measuring sensors for collecting geological and directional data while drilling. The collected data have to be transmitted to the surface in real time.
Prior to transmit the data measured downhole to the surface, they are processed and translated into a binary code. Accordingly, the data will be represented as a series of zeroes and ones. The most common method for data transmission in boreholes is the so called mud pulse telemetry which sends the information through the drilling mud inside the drill string by means of coded pressure pulses. There are two types of devices available for downhole pressure pulses generation. The first type is the (positive or negative) pressure pulser which transmits the data by quasi-static variations of the pressure level inside the drill string. The second type is the (rotating or oscillating) mud siren which transmits the data by generating continuous pressure waves at specific frequencies.
The main disadvantage of the mud pulse telemetry is its low data transmission rate which is about 10 bps. This data rate is very low compared to the measured amount of raw data. Therefore, the efficiency of the mud pulse telemetry must be improved, so that the data could be transmitted at higher rates. The present research work presents different developed and tested concepts for increasing the efficiency and the data transmission rate of the mud pulse telemetry. Both, the transmitter and the receiver end, were taken into consideration by developing the new concepts. Different hardware and software tools were used for performing the present research work. The available flow loop test facility and the experimental prototypes of the mud siren and positive pulser were used. The test facility was extended in order to enable the investigation of the new concepts. The available 3D numerical model (ANSYS CFX) was modified and extended in order to study the new concepts.
At the transmitter end, a novel concept for a hybrid mud pulse telemetry system was developed and successfully tested. Here, two different types of mud pulse telemetry could be used in a combination, such as a mud siren and a pressure pulser. The developed concept was registered at the German Patent and Trade Mark Office for a patent in 2018. Two concepts for a multi-frequency mud siren were developed for simultaneous generation of two frequencies. In the first approach, two sets of stator/rotor were installed in a row connection, while they were installed in a parallel connection in the second approach. The two concepts were registered at the German Patent and Trade Mark Office for patents in 2015. An experimental multi-frequency generator was built and used for testing of several new ideas, such as transmitting the data using several carrier frequencies at the same time, transmitting the data with different wave forms (sine, sawtooth, triangle and rectangle), or transmitting the data using the chirp modulation. The innovative design of the experimental multi-frequency generator was registered at the German Patent and Trade Mark Office for patents in 2016.
At the receiver end, two different methods for processing and analyzing the received multi-frequency signals using the Wavelet and Fourier analysis were drafted and tested. A novel concept for the use of a multi-sensor receiver was developed and successfully tested. The use of a multi-sensor receiver could strongly improve the detection of the received signals.:Table of Contents
Declaration ii
Abstract iii
Acknowledgements v
Table of Contents vi
List of Abbreviations x
List of Symbols xii
CHAPTER 1 Introduction 1
CHAPTER 2 Modern Drilling Technology and Low Data Transmission Rate as a Limitation 5
2.1 Introduction to the modern drilling technology 5
2.1.1 Directional drilling technology 5
2.1.2 Steering technology 6
2.1.3 Measuring technology 8
2.1.4 Technology of data transmission in boreholes 9
2.2 Low data transmission rate as a problem with respect to the whole drilling process 13
CHAPTER 3 Fundamentals of Communication Technology 16
3.1 Modulation techniques for data transmission in baseband 16
3.2 Modulation techniques for data transmission in passband 17
3.3 Multiple frequency and chirp spread spectrum modulation techniques 19
3.4 Digital signal processing 21
3.4.1 Fourier transformation 21
3.4.2 Continuous wavelet transformation 23
3.4.3 Filtering 24
CHAPTER 4 State of the Art for Mud Pulse Telemetry Systems 26
4.1 Historical development of mud pulse telemetry including latest improvements applied for increasing its data transmission rate 26
4.2 Available types of mud pulse telemetry devices 30
4.2.1 Negative pulser 31
4.2.2 Positive pulser 32
4.2.3 Mud siren 32
4.2.4 Oscillating shear valve 33
4.3 Limitations of data transmission via mud pulse telemetry 34
4.3.1 Effect of noise sources in the mud channel on the transmission signal 34
4.3.2 Effect of attenuation in the mud channel on the transmission signal 36
4.3.3 Effect of reflections and their interference with the main transmission signal 37
4.3.4 Pass and stop bands 38
4.4.5 Minimum transmission time slot 38
CHAPTER 5 Novel Concepts and Tools for Increased Data Transmission Rates of Mud Pulse Telemetry 40
5.1 Transmitter end 41
5.1.1 Hybrid mud pulse telemetry (HMPT) 41
5.1.2 Multi-frequency generator 43
5.2 Receiver end 45
5.2.1 Investigation of the Wavelet analysis suitability for multi-frequency signal detection 45
5.2.2 Flexible placement of multi-sensor receiver 46
CHAPTER 6 Laboratory Test Facility and Used Hard and Soft Tools 49
6.1 Laboratory test facility for hydraulic data transmission in boreholes 49
6.2 Experimental prototypes of the pressure pulsers and mud siren 53
6.3 3D numerical simulation model for the test facility and mud siren 55
6.4 MATLAB software 58
CHAPTER 7 Hybrid Mud Pulse Telemetry (HMPT) System 59
7.1 Combination of mud siren and negative pressure pulser 60
7.2 Combination of mud siren and positive pressure pulser 63
7.3 Evaluating the laboratory investigations of the hybrid mud pulse telemetry (HMPT) system 66
CHAPTER 8 Mathematical and Numerical Investigation of the Concept of the Multi-Frequency Mud Siren 68
8.1 Preliminary considerations for the concept of the multi-frequency mud siren 69
8.2 Mathematical model investigation of different approaches for the multi-frequency mud siren concept 71
8.2.1 Multi-frequency mud siren with stators and rotors in a row 72
8.2.2 Multi-frequency mud siren with parallel connection of stators and rotors 74
8.3 Numerical model investigation of multi-frequency mud siren with two sets of stator/rotor in a row 77
8.3.1 Numerical simulations for data transmission with a multi-frequency mud siren using two carrier frequencies 79
8.3.2 Evaluation of the simulation results 81
8.3.3 Increasing the transmission reach of the mud siren for deep drilling operations 83
CHAPTER 9 Laboratory Investigations of Multi-Carrier Hydraulic Data Transmission Using an Experimental Multi-Frequency Generator 85
9.1 Laboratory multi-carrier frequency transmission tests 87
9.2 Investigation of the Wavelet analysis suitability for the detection of multi-frequency signal transmitted in boreholes 95
9.3 Initial investigations of hydraulic data transmission using chirp modulation and different pressure wave forms 100
9.3.1 Data transmission using chirp modulation (Chirp Spread Spectrum, CSS) 100
9.3.2 Data transmission using different wave forms 101
CHAPTER 10 Investigation of the Use of a Multi-Sensor Receiver for Improving the Hydraulic Data Transmission in Boreholes 104
10.1 Numerical model investigation of the use of a multi-sensor receiver 104
10.1.1 Data transmission using single-input and multiple-output (SIMO) 104
10.1.2 Data transmission using multiple-input and multiple-output (MIMO) 107
10.2 Laboratory investigations of the use of a multi-sensor receiver 108
10.3 Evaluating the use of a multi-sensor receiver for improving the hydraulic data transmission in boreholes 112
CHAPTER 11 Conclusion and Outlook 116
11.1 Conclusion 116
11.2 Outlook 120
References 122
List of Figures 129
List of Tables 136
List of Publications 137
List of Patents 138
Appendix- Chapter 7 139
Appendix- Chapter 8 141
Appendix- Chapter 9 142
Appendix- Chapter 10 146
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