Horizontal wells have become a popular alternative for the development of hydrocarbon fields around the world because of their high flow efficiency caused by a larger contact area made with the reservoir. Most of the analytical model existing in the literature on horizontal productivity either assumed that the well is infinitely conductive or the flow is uniform along the entire well length. Guo et al (2007) formulation is one the most recent and accurate models reported in the literatures for predicting production rate in horizontal well considering the frictional pressure drop along long horizontal drain hole. In this paper, an improved predictive model that takes into account the effect of other possible wellbore pressure losses on production rate variation of long horizontal well was developed. Results show that the discrepancies in the predictions of the previous models and field results were not only due to effect of friction pressure losses as opined by previous authors but may also be due to loss due to fluid accumulation experienced by the flowing fluid in a conduit. The effect is most pronounced at the early production time where initial transience at the onset of flow is experienced. The improved model was applied to the same field case study used by Guo et al and results is much more accurate and show that the error of the new model is less than 4% compared to 20% reported by Guo et al. This work provides reservoir engineers an accurate and handy tool for prediction and evaluation of horizontal wells.

Biodiesel has continued to receive enormous patronage from world energy demand as a result of its renewable nature, low toxicity, rapid degradation, robust fuel performance and low emission characteristics and its overall environmental friendliness.Hence, these data showed the optimization of temperature, catalyst concentration and type of catalyst, alcohol type and alcohol to oil molar ratio and reaction time on Avocado plant oil biodiesel yield and quality produced via alkali-catalyzed transesterification reaction. Data on the quality of the biodiesel produced by using the American Standard for Testing Materials (ASTM) procedures for biodiesel characterization with different concentrations of alcohol and catalyst under varying temperatures and reaction durations are also provided. The tested biodiesel properties are the cold flow properties (pour point and cloud point) and the critical parameters such as kinematic viscosity at 40 °C, specific gravity at 15 °C, flash point, cetane number, calorific value, iodine value, acid number and sulphated ash percentage.

Over the years, the oil industries have avoided aromatic, naphthenic, and paraffinic oils as drilling mud base fluids principally because of their detrimental environmental issues on pelagic and benthic marine ecosystems as a result of their toxicity and nonbiodegradability coupled with the possible deterioration of the oil itself and the rubber parts of the drilling equipment because the aromatic hydrocarbons present in the oil have a tendency to dissolve/damage elastomers present in rubber. Hence, possible insights into how to chemically and/or physically produce synthetic base drilling fluids whose cuttings are nontoxic, readily biodegradable, environmentally friendly, and of nonpetroleum source become imperative. In this study, enzymatic interesterification of canola oil was done with ethanol by using enzyme lipase as catalyst under optimum conditions of temperature and pressure and the physicochemical properties of the produced ester were evaluated and compared with that of diesel and a synthetic hydrocarbon base fluid (SHBF). Results show that the specific gravity, kinematic viscosity, dynamic viscosity, and surface tension of canola oil were reduced by 5.50%, 94.74%, 95.03%, and 9.38%, respectively, upon enzymatic interesterification to conform to standard requirements. Similarly, increased |mud ability to pump fluids and possibility of cold temperature environment can be achieved with the reduction in pour point and cloud point, respectively, of the produced canola oil ester. Finally, the produced ester showed no aromatic content as confirmed from its FTIR analysis which indicates its nontoxicity, biodegradability, and environmental friendliness.

A major technical and economical concern of the oil well drilling industry is the potential damage to productive formations because of excessive drilling fluid filtration and its multiplier effect on cake thickness. High fluid loss (high cake permeability) results in thick filter cake which reduces the effective diameter of the hole (tight holes) and causes various problems such as excessive torque when rotating the pipe, excessive drag when pulling it and high swab and surge pressures due to reduced hole diameter and differential pipe sticking due to increase in pipe contact.It is in this light that the potential of Zirconium (IV) oxide (Z_r O_2) nanoparticles in combating excessive filtration problem in Water Based Mud was investigated. Preliminary results show that addition of 0.50g (Z_r O_2) nanoparticle concentration brought about 19.10% reduction in fluid loss and 14.29 % reduction in cake thickness for the High Temperature/ High Pressure (HPHT) filtration test at 500psi and 250 OF. Similarly, the highest reduction of 48.31% and 38.10% in fluid loss and cake thickness respectively was achieved with addition of an optimum concentration of 2.0g of (Z_r O_2) nanoparticles for the HTHP filtration test at the same temperature and pressure.

Research on the use of plant oil or ester oil in drilling mud operation is on the increase. The is due to the less toxic and low cost advantage over the commercial synthetic base oil. Despite the attractive physicochemical properties of vegetable oil samples, it deteriorates and becomes unstable under downhole temperature and aging conditions when used directly in mud formulation. Hence, plant oil needs improvement in order to be compared to the conventional base oil. Calophyllum inophyllum oil was extracted and reacted with methano in the presence of catalyst to form biodiesel. The physicochemical properties of the commercial synthetic base oil, extracted Calophyllum inophyllum oil, and biodiesel Calophyllum inophyllum oil were measured and compared to the EN14214 and the ASTM D6751 standards. The commercial synthetic oil, Calophyllum inophyllum oil, and biodiesel Calophyllum inophyllum oil had a flash point of 101 ± 0.1, 164 ± 0.1, and 146 ± 0.1 °C respectively; density of 108, 172, and 152 (kgm3) respectively; viscosity index of 192, 163, and 282 respectively; acid value of 0.953, 24.24, and 1.0 respectively, and oil yield of NA, 71, and 62 respectively. The result showed that the biodiesel can also serve as alternative to commercial synthetic base oil due to their comparable property to the commercial base oil. The biodiesel Calophullum inophyllum oil is a potential base oil for drilling mud formulation.