Numerical simulation of individual wells in a field simulation model

Conventional numerical simulation of hydrocarbon reservoirs is inadequate for the prediction of bottom-hole pressures at production wells. This problem can be overcome by using a special mathematical model which combines individual well simulation with reservoir simulation. Severe computational instability is commonly encountered in the radial models due to the relatively small grid-blocks and high fluid velocities in the vicinity of the well bore. This instability is found to be more pronounced during depletion of the reservoir when the pressure near the well bore is below bubble-point pressure. A new technique is introduced here for saturation calculations in the critical region near the well. This technique is found to be stable for computing saturations in the small inner elements of the radial grid. Stability is maintained even for the simulation of reservoir behavior within a few inches of the producing sand face. The mathematical model developed in this study was used to predict performance of a hypothetical oil field, and these predictions were com- , pared to the performance predicted by an areal model. It is suggested that this type of model be used for reservoirs where pressure drawdown at producing wells is large, and bottom-hole pressure is less than bubble-point pressure --Abstract, pages ii-iii

Numerical simulation of one-dimensional three-phase fluid flow in a stratified petroleum reservoir with no cross-flow

A numerical model for linear, three-phase fluid flow in a stratified petroleum reservoir has been developed for the purpose of studying water-flooding performance characteristics. Gravity forces, capillary pressure and cross-flow were neglected, but the fluids were considered compressible and evaluations of dissolved gas concentrations have been accounted for. The model was used in evaluating the performance of a water flood project for a hypothetical reservoir which contained the three phases of oil, gas, and water. The results were then compared with those obtained using the Dykstra-Parsons technique. The model produces results which were found to be similar to those obtained by the Dykstra-Parsons method for the displacement of oil by water with no gas present, but poor agreement resulted when free gas saturations were formed. The results obtained using the numerical model are considered to be more realistic than those obtained by the Dykstra-Parsons method in depleted oil sands with a substantial gas saturation since the Dykstra-Parsons model was built on the assumption that only one phase flows at a point and water displace oil in a piston-like manner. When a free gas saturation is formed at the production well, the oil mobility is reduced substantially resulting in a lower oil recovery at water breakthrough than can be predicted by the Dykstra-Parsons technique --Abstract, Page ii

The Effect of Clearance on the Performance of Machine Husking Rubber Rolls for Two

تاثير الخلوص  بين الاسطوانات لنوع الماكنة Yanmar rubber roll- ST  50 على نوعية تقشير الرز ونسبة التكسر لتقييم  صنفين من الرز تارم هاشمي وديلماني والخلوص بين الاسطوانات لمكائن التقشير تحت ثلاث مستويات مختلفة 0.4,0.6 و 0.8 ملم. باستخدام تصميم التجربة CRD  وبثلاث مكررات اظهرت النتائج تفوق صنف الرز تارم هاشمي معنويا على صنف الرز ديلماني في جميع الصفات المدروسة. كانت هناك علاقة ايجابية بين زيادة الخلوص على نسبة الحبة الكاملة والرز الخام وعلاقة سلبية مع زيادة نسبة الحبوب المتشققة والتكسر وكفاءة التقشير .The effect of clearance between cylinders of  machine husking rubber rolls (type Yanmar rubber roll – ST 50) on rice husk quality and breakage percentage was evaluated for two cultivars of rice. Tarm Hashemi (TH) and Daillman (DM) and clearance between cylinders of machine husking rubber at three different levels of 0.4, 0.6 and 0.8mm.The experiment was done in factorial experiment under complete randomized design (CRD) with three replications the results indicate  that the TH cultivar is significantly better than the D M in all studied traits. There was a negative relationship between increased clearance with head rice percentage and brown rice percentage in addition to the positive relationship between the increased percentage of cracked grain ,broken rice percentage and husking efficiency

Corrosion Behavior of Diffusion Bonding Joints of (OFHC) Copper with Stainless Steel 304L in 3.5% NaCl

The present work deals with direct diffusion bonding welding without interlayer of austenitic stainless steel type AISI 304L with Oxygen Free High Conductivity pure copper (OFHC) in vacuum atmosphere (1.5 *10-5 mbr.). The optimum bonding conditions are temperature of 650 ◦C, duration time of 45 min. and the applied stress of 30 MPa, in order to secure a tight contact between the mating surfaces. The corrosion behavior of diffusion bonding joints in 3.5% Nacl is studied to evaluate the corrosion resistance of welding joints by using Potentiodynamic method. The observed microstructure of corroded specimen of optimum diffusion bonding joint shows that the corrosion current density has low value as compared with base materials used. During polarization, galvanic coupling is observed between two materials used. At passivity region, inverse polarity is occurred at 450mV. Therefore, passive stainless steel 304 L behaves as cathode respective to pure copper, the corrosion behavior of the diffusion bonding joint was mostly by copper side. The corrosion results indicate the presence of galvanic effect. The corrosion current density of copper, stainless steel 304L and bond joints condition were (3.66 µA/cm2, 1.62 µA/cm2 and 1.85µA/cm2) respectively. A SEM examination of corroded diffusion bonding joint indicates that the galvanic corrosion happened on copper side. The corrosion rate of bonding joint conditions was 0.85 mpy, which is less than 1%. This means that corrosion resistance of bond joint is more than excellent

Waqf, its substitution (istibdal), and selected resolutions of Islamic Fiqh Academy India : a maqasid al-shari'ah perspective

Waqf is a charity in which corpus is maintained and the usufruct is given to the benefisiaries. The continuity of the usufruct depends on the maintenance and management of the corpus. One of the modes used both in classical and modern times to mantain waqf-properties is substitution of one waqf-property with another known as istibdal. This paper reads into istibdal, selected resolutions of Fiqh Academy India and scrutinizes them under the shari'ah objectives of waqf and tabaeeu at ( donation ). The finding shows that modes of istibdal permitted by Islamic law realize the shari'ah objectives of waqf concomitantly. Modes which were not permitted oppose the objectives of the shari'ah. This work is a potential guide for institutions and committees involved with the development of waqf-properties using innovative financing modes

Violations of basic rights of prisoners in conventional and Islamic law: theory and practice

In prisons, the convicted are most often unattended by the authority and therefore they become victim to abuses and maltreatment. Their basic rights as humans are being violated in most of the prisons. Although there have been a lot of laws and regulations upholding the rights of prisoners prevalent in the international community, it seems ineffective in protecting their rights in real life. This paper examines the problems of the prisoners in general and discloses the issue of human rights violation of prisoners. The paper particularly exposes problems in the prisons such as sexual abuse, mental and physical torturing, illegal enforcement of prison labour, overcrowding, poor education and health care initiations. With approaching the issues of the prisoners from a human rights perspective, the paper also explores the issues from an Islamic law viewpoint and attempts to provide a conceptual frame work of solutions. A critical and descriptive analytical approach is employed in this study

Topp-Leone Weibull-Lomax distribution: Properties, Regression Model and Applications

In this paper, a new four parameter lifetime distribution called the Topp Leone Weibull-Lomax distribution is introduced. Some mathematical properties of the new distribution are studied including the quantile function, ordinary and incomplete moments, probability weighted moment, conditional moments, order statistics, stocastic ordering and stress strength reliability parameter. The regression model and the residual analysis for the new model are also investigated. The model parameters are estimated by using the maximum likelihood criterion and the behavior of these estimates are examined by conducting a simulation study. We prove empirically the importance and flexibility of the new distribution in modeling four data sets

HIV Modes of Transmission in Sudan in 2014

Background: In Sudan, where studies on HIV dynamics are few, model projections provide an additional source of information for policy-makers to identify data collection priorities and develop prevention programs. In this study, we aimed to estimate the distribution of new HIV infections by mode of exposure and to identify populations who are disproportionately contributing to the total number of new infections in Sudan. Methods: We applied the modes of transmission (MoT) mathematical model in Sudan to estimate the distribution of new HIV infections among the 15-49 age group for 2014, based on the main routes of exposure to HIV. Data for the MoT model were collected through a systematic review of peer-reviewed articles, grey literature, interviews with key participants and focus groups. We used the MoT uncertainty module to represent uncertainty in model projections and created one general model for the whole nation and 5 sub-models for each region (Northern, Central, Eastern, Kurdufan, and Khartoum regions). We also examined how different service coverages could change HIV incidence rates and distributions in Sudan.Results: The model estimated that about 6000 new HIV infections occurred in Sudan in 2014 (95% CI: 4651-7432). Men who had sex with men (MSM) (30.52%), female sex workers (FSW) (16.37%), and FSW’s clients accounted (19.43%) for most of the new HIV cases. FSW accounted for the highest incidence rate in the Central, Kurdufan, and Khartoum regions; and FSW’s clients had the highest incidence rate in the Eastern and Northern regions. The annual incidence rate of HIV in the total adult population was estimated at 330 per 1 000 000 populations. The incidence rate was at its highest in the Eastern region (980 annual infections per 1 000 000 populations). Conclusion: Although the national HIV incidence rate estimate was relatively low compared to that observed in some sub-Saharan African countries with generalized epidemics, a more severe epidemic existed within certain regions and key populations. HIV burden was mostly concentrated among MSM, FSW, and FSW’s clients both nationally and regionally. Thus, the authorities should pay more attention to key populations and Eastern and Northern regions when developing prevention programs. The findings of this study can improve HIV prevention programs in Sudan

A review on the success factors of crowdfunding-based to finance small-scale infrastructure projects

Public-Private Partnership (PPP) schemes in delivering economic and social infrastructure are growing in developing countries worldwide. Various developing countries, including Indonesia, has also been preparing and developing numerous projects, ranging from larger-scale economic infrastructures that include toll roads to multifunction satellites and smaller-scale social infrastructures that include water supply, solid-waste management, and regional hospital projects. With the increasing numbers of smaller infrastructure projects proposed by the local government, attracting financers to invest in these projects is still a challenge the government faces. Financial institutions are still averse to making the appraisal and due diligence to such projects, owing to the nature of little historical evidence of private finance involvement in small-scale infrastructure finance. In some western countries, citizens have taken the initiative to forward and finance their local infrastructure development due to realizing the social, economic, and environmental benefits of civic projects for the local community. Theoretical research has shown the opportunity of utilizing crowdfunding for local urban infrastructure; however, the factors contributing to benefit from this finance method are yet to be identified. This paper seeks to answer questions on what success factors contribute to the opportunity to adapt the crowdfunding scheme to finance a smaller-scale urban infrastructure project by conducting qualitative literature review