CHAPTER ONE
1.0 INTRODUCTION
Drilling mud is a flowing fluid applied in rotary drilling for
achieving single or multiple tasks during the procedure, and its
typically consist of water/oil, clay, weighing compounds and few other
chemical additives (American Institute of Petroleum, 1998). It most
important physical characteristics are viscosity and water
holding/retaining properties (Crowo, 1990). The successful and cost of
the drilling process is known to depend extensively on the asset of the
drilling fluid used (Gray, et al., 1980). Drilling mud circulates in a
loop, from the building platform, where is forced down into the
formation system by entering the drill string, and pushed up to the
surface again via the drill bit. The fluid characteristics such as
density and temperature are variables that need to be regularly
monitored for the perfect drilling performance according to the
condition of the drilling well (Issham and Ahmad Kamal, 1997; Rabia,
1985).
Drilling fluids are commonly known for their gel or thixotropic
characteristics, in which they can go through a reversible
transformation from high to low viscosity status when being subjected
to shear stress force (Dolz et al., 2007). These transformations ruin
the microstructure of the but will be gradually recovered when the fluid
is in resting condition (Azar and Samuel, 2007).
Usually, the industrial capability of wells is impaired by
multifaceted interfaces between rock and fluid, which decrease
permeability to oil and gas. For that reason, drilling mud should be
continuously formulated to diminish these undesireabe effects (Hamida,
Kuru, & Pickard, 2010). Depth, pressure and mechanical/impact
resistance of the wellbore are the key parameters that determined which
type of the mud is most relevant. Inspite of their differences in
categories, that main purposes and functions remain mutual (Barnes et
al., 1998). They function to preserve hole reliability, convey the rock
cuttings, managing the pressure of the mud system along with
lubricating and cooling the drill bit (Baba Hamed and Belhachi; 2009;
Brazzel, 2009; Caenn and Chillinger, 1996; Gonzalez et al., 2011). At
the current time drilling mud are categorized by their external phase
or basic material into five major groups, which are oil based drilling
mud (OBM), Synthetic base drilling mud (SBM), Water based drilling mud
(WBM), Gas based
drilling mud (GBM) and Nano based drilling mud (Davis et al.,
1984; Van Dyke and Baker, 1998).The significant factors for
distinguishing the assets of a drilling fluid are gel strength,
viscosity(apparent and plastic viscosity), explicit weight, PH, thermal
stability and the filtration function (Caenn et al., 2011., Sondona,
1985).
Untreated colloids, basically starch and its modified types, were
used in drilling fluid industry for a long time to defeat the hazardous
effect of anhydrite and saline on drilling fluids (Civian, 2007;
Windarto et al., 2011).Managing the fermentation made by micro-organism
in drilling muds, which are composed of gums, starches and tenants
additives, is one of the most important problems in drilling mud
formation. In an effective stated drilling mud, depending on the PH,
Heat, Ventilation group of enzymes get activated which assist
microorganisms to fermentation dilemma in starch based drilling muds is
generally chanlleged by adding an antiseptic like paraformaldehyde,
which is fairly economical (Myers, 1962; Soepenberg et al., 1983). In
drilling mud composition different polymer and chemical are used for
various applications, this chemicals mostly influence the rheological
and fluid loss properties of the mud (Austin, 1983).
1.0: BACKGROUND STUDY
1.1.1 GUM ARABIC
Gum Arabic, the natural exudates from Acacia Senegal, a high
molecular weight heteropolysaccharide (hydrolysis result D-galatose
with lesser amount of 4-o-methyl-D-glucoronic acid), shows unusual
solution behavior compared to other polysaccharides of similar molecular
weight. The rheology of Arabic gum has been extensively studied. Gum
solution 30% shows higher solution viscosity and exhibit
pseudoplasticity. Some reports are available on shear thickening
behavior of Arabic gums while recently Mothe and Rao reported that the
gum shows shear thining behavior at low shear rate (1-50s). The
instrumental measurement of low viscosity fluids like Arabic gum
solutions has been a difficult task; however, with the advent of
controlled stress rheometer, it is now possible to characterize the
exact flow behavior of fluids with viscosities less than ImPaS. The
reports on the rheology of Arabic gum are contradictory and need
further investigation.
Presently, considerably attention has been given to the study of
various hydrocolloids and their combinations for thickening and texture
modification in gravies, dairy products, food drinks and pet foods
because their rheological and functional properties are complimentary.
Recent applications have proved that such blends can produce new food
formulations and ingredients. Gum Arabic is compatible with most other
gums due to its low viscosity characteristics. The structure of gum
Arabic contains proteinaceous material (2%) covalently joined with
polysaccharide moiety. It gives a smooth flow or sometimes flow or
sometimes reduces high viscosity in combination with other gums like
Xanthan, gelatin, agar, guar gum and modified starches to produce
various confections. The gum has been beneficial when a thin, pourable
consistency is desired. The synergic effects of Arabic gum have also
interested the food processing industries. The resulting rheological
properties of various gums depend on the gum concentration molecular
weight of the polysaccharides and functional groups, and the degree of
interaction between two hydrocolloids. Associations of participating
hydocolloids occur if biopolymer the interaction is favorable while
mixture of the repulsive hydrocolloids exhibits thermodynamics
incompatibility.
1.1.2 GINGER
Ginger (zingiber efficinale Rescoe) is a flowering plant in the
family zingiberaceae whose rhizome, ginger root or simply ginger, is
widely used as a spice or medicine. It is herbceous perennial which
grows annual stems about a meter tall bearing narrow green leaves and
yellow flowers. Ginger is indigenous to South China, and was spread
eventually to the spice Islands, other parts of Asia and subsequently
to West Africa and Carribean. Ginger was exported to Europe via India
in the first century AD as a result of the lucrative spice trade. India
is now the largest producer of ginger.
Other members of the family zingiberaceae include tumeric
Cardamon, and galangal. The distantly related dicots in the Gervus
Asarum are commonly called wild ginger because of their similar taste.
Mature ginger rhizomes are fibrous and nearly dry. The juice from
ginger roots is often used as a spice in Indian recipes and is a common
ingredient of Chinese,
Korean, Japanese, Vietnamese, and many South Asian Cuisines for
flavoring dishes such as seafood, meat and vegetarian dishes.
Ginger is an herb, the rhizome (underground stem) is used as a
spice and also as a medicine. It can be used fresh, dried and powdered,
or as a juice or oil.
Ginger is commonly used to treat various types of stomach
“problems”, including motion sickness, morning sickness, Colic, upset
stomach, gas diarrhea, nausea, caused by cancer treatment, nausea and
vomiting after surgery as well as loss of appetite. Other uses include
pain relief from arthritis or muscle soreness, menstrual pain, upper
respiratory tract infections, cough, and bronchitis. Ginger sometimes
used for chest pain, low back pain, stomach pain.
Some people pour the fresh juice on their skin to treat burns. The
oil made from ginger is sometimes applied to the skin to relieve pain.
In foods and beverages, ginger is used as a flavoring agent. In
manufacturing, ginger is used as for fragrance in soaps and cosmetics.
One of the chemicals in ginger is also used as an ingredient in
laxative, anti-gas, and antacid medications.
1.2 PROBLEM STATEMENT
In the past, researches have been examining the possibilities of
producing drilling fluids using strictly locally derived materials,
this is partly successful as it is discovered that Nigeria have the
necessary materials to produce Locally based drilling fluids but the
major problem encountered is that the gel strength of the drilling
fluids produced using local substitutes is too low and the fluid loss
is too high and as a result, this is not suitable for drilling
processes. Also local materials have been used in the past to produce
drilling fluids but the major problem encountered is that when tested,
the result is very low gel strength, high fluid loss and therefore not
good enough to be used. Gum Arabic is one of the locally based
materials used which is readily available in large quantity and highly
soluble in water.
1.3 AIM OF STUDY
This study is aim at formulating drilling mud using locally
derived materials i.e. a mixture of Gum Arabic, which is readily
available in commercial quantity in the northern part of Nigeria and
banana peels as a viscosifier and fluid loss additives.
1.4: OBJECTIVES OF STUDY
- To study how to improve the viscosity of gum Arabic using ginger.
- To advance and project the use of local content drilling fluid additive.
- Investigate how the viscosity of gum Arabic can be increase to
meet up to the viscosity of standard viscosifier like CMC, PACR etc.
- To determine the effect of down hole condition on the mud system such as pH, salt and ageing.
1.5 JUSTIFICATION OF THE STUDY
The design and production of drilling fluids in Nigerian oil and
gas sector over the years has been faced with the challenges of either
importing the materials to produce and or in some cases imported,
already designed and produced drilling mud. In this case, industry in
this sector adjust the properties of the drilling fluid with the aid of
the right types of additives which are also imported to suit the
formation requirements of the area to be drilled. This has not allowed
them to compete effectively with their foreign counterparts. Research
into this area is thus very necessary.
Country like India, where cheaper substitutes for production of
different goods and services are found (including the oil and gas
sector and the production of drilling fluids), using their local
materials. This has improved their economy with benefit of job
opportunities that are created with their own natural resources which
means reduction in the amount of importation. Nigeria is replete with
natural resources in various forms, thus research to find how our own
raw materials can be used or the availability of suitable substitutes
which can be develop and examined within our country for educational
and technological advancement of Nigeria.
The Petroleum Industry Bill that was proposed seeks to achieve the
‘promotion of the development of local (Nigerian) content (both
personnel and resources) in the oil industry’ as one of its major goal,
with this in view the need for the development of local additives as
substitute for foreign additive is paramount, thereby the possibility
of the use of banana peel in place of C.M.C or H.E.C due to the
availability banana Nigeria is being explored. Also this research has
ultimate direct impact on the Nigerian economy as the federal government
under the auspices of the Nigerian national petroleum corporation
(NNPC) has been encouraging the development and use of local content in
the oil and gas industry.
With large production of waste banana peels in the world at large
and Nigeria in particular, development of viscosifier from banana peels
will help reduce the environmental pollution cause by the peels, it
will also to reduce the importation of foreign additives thereby help
in trade balancing.
1.6: SCOPE
The scope of this work is focused on drilling fluid additive; an
overview, history of local content drilling fluid additive considering
gum Arabic and how to improve on it, in this study ginger was added to
Gum Arabic as a local additive. In this work water base fluid is only
considered and rheological property (viscosity, gel strength, yield
point) of the mud was carried out. The effect of salt alkalinity and
ageing on the new mud formulation (ginger and gum Arabic) was
determined.
1.7: LIMITATION
Lack of prior research study on this topic. In other word
literatures, journal and publications in relations to local content
drilling fluid additive.
A full description of the fluid by analyzing its entire properties may not be possible i.e. mud density, mud pH.
Drilling fluid may not be subjected to reservoir condition in terms of temperature and pressure.