Petroleum
Engineering
Journal
Full Paper
A REVIEW: APPLICATION OF
BIOSURFACTANT IN ESTER BASED MUD
Muhammad Razzin bin Rosilan
23rd July 2020
*Corresponding author
muhammadrazzin97@gmail.com
School of Chemical & Energy Engineering, Engineering
Faculty, UTM, 81310, Skudai, Johor, Malaysia
Graphical abstract
Abstract
This paper provides a review on application biosurfactant in ester-based
drilling fluids. A proper formulation of drilling fluid will enable to enhance
penetration rates, reduce hole problems and minimize damages of
formation and operator will able to drill into a desired geological aim at
low cost. Choosing ester-based mud (EBM) as a proper formulation drilling
fluid already common in petroleum industry. In fact, its among promising
alternatives as its environmentally friendly due to its biodegrability
attributes instead of other types of drilling fluids. Even though, EBM has
biodegradable and lubricity properties to begin with but there are several
constraints as high kinematic viscosity, low thermal stability and prone to
hydrolysis either in acidic or base condition that can lead to detrimental
impacts on the drilling fluid performances. Different type of surfactants
can be added and affect the changes in rheology properties of EBM and
also increase the performance of EBM as drilling fluid. Hence, the
application of bio-surfactant are used for environmental purpose and at
the same time can be use as additive in drilling fluids. The present review
describes the potential applications of biosurfactants in ester-based mud.
Keywords: ester-based drilling fluid, biosurfactant,
rheological properties, performance EBM
green
energy,
Abstrak
Kertas ini menyediakan kajian semula tentang aplikasi biosurfaktan
dalam cecair penggerudian berasaskan ester. Rumusan yang sesuai
untuk cecair penggerudian akan membolehkan untuk meningkatkan
kadar penembusan, pengurangan masalah telaga dan kurangkan
kerosakan kepada pembetukan telaga dan pengendali akan dapat
menggerudi ke arah tujuan geologi yang diinginkan pada kos yang
rendah. Memilih cecair peggerudian berasaskan ester sebagai satu
rumusan yang sesuai telah menjadi kebiasaan dalam industry petroleum.
Dengan itu, ia adalah salah satu daripada alternatif yang meyakinkan
daripada cecair peggerudian yang lain kerana ia mesra alam
disebabkan sifat biodegrasinya. Walaupun EBM mempunyai sifat
biodegrasi dan pelinciran sebagai sifat asli tetapi terdapat beberapa
kekangan seperti kelikatan kinematic yang tinggi, kestabilan terma yang
rendah dan terdedah kepada hidrolisis sama ada dalam keadaan yang
berasid ataupun asas yang bole membawa kepada kesan buruk
kepada prestasi cecair penggerudian. Jenis surfaktan yang berbeza
boleh ditambah dan memberi kesan dalam sifat reologi EBM dan juga
boleh meningkatkan prestasi EBM. Oleh itu, aplikasi biosurfaktan digunkan
untuk tujuan alam sekitar dan pada masa yang sama, ia boleh
digunakan sebagai bahan tambahan dalam cecair peggerudian. Ulusan
ini menerangkan tentang potensi aplikasi biosurfaktan dalam cecair
penggerudian berasaskan ester.
85:1 (2020) 1–5 | www.jurnalteknologi.utm.my | eISSN 2180–3722 |
2
Azizul, Elmi & Muhammad Zaim / Jurnal Teknologi (Sciences & Engineering) 85:1 (2020) 1–5
Kata kunci: cecair penggerudian beasaskan ester, biosurfaktan, tenaga
hijau, sidat reologi, prestasi EBM
© 2020 Penerbit UTM Press. All rights reserved
1.0 INTRODUCTION
The ever-increasing demand for oil and gas is
pushing the global discovery and exploitation of new
resources in unexplored areas and deeper
formations. Drilling fluids also known as drilling muds
are hydraulic fluids used in the drilling industry for
maintaining hydrostatic pressure, cooling the drill bit,
providing wellbore stability and hanging the
formation cuttings. Common and frequent instances
of spills and blowouts of hydrocarbons are common
accidental situations experienced during drill
operations. Such incidents can be managed fairly
effectively by shutting down in the well with the aid
of the blowout preventers and by adjusting the
drilling fluid's physical properties. Recent progress in
deep water exploration has exposed complex
geological and environmental conditions.
Water Based Muds (WBM) which are widely used in
the current scenario are found to be highly
unsuitable for shale formations and deep-water
drilling. Water based muds are cheap and can be
formulated with easily available ingredients. When it
comes to drilling through shale formations, waterbased muds cannot be used due to very high
filtration loss. Shale formations are fine grained
sedimentary rocks made of clay minerals, calcite
and quartz. These rocks show high fissility and are
mainly composed of silt sized particles of clay. Often,
wellbore instability issues are encountered in these
formations which is due to the dispersion of the clay
into ultra-fine colloidal particles and this has a direct
impact on the drilling fluid properties. (Mohamed
Khodja, 2010)
Oil base muds (OBM) are highly effective due to
their low fluid loss and high temperature and pressure
tolerance. OBMs rules the industry for a long time until
the environmental problem caused by their disposal
was realized. Abidance by the Environmental
Protection Agency (EPA) and cost has been a major
concern which sojourns the usage of oil-based muds
(Mohammed Mokhtar Said, 2018). Low aromatic
mineral oils as well as synthetic oils have been
replacing the highly aromatic oils (e.g. diesel) in the
oil and gas industry. However, as environmental
legislation become more stringent, even the newer
and less polluting mineral and synthetic oils in vogue
now may be pronounced unsuitable because of
their
non-biodegradability.
This
led
to
the
breakthrough in the field of drilling fluids research
when researchers began to study the use of different
materials which could abide by the EPA standards
but also possess the excellent physical properties of
OBMs during the 1990s.
Therefore, ester-based drilling fluids (EBDF) is being
used to overcome this trouble. EBDF have
biodegradability, bio-accumulation, minimal toxicity
and superior lubricity attributes to become
alternatives for oil-based mud and water-based mud
(Ikodiya Orji, 2018). This type of drilling fluids created
to lessen the limitation of drilling fluids such as
environmental issues, toxicological and associated
health aspects due to oil-based mud. Using biogradable substance as base for drilling fluid is better
instead of using oil such as diesel and mineral oil. Thus,
ester fluid provides similar shale stabilization and
superior lubricity to mineral oil-based mud, and yet
also satisfies environmental parameters (Prasad,
2014).
Many companies using ester-based drilling fluids as
alternative drilling fluids instead of oil-based mud and
water-based mud due to its biodegradability and
lubricity property. Hence, high biodegradability and
relatively low toxicity have long made esters
universally recognized as the best base fluids for
synthetic-based muds in regards to environmental
performance. Despite of the characteristics,
hydrolysis of esters can be occurred when water is
added to ester in the presence of an acidic or basic
environment. Hydrolysis is triggered by higher
temperature but would also occur at normal room
temperature at lower rates. This also increases the
viscosity of the material. Hence, very high viscosity is
also not desirable since it will cause high equivalent
circulating density (ECD).(Prasad, 2014)
Hence, different kinds of surfactant were added to
ester-based mud and to maintain the properties of
ester-based mud to lease the problem contained in
EBM.. Biosurfactant have been introduced due to
their versatility and proven efficiency such as such as
emulsifying/demulsifying
agents,
anticorrosive,
biocides
for
sulfate-reducing
bacteria,
fuel
formulation, extraction of bitumen from tar sands,
and
many
other
innovative
applications.
Biosurfactants are often presented as valuable
versatile tools (Darne G. De Almeida, 2016). The main
purpose of this paper is to review on the application
of bio-surfactant in ester-based mud.
3
Azizul, Elmi & Muhammad Zaim / Jurnal Teknologi (Sciences & Engineering) 85:1 (2020) 1–5
2.0 METHODOLOGY
2.1 Synthesis of ester
The research and development of EBDF mainly
focus on the synthesis of ester from fatty acids of
vegetable oils. Esterification or transesterification is
used to modify the chemical structure of vegetable
oil (Songtham Photaworn, 2017). Vegetable oils are
eco-friendly, cheap and readily available potential
alternative to conventional mineral oils as based
fluids (Aliyu A. Sulaimon, 2017). From the
understanding, viscosity of vegetable oils is about 4
or 5 higher than diesel oil and make them unsuitable
as base fluid for mud formulation (Prof. Adewale
Dosunmu & Nigeria, 2010).
Hence, esterification and transesterification has
been applied to overcome such problems such as
high viscosity of vegetable oils and become popular
chemical process of reducing viscosity by reacting
vegetable oil with alcohol in the presence of catalyst.
Moreover, the purpose of acid esterification is to
reduce the free fatty acids (FFA) content while the
purpose of trans-esterification was to convert the
vegetable oil to methyl ester so that can be used as
base fluid for drilling mud. At table 1, there are
different types of ester are produced from these
methods because each of ester can give different
result in various properties of drilling mud.
stipulated “RP 13B-1 Recommended Practice for
Standard Practice for Field Testing Water-Based
Drilling Fluids, 2009” as a guide for laboratory works in
formulate the drilling fluids. Moreover, other drilling
fluids samples will be prepared in order to measure
the change in properties such as density, plastic
viscosity, gel strength and filtration loss as compared
to the base case and there are also studies compare
the base case with commercial drilling fluids. Hence,
there are different kinds formulation of drilling fluids
with addition of several surfactants in order to
contain the desire performance.
Figure 1 and 2 show that different sample of
formulation EBM with different oil water ratio (OWR).In
this study, they choose 80/20 as the best candidate
and continue to compared with other type of drilling
fluids. Figure 3 show the formulation of Palm Fatty
Acid Methyl Ester (PFAME) and later to be compared
with commercial drilling fluid (Escaid-110).
Figure 1 & 2: Formulation of EBM and other drilling fluid to be
compared (Arina Sauki, 2015)
Table 1: List of synthesis of ester
Figure 3: Formulation of PFAME (Mohammed Mokhtar Said,
2018)
2.2 Drilling fluids preparation
Drilling fluids formulation is important in every drilling
operation because it’s can impact the performance
of drilling fluids. Most of studies used the standard
4
Azizul, Elmi & Muhammad Zaim / Jurnal Teknologi (Sciences & Engineering) 85:1 (2020) 1–5
2.3 Measrument of rheological properties of mud
Rheology refers to the action of deformation and
flow of all kinds of matter. Some rheological
measurements on fluids, such as viscosity, gel
strength, yield point and so on, help to determine
how this fluid can flow under a range of different
conditions. This knowledge is essential for the design
of the circulation systems required for the
achievement of certain desired objectives in drilling
operations (Radzlan, 2013). The common rheological
properties that been measured in various studies are
density, plastic viscosity, yield point, gel strength, and
filtration loss.
Table 2: The rheological properties and its purpose
Figure 4: API specififications for rheology properties at 300oF
(Aliyu A. Sulaimon, 2017)
Table 3: Rheology properties of PME based mud (Aliyu A.
Sulaimon, 2017)
Rheology
properties
Plastic
viscosity
(PV), cP
Yield
point
(YP),
lb/100 ft2
10' sec
gel
strength,
lb/100ft2
10″ gel
strength,
lb/100 ft2
Electrical
stability
(ES), volts
HPHT
filtration
loss, ml
BHR
T8
AHR
Sarapar147
BHR
AHR
20
36
13
14
5
8
7
8
8
11
3
4
11
12
4
6
1624
1355
608
528
-
5.4
-
4.5
Figure 5 : Effect of addition Thinner solvent (Aliyu A.
Sulaimon, 2017)
3.0 RESULTS AND DISCUSSION
3.1 Rheology properties and performance of EBMs
Based on (Aliyu A. Sulaimon, 2017), they using palm methyl
ester (PME) as base fluid through synthesis of ester from
crude palm oil using estrification and transesterification
process to reduce viscosity. In their study, the mud weight
used is 12.5 ppg and used ratio 85:15 as water oil ratio(OWR)
for formulation drilling fluids. They find that the different
before hot rolling (BHR) and after hot rolling (AHR) are
significant. Moreover, at table 6, PME mud sample T8 with
addition of thinner solvent which is toluene reached the API
requirement for PV, GS, ES but not for YP, filtrate loss, and
mud cake thickness while Sarapar147 reached the target
values by API specifications.
Azizul, Elmi & Muhammad Zaim / Jurnal Teknologi (Sciences & Engineering) 85:1 (2020) 1–5
5
Next, palm-based ethylhexyl ester as base oil for
EBM. Using same process as before which is
transesterification by using palm oil methyl ester react
with 2-ethylhexanol and sodium methaxide as
catalyst. F2 sample gave 11.6 lb/gal as mud weight
and used 80:20 as OWR for formulation mud. Table 7
shows that F2 sample gave the best rheology
properties because its closed to API range while the
present of Versagel additive in mud make F4 sample
showed the worst rheology properties but its showed
the best in HPHT filtration test because the additive
excellent in improving fluid loss property in drilling
fluids.(Nor Saiful Hafiz Abdul Habib, 2014)
Table 4: Rheology properties for samples and API standard
(Nor Saiful Hafiz Abdul Habib, 2014)
Rheology properties
Plastic viscosity (PV),
cP
Yield point (YP), lb/100
ft2
10' sec gel strength,
lb/100ft2
10″ gel strength, lb/100
ft2
Electrical stability (ES),
volts
HPHT filtration loss, ml
F2
F4
API 13B
Specification
35
90
25-40
4.5
95
15-45
7
25
8-20
40
36
8-30
120
715
100-400
9.8
5
<10 ml
Moreover, (LINA JASSIM, 2016) make a studied
about lauric acid methyl ester as base oil in EBM. With
2-Ethylhexanol as alcohol in trasesterification process
and sodium methaxide as catalyst produce the
lauric acid methyl ester. Formulation mud including
mud weight at 12 ppg and 85:15 as OWR gave
superior rheologcal properties as shown at table 8.
With this new formulation, electrical stability stay the
same before and after hot rolling which showed
excellent thermal stability. In fact, the filtrate was
clear without any water means no hydrolysis
occurred.
Table 5: Rheology properties for sample (LINA JASSIM,
2016)
Rheology properties
Plastic viscosity (PV), cP
Yield point (YP), lb/100 ft2
10' sec gel strength, lb/100ft2
10″ gel strength, lb/100 ft2
Electrical stability (ES), volts
HPHT filtration loss, ml
BHR
25
20
14
17
1999
-
AHR
26
21
13
19
1999
2
Thus, studies from (M.M. Dardir, 2014) make two
esteramides as base fluids for their EBM and also
make comparison between their formations of EBM
with commercial synthetic-based mud. N-(2 hydroxy
ethyl) N-(ethyl linolineate) hexanamide as MT1
samples, N,N-Bis(ethyl linolineate) hexanamide as MT2
sample and commercial synthetic-based mud as MR
sample. The samples had been aging for 16hr at
350oF, hydrostatic pressure and continues circulation
to measured thermal stability property. Table 6
illustrates that new formation of EBM samples in this
study showed superior rheological properties results
compared to commercial synthetic-based. Samples
of EBM are stable at high temperature and pressure
with continuous circulation (thermal stability).
Table 6: Rheological property of EBM samples with
commercial synthetic-based mud after 16hr aging
(M.M. Dardir, 2014)
Rheology properties
Plastic viscosity (PV), cP
Yield point (YP), lb/100 ft2
10' sec gel strength, lb/100ft2
10″ gel strength, lb/100 ft2
HPHT filtration loss, ml
MT1
73
17
11
12
7.5
MT2
45
11
10
15
5
MR
50
32
15
21
9
Based on all the studies on EBM, its shows great
rheological properties with new formulation of mud,
addition of additive and modify the parameters
either to be compared with commercial drilling fluids
or API standards.
3.2 Application bio-surfactant in drilling fluids
Petroleum industry uses substantial amounts of
petrochemical-based synthetic surfactants in its
activities as mobilizing agents to increase the
availability or recovery of hydrocarbons as well as
many other applications related to extraction,
treatment, cleaning, and transportation. However,
biosurfactants have several potential applications for
use across the oil processing chain and in the
formulations of petrochemical products such as
emulsifying/ demulsifying agents, anticorrosive,
biocides
for
sulfate-reducing
bacteria,
fuel
formulation, extraction of bitumen from tar sands,
and many other innovative applications. Due to their
versatility and proven efficiency, biosurfactants are
often presented as valuable versatile tools (Darne G.
De Almeida, 2016).
The development of high performance and
environmentally-friendly clay stabilizers is still crucial to
the drilling industry. Wellbore instability is typically
caused by chemical or mechanical changes (or
both).The drilling process may encounter serious
operational problems such that the drilling operation
might be permanently stopped before reaching the
targeted oil layers. From (Aghil Moslemizadeh, 2017),
studied about mulberry leaf extract (MLE), a
biosurfactant as clay stabilizer. Biosurfactant exhibit
an environmentally friendly characteristic which an
asset for this biosurfactant. The present study assesses
the capability of MLE to inhibit the clay hydration in
aqueous phases. Moreover, MLE considerably
improve the performance of drilling operations and
boost the oil recovery factor in an enhanced oil
recovery process due to reducing the oil-brine
interfacial tension (Mohammad Ali Ahmadi, 2014).
6
Azizul, Elmi & Muhammad Zaim / Jurnal Teknologi (Sciences & Engineering) 85:1 (2020) 1–5
Other studies using non-ionic surfactant glycyrrhizin
that was obtained as Glycyrrhiza glabra rootextract
(GGRE) as a clay swelling inhibitor and compared it
with synthetic surfactant (TX-100). The compatibility
with the drilling fluid formulation was investigated
through the rheological and fluid loss analysis.They
also found that GGRE compatible with the
commercial drilling fluids additives as they
investigated the inhibition mechanism. The inhibition
mechanism probably relies on the adsorption of
hydrophilic group through hydrogen bonding on Mt's
surfaces and ori entation of the hydrophobic group
toward the aqueous phase whereby a hydrophobic
shell could be made on Mt's surfaces. Despite having
good performance, features such as cost-effective,
biodegradability,and low toxicity are great merits for
GGRE.(Aghil Moslemizadeh, 2017).
emulsification, phase separation, solubilization,
foaming, de-emulsification, corrosion inhibition, and
viscosity reduction of heavy crude oils (Zhifeng Liu,
2017).
Main application of biosurfactant is MEOR, the
tertiary recovery of oil in which microbes or their
metabolic products are used to enhance recovered
residual oil. It usually is less-expensive when
compared to chemically enhanced oil recovery
particularly when microorganisms are used to
produce sufficient products such as polymers and
biosurfactants starting with low-cost substrates raw
materials. Biosurfactants enhances the formation of
stable water-oil emulsions and the breakdown of the
oil film in the rocks which is important for a maximizing
oil extraction ultimately extending the reservoir life
time (Robert Thomas Bachmann, 2014).
3.3 Other Application bio-surfactant
4.0 CONCLUSION
Biosurfactants are mainly produced by microbial
cultures grown on water immiscible substrates,
therefore allowing access to these hydrophobic
substrates (such as hydrocarbons) and are generally
classified into low molecular-mass molecules
(lipopeptides, glycolipids) and high molecular-mass
polymers (polymeric and particulate surfactants)(O. L.
Matvyeyeva, 2014).These molecules offer several
advantages over chemical surfactants, such as
environmental
compatibility,
low
toxicity,
biodegradability, and maintained activity under
extreme conditions of temperatures, salinity and pH
values(Rita de Cássia F. S. Silva, 2014).
Figure 6: List of application of biosurfactants relevant
to the petroleum industry.(Zhifeng Liu, 2017)
In this study, biosurfactants appear to have reached
a critical stage in their commercial exploitation; after
many years in which interest in them was at a low
level, they have now come to the top of the agenda
of many companies as a result of the sustainability
initiative and green agendas. However, the recent
advances in the applications of biosurfactant in
drilling fluids especially in EBM. The world growth
toward environmentally friendly in everything due too
much of pollutant that destroying our environment.
This work systematically reviewed the source and
properties of biosurfactant and ester based mud. This
is not only because of the biosurfactants’ excellent
characteristics, but also their environmental and
economic benefits. However, some challenges still
remain in the biosurfactant application, such as the
lower
production cost
and
application
of
biosurfactant in the drilling fluids on a large scale.
Acknowledgement
Deepest gratitude to the research project supervisor,
DR. MOHD AKHMAL BIN MUHAMAD SIDEK, author’s
family and friends for the research success.
References
[1]
[2]
Table 9 show that most of the application used in
petroleum industry related to extraction, treatment,
cleaning, and transportation. Patents filed in relation
to the petroleum industry have been mainly related
to uses linked to their properties including wetting,
[3]
[4]
A. Mclean, A. W. (2010). The Top Mud-Related Concern in
Deepwater Drilling Operations- Revisied After 10 Years.
American Association Drilling Engineers.
Adesina Fadairo, O. F. (2012). Novel Formulation of
Environmentally Friendly Oil Based Drilling Mud.
ResearchGate.
Aghil Moslemizadeh, K. S. (2017). A Biosurfactant for
Inhibiting
Clay
Hydration
in
Aqueous
Solutions:
Applications to Petroleum Industry. The Canadian Journal
of Chemical Engineering.
Aliyu A. Sulaimon, B. J. (2017). Performance enhancement
of selected vegetable oil as basefluid for drilling HPHT
7
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
Azizul, Elmi & Muhammad Zaim / Jurnal Teknologi (Sciences & Engineering) 85:1 (2020) 1–5
formation. Journal of Petroleum Science and Engineering,
49-59.
Arina Sauki, M. S. (2015). Application of Ester based Drilling
Fluid for Shale Gas Drilling. IOP Conference Series:
Materials Science and Engineering.
BALACHANDRAN, A. S. (SEPTEMBER 2012). EVALUATION OF
PALM OIL BASED FATTY ACIDS FOR SYNTHESIS OF
EMULSIFIER IN DRILLING FLUIDS. UNIVERSITY TEKNOLOGI
PETRONAS.
Choon Yoong Cheok, H. A. (20`4). Extraction and
quantification of saponins: A review. Food Research
International, 16-40.
DAEL, M. A. (June 2014). TOXICITY STUDY OF OIL-BASED
MUD AND ESTER-BASED MUD ON TERRESTRIAL LIFE.
UNIVERSITI TEKNOLOGI MALAYSIA.
Darne G. De Almeida, R. d. (2016). Biosurfactants:
Promising Molecules for Petroleum Biotechnology
Advances. Frontiers in Microbiology.
Dorota Kregiel, J. B. (2017). Saponin-Based, BiologicalActive Surfactants from. Web of Science, Chapter 6.
FRANCIS D. UDOH, J. J. (20 January 2012). FORMULATION
OF SYNTHETIC-BASED DRILLING FLUID. Global Science
Publications, 175-180.
Golemanov, K., Tcholakova, S., Denkov, N. D., Pelan, E., &
Stoyanov, S. D. (2012). Surface shear rheology of saponin
adsorption layers. Langmuir.
Golemanov, K., Tcholakova, S., Denkov, N., Pelan, E., &
Stoyanov, S. D. (2013). Remarkably high surface viscoelasticity of adsorption layers of triterpenoid saponins. Soft
Matter.
Hazlina Husin, Z. H. (20`4). Clarifying the Palm-based
Drilling Fluids Potentials. INTERNATIONAL CONFERENCE ON
GLOBAL SUSTAINABILITY AND CHEMICAL ENGINEERING.
Ikodiya Orji, M. U.-E. (2018). Synthesis of ester base fluids for
drilling mud formulation using different catalyst.
International Journal of ChemTech Research, 373-382.
JALIL, M. A. (JUNE 2017). APPLICATION OF BIOLUBRICANT
IN WATER BASED DRILLING FLUID. UNIVERSITI TEKNOLOGI
MALAYSIA.
Jassim, L. I. (2015). Development of Ester-Based Drilling
Fluids for Wellbore Enhancement. Universiti Putra Malaysia.
Kulbhushan Samal, C. D. (2017). Eco-friendly biosurfactant
saponin for the solubilization of cationic and anionic dyes
in aqueous system. Dyes and Pigments.
LINA JASSIM1, R. Y. (2016). Synthesis and Optimization of 2Ethylhexyl Ester as Base Oil for Drilling Fluid Formulation.
Chemical Engineering Communications.
Luis Alberto Alcázar-Vara, I. R.-M. (2018). Drilling Fluids for
Deepwater Fields: An Overview. Web of Science, Chapter
4.
M.M. Dardir, S. I. (2014). Preparation and evaluation of
some esteramides. Egyptian Journal of Petroleum.
Mai Anugrahwatia, T. P. (2016). Extraction of Ethanolic
Extract of Red Betel Leaves and Its Cytotoxicity Test on
HeLa Cells. 4th International Conference on Process
Engineering and Advanced Materials.
Mohamed Khodja, M. K.-S. (2010). Drilling Fluid Technology:
Performances
and
Environmental
Considerations.
ResearchGate.
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]
[37]
[38]
[39]
Mohammad Ali Ahmadi, Y. A. (2014). Preliminary
evaluation of mulberry leaf-derived surfactant on
interfacial tension in an oil-aqueous system: EOR
application. Fuel.
Mohammed Mokhtar Said, A.-A. H.-S. (2018). The use of
palm oil fatty acid methyl ester as a base fluid for a flat
rheology. Journal of Petroleum Science and Engineering,
969-983.
Mohd Kassim Salleh, S. v. (2011). Palm Oil Derived Esters –
An Environmentally Safe Drilling Fluid .
Nor Saiful Hafiz Abdul Habib, R. Y.-Y. (2014).
Transesterification Reaction for Synthesis of Palm-based
Ethylhexyl Ester and Formulation as Base OIl for Synthetic
Drilling Fluid. Journal of Oleo Science.
O. L. Matvyeyeva, . О. (2014). Microbial Biosurfactants
Role in Oil Products Biodegradation. Science and
Education Publishing.
Omotioma M.1, M. G. (2014). EFFECT OF PLANT EXTRACT
OF AFRICAN STAR APPLE ON THE RHEOLOGICAL.
International
Journal
of
Environmental
Science,
Management and Engineering Research.
Prasad, R. V. (2014). CHARACTERIZATION OF A NEW
VEGETABLE. the Faculty of the Department of Civil and
Environmental Engineering.
Prof. Adewale Dosunmu, S. O., & Nigeria, U. o. (2010).
Development of Environmentally Friendly Oil Based Mud
Using Palm-OIl and Groundnout-Oil. Society of Petroleum
Engineers.
R.A.M. Amin, D. C. (2010). Joint Development of an
Environmentally Acceptable Ester-Based Drilling Fluid.
Society of Petroleum Engineers.
Radzlan, R. B. (2013). The Effect of Lime and Primary
Emulsifier on Rheological Behaviour of Palm Fatty Acid
Distillate (PFAD)-based Drilling Fluid.
Rita de Cássia F. S. Silva, D. G. (2014). Applications of
Biosurfactants in the Petroleum Industry and the
Remediation of Oil Spills. International Journal of
Molecular Sciences.
Roy, A. (2017). A Review on the Biosurfactants: Properties,
Types and its Applications. Journal of Fundamentals of
Renewable Energy and Applications.
Ryan Van Zanten (Halliburton Co.), J. J. (2012). Improved
Stability of Invert Emulsion Fluids.
S.Z. Razali, R. Y. (2018). Review of biodegradable
synthetic-based drilling fluid: Progression,. Renewable and
Sustainable Energy Reviews, 171-186.
Songtham Photaworn, C. T. (2017). Process development
of two-step esterification plus catalyst solution recycling
on waste vegetable oil possessing high free fatty acid.
Chemical
Engineering
and
Processing:
Process
Intensification.
Stanimirova, K. M. (2011). Surface shear rheology of
saponin adsorption layers. Langmuir.
[40] Zhifeng Liu, Z. L. (2017). Recent advances in the
environmental applications of biosurfactant
saponins: A review. Journal of Environmental
Chemical Engineering.