DRILLING FLUID ADDITIVE; AN OVERVIEW, HISTORY OF LOCAL CONTENT DRILLING FLUID ADDITIVE CONSIDERING GUM ARABIC
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.
CHAPTER TWO
2.0 LITERATURE REVIEW
Petroleum drilling is the primordial step in the success of oilfield exploration. This success is based, on the important details derived from geological drilled formations and, on the other hand, on the good drill-in reservoir conditions. Thus, the paramount drilling objectives are to reach the target safely in the shortest possible time and at lowest possible cost, with required additional sampling and evaluation constraints dictated by the particular application. Drilling the wellbore is the first and the most expensive step in the oil and gas industry. Expenditures for drilling represent 25% of the total oilfield exploration cost and are concentrated mostly in exploration and development of well drilling. In the 90s, drilling operations represented about 10.9 billions, compared with 45.2billions (API, 1991), the total cost of US petroleum industry exploration and production.
Drilling fluids, which represent till one fifth (15 to 18%) of the total cost of well petroleum drilling, must generally comply with three important requirement: they should be, i) easy to use, ii) not too expensive and iii) environmentally friendly. The complex drilling fluid play a several functions simultaneously. They are intended to clean the well, hold the cuttings in suspension, prevent caving, ensure the tightness of the well wall, flood diesel oil or water and form and form an impermeable cake near the wellbore area. Moreover, they also have to cool and lubricate the tool, transfer the hydraulic power and carry information about the nature of the drilled formation by raising the cuttings from the bottom to the surface. Figure 1 shows a simple diagram of a rotary rig.
Drilling fluid went through major technological evolution, since the first operations performed in the US, using a simple mixture of water and clays, to complex mixtures of various specific organic and inorganic products used nowadays. These products improve fluid rheological properties and filtration capability, allowing to penetrate heterogeneous geological formations under the best conditions.In fact, borehole stability remains the main problem during drilling and the selection of drilling fluid type and composition was at the origin of successful drilling. Numerous studies have analyzed shale problems and several methods have been proposed to improve fluid performance for clay swelling inhibitions and to evaluate the scattered results already published in the literature. The majority of procedures recommend to compare initial and final sizes (or weights) of cuttings for inhibition estimation after fluid contact.
In drilling fluid technologies, two main tendencies are currently developed in parallel: i) the search for new additives increasing the performances of water-based muds (WBM) and ii) the development and introduction of new compounds into oil-based muds (OBM). Some pendent questions pendent questions will be discussed in this chapter, as well as filtration, formation damage and environmental considerations. Finally,some new solutions will be proposed by the authors.
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