COMPARATIVE APPROACH TO OPTIMUM SELECTION OF ARTIFICIAL LIFT SYSTEM

Artificial lifts are used around the world in approximately 85% of the wells and its overall efficiency cannot be overestimated. The specific lift method for a particular application is largely accomplished by production engineers; they apply both field / operational experience, and modern knowledge. This quality has been recognized as a defect in most engineering disciplines and have led to sub-optimal design in projects. Improper selection of artificial lifts can lead to a reduction in production and a significant increase in operating costs. Once a decision is made about the type of lift that will be installed in a well, whether or not this method is chosen optimally for the existing conditions of the well; very little can be done after installation. This paper analyzed the selection criteria for various artificial lift techniques and illustrate why the selection made is the most suitable technique to be applied in that particular well condition. For optimum decision making, the study considered the characteristics of the reservoir, their operational and design characteristics, the location of the facility and the artificial lift system economic. The economic evaluation of each case was carried out taking into account the capital and operating cost for each option

An Application of Spline and Piecewise Interpolation to Heat Transfer (Cubic Case)

An Application of Cubic spline and piecewise interpolation formula was applied to compute heat transfer across the thermocline depth of three lakes in the study area of Auchi in Edo State of Nigeria. Eight temperature values each for depths 1m to 8m were collected from the lakes. Graphs of these temperatures against the depths were plotted. Cubic spline interpolation equation was modelled. MAPLE 15 software was used to simulate the modelled equation using the values of temperatures and depths in order to obtain the unknown coefficients of the variables in the 21 new equations. Three optimal equations were found to represent the thermocline depth for the three lakes. These equations were used to obtain the thermocline gradients.....

De-emulsification of Nigerian light crude oil using heavy Akylbenzene Sulfonate and its rheological verification

This technical paper evaluates de-emulsification and rheological verification of Nigerian light crude oil emulsion viscosity using statistic model. The light crude oil which is paraffin base, of low wax content was emulsified with brine solution to obtain stable emulsion before deemulsification with heavy alkylbenzene sulfonate. The measurements of the viscosity of the emulsion before and after water separation were carried out using rotational viscometer. Model prediction coefficients of emulsion viscosity, using shear stress and concentrations relationship was established by application of statistical analysis of statistic software version (6). The graphs of observed data versus predicted, shear stress and shear rate data, measured values and predicted values were plotted respectively and 99.954% was obtained as correlation co-efficient. Also, from statistical analysis modeling, the flow behavior index of light crude oil emulsion viscosity is 0.99701, which is approximately 1, which shows the Newtonian fluid behavior

Measurement of the Best Z-Factor Correlation Using Gas Well Inflow Performance Data in Niger-Delta

Gas compressibility has a long and important history for gas industries. The use of z-factor in real gas analysis is unavoidable; hence study of the effects of different z-factor correlations against real life data was carried out. This research establishes the need and a solution for a simple, robust and flexible technique requiring the use of different z-factor correlations. The most common sources of z-factor values are experimental measurement, equations of state method and empirical correlations. Necessity arises when there is no available experimental data for the required composition, pressure and temperature conditions. Presented here is a technique to predict z-factor values using Gas Well Inflow Performance data. The three gas correlations under study are Hall and Yarborough, Dranchuk, Abu and Kassem and Dranchuk, Purvis and Robbinson. The interest of the research was to show the best Z-Factor correlation for Niger Delta. The method or approach used was to review existing models, developed a computer program to evaluate numerically the three correlations and the best correlation is shown by running a statistical absolute average error for each of the calculated gas well performance against the history inflow performance data. Based on the study analysis performed using the Niger-Delta, the Hall and Yarborough is ranked first, followed by Dranchukpurvis-Robbinson, while Dranchuk-Abu-Kaseem is recorded the last in the ranking model. Based on this study, it is recommended that the Hall and Yarborough gas deviation model is the best model for Niger Delta

GAS PROCESS SYSTEM EMPIRICAL TOOL FOR PREDICTING HYDRATE FORMATION

The rapid formation of gas hydrates, promoted by typical high pressure/ low temperature operating conditions in deep water installations, is considered one of the most difficult problems with flow assurance. Understanding the conditions for the formation of hydrates is necessary to overcome the problems associated with hydrates. Ideally, the conditions for the formation of gas hydrates are determined experimentally in the laboratory; but this data is not always available. Therefore, correlation is used to determine the conditions for gas hydrate formation. Several models have been proposed that require more complex and longer computations to predict the conditions for the formation of gas hydrate over the years. In this study, it is crucial to develop a reliable and easy-touse method for oil and gas practitioners’. The proposed correlation extends over a wide range of pressure (2000 to 25000kPa) and molecular weights (16 to 27). Consistent and accurate results of the proposed pressure range, temperature, and molecular weight are presented. Statistical error analysis is used to appraise the efficiency and accuracy of the correlation coefficient for estimating the formation of gas hydrate. This will guide designer and operator to select the optimal correlation for a particular application

Potential of Tarpon (Megalops) atlanticus for sport fisheries and ecotourism development in Nigeria

The Atlantic Tarpon, Tarpon (Megalops) atlanticus is a marine fish of high commercial importance with a special fishery in western, central and south-western Atlantic Ocean where it is a very important game fish. The species provides sport fishery especially in the western Atlantic coast of America which has generated millions of dollars in tourism, employment and boat charters. Tarpon fishery in America is highly regulated and there are strict guidelines on capture, bag limits and fishing seasons. Tarpon puts up a spectacular fight when hooked, leaping up to 2-3m above water surface and landing with a smacking splash that can be heard one kilometer away. It is the leaping powers that make tarpon a favourite to anglers. In the coastal waters of south-west Nigeria especially for the natives of the coastal communities of Ondo State, T. atlanticus is a delicacy and of high economic value. Some local fishermen and fish farmers in the area stock Tarpon in their ponds purely for recreational purposes. Some of these tarpon farms were integrated with snack bars and served as tourist centres. Visitors including individuals and educational institutions frequent the fish farm during excursions and pay a stipulated fee per person as entry permit to the farm thereby generating more revenue to the farmer. This paper highlights the importance of Tarpon as a game fish and suggests strategies for development of its culture both as food fish and for ecotourism

Impact of Talent Management Strategies on Organizational Performance in Selected Deposit Money Banks in Lagos State, Nigeria

This study critically examined the Impact of Talent Management Strategies on Organizational Performance in Selected Deposit Money Banks (DMB) in Lagos State, Nigeria. Specifically, the study sought to; (i) determine the extent succession planning relates to sustainability; (ii) ascertain to what extent human capital development impacts on innovative capabilities of employees; and, (iii) examine the degree compensation impacts on employee engagement, in selected DMBs under study. The study adopted the survey design. The population of the study was 3126 comprising management and junior staff drawn from the selected DMBs in Lagos state, Nigeria. These include First Bank of Nigeria Plc, United Bank for Africa Plc, Zenith Bank Plc, Access Bank Plc, and Ecobank Plc. The sample size of 359 was obtained from the population using Bill Godden\u27s formula at 5% error margin and 90% level of confidence. Data were collected using the questionnaire research instrument and interview guide which was designed in a 5-point Likert Scale and was manually administered to the respondents. The validity of the instrument was measured using content validity, and this was done by three management experts from both the industry and the academia

Estimation of Flow Capacity in Pipelines Based on the Intrinsic Variation of the Volumetric Properties of the Natural Gas Mixture

In this paper, the Weymouth equation was applied so as to consider the pipeline characteristics, thermodynamic and physical gas properties. From literature, volumetric parameters like the specific gravity and compressibility are mostly assumed to be constants. Since they are related to flow, pressure and temperature values; neglecting their variation during pipeline transportation may lead to significant misleading results in the computation of pipeline resistance. Considering that providing global optimal solutions to instances of considerable size can become time-consuming, thus a mathematical optimization method was applied to find the solution that will satisfy these systems. Critical property correlations (Thomas, Standing and Sulton) and Compressibility correlations (Hall-Yarborough, Danchuk-Purvis Robinson are used mathematically to generate results that will optimize the gas pipeline transportation without assuming specific gravity and compressibility factor of the gas constant. The model proposed in this study showed that specific gravity and compressibility have an effect on gas pipeline flow rate. It was observed that at very low and very high specific gravity, that the gas flow rate is reduced by more than 10% while the gas density increases. It can also be stated from the results that, compressibility is directly proportional to flow rate and inversely proportional to density

A Review on Gas Well Optimization Using Production Performance Models—A Case Study of Horizontal Well

This study considered the solution methods to determine optimal production rates and the rates of lift gas to optimize regular operational objectives. The foremost tools used in this research are offered as software platforms. Most of the optimization hitches are solved using derivative-free optimization based on a controlled well Performance Analysis, PERFORM. In line with production optimization goal to maximize ultimate recovery at minimum operating expenditure, pressure losses faced in the flow process are reduced between the wellbore and the separator. Nodal analysis is the solution technique used to enhance the flow rate in order to produce wells, categorize constraints and design corrective solution. A hypothetical case is considered and sensitivity analysis using the IPR Models for horizontal gas wells provides the effect on pressure and liquid drop out. The gas lift method is economically valuable as it produced an optimal economic water cut of 80 percent with 2 - 4 MM scf/day rate of gas injection; thus, 1800 - 2000 STB/day gas was produced

Offshore Gas Well Flow and Orifice Metering System: An Overview

This research presents a concise account of offshore surface well test from objective, organization, to practical approach and in relation to orifice metering system of natural gas; against the perspective of regulatory standards. With reference to reliability, availability, affordability and including control measures governing the design, the orifice meter sometimes called a head loss flow meter is chosen most often because of its reputation in the oil and gas industry. Alternative metering system of natural gas, including robust and cost effective innovations within the industry which addressed some key limitations of orifice meter was examined. The advanced flow computer with transducers suited for orifice measurement installations is a cost effective electronic flow real time measurement system. It has telemetry features and improved accuracy under fluctuating flow conditions based on functional differential pressure root mean squared volume calculation principles. These new developments and their capabilities have reduced the market share of the mechanical orifice chart meters. Except that Electronic flow meters has environmental limitations; thus, the proven mechanical orifice metering systems are still an effective solution for many flow measurement applications