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The development of an oil-based mud from palm oil and ground-nut oil was carried out in this work. It also compares the eco-toxicological properties of conventional base oil of diesel and vegetable oils derived from palm oil and groundnut oil. A drilling mud was formulated with both palm oil and groundnut oil and standard additives were added. Complete mud check was conducted on the mud in order to determine the rheological properties. Toxicity of diesel, palm oil and groundnut oil were compared by exposing corns planted on humus soil beds prepared with palm. Also, groundnut oil-based mud with an oil/water ratio of 90/10 was formulated successfully. When the humus beds planted with corn were exposed to diesel, palm oil and groundnut oil, the corn exposed to diesel lost its greenness and died while that exposed to palm oil and groundnut oil retain its greenness. Palm oil-based mud having 90/10 oil/water ratio and groundnut oil-based mud exhibited a 20% and 12% average rate of growth without losing all its greenness. Palm oil based mud formulated with different oil/water ratios congealed during the course of formulation. They exhibited high viscosity and progressive gel characteristics. In conclusion, oil based mud developed using Palm oil and groundnut oil should be encouraged since its highly biodegradable, have better eco-toxicological properties and the cost of treatment of the cuttings are lower compared to Oil-based drilling mud formulated with diesel, mineral and conventional synthetic oil. They can also be a source of income to the farmers producing the palm oil in large quantity and help in the growth of the Nigerian economy since we can supply the palm oil to oil and gas companies that need it to produce their mud for drilling operations. In addition to these benefits, the oil based mud formulated with palm oil and groundnut oil is also functionally as efficient as the ones formulated with diesel and conventional synthetic oils.

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Efficient cuttings transport and hole cleaning is a very important factor that must be considered during drilling operations. In inclined and horizontal drilling, hole cleaning is a common issue since there is high tendency for formation of cuttings bed in the hole which can lead to several complex problems. The optimization of cuttings transport depends on so many factors like hole angle, cutting size, drill string rotation, drill pipe eccentricity, bit hydraulics etc. This paper is designed to examine critical factors that affect the efficient cleaning/transport of cuttings and bit hydraulics in inclined wells with a view to understanding how to minimize drilling difficulties thereby reducing non producing time (NPT) during drilling operations. The developed model ensures proper hole cleaning in the critical hole angle (between 45° and 60°) as well as horizontal wells and determining the optimum flowrate and rate of penetration (ROP) that will ensure successful drilling. The model also helps to save time wasted when we encounter problems of high concentrations of cuttings which causes high Equivalent circulation density (ECD) that can result in lost circulation problem amongst others. Finally, the developed model is validated using field data and graphs showing how the penetration rate increases as cuttings concentration in the annulus reduces thereby optimizing drilling operations.

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This work was carried to study Guar gum as a Hydraulic Fracturing carrier fluid and also to look at how we can properly optimize the properties of the Guar gum to achieve a very efficient carrier fluid that will suspend proppant into the formation.The problems that necessitated the carrying out of this project was that over the years there has been failure in hydraulic fracturing operation due to shear degradation of Guar carrier fluid, high temperature denaturing of Guar carrier fluid and insoluble residue formation from Guar carrier fluid which may cause formation damage.These problems where studied using shear history simulator, high temperature and high pressure viscometer and also API RP39 procedure which gives the guideline for testing carrier fluid. It was established through this work that proper optimizing of the guar concentration can be used to control the shear degradation and temperature effect on the Guar carrier fluid. Also with the application of necessary additives, the Guar carried fluid can be used in a very high temperature formation.

The focus of this research was to present a data article for analyzing the cost of displacing a drilling fluid during the drilling operation. The cost of conventional Spud, KCl and Pseudo Oil base (POBM) muds used in drilling oil and gas wells are compared with that of a Reversible Invert Emulsion Mud. The cost analysis is limited to three sections for optimum and effective Comparison. To optimize drilling operations, it is important that we specify the yardstick by which drilling performance is measured. The most relevant yardstick is the cost per foot drilled. The data have shown that the prices for drilling mud systems are a function of the mud system formulation cost for that particular mud weight and maintenance per day. These costs for different mud systems and depend on the base fluid. The Reversible invert emulsion drilling fluid, eliminates the cost acquired in displacing Pseudo Oil Based mud (POBM) from the well, possible formation damage (permeability impairment) resulting from the use of viscous pill in displacing the POBM from the wellbore, and also eliminates the risk of taking a kick during mud change-over. With this reversible mud system, the costs of special fluids that are rarely applied for the well-completion purpose (cleaning of thick mud filter cake) may be reduced to the barest minimum.