OPTIMAL SIDETRACK TIME EVALUATION BY SEGMENTED PROXY MODEL

Sidetrack operations which involves accessing a new zone and commingling production gives rise to uncertainties and proxy models have shown to be able to incorporate uncertainties and mimic real-life scenarios to an acceptable degree of accuracy. In this paper, a time-based proxy model which inte-grates the uncertainties that emerge as a result of several reservoir parameters was developed using NPV as the objective function. A black oil simulator was used to generate the production profile and NPV computed using certain economic parameters. The Box-Behnken response surface design was used to generate a combination of variables with which the experiment was carried out. Non-linearity of the NPV which was caused by the impact of time was corrected using segmented regression and the split design was based on visual observation of the main effect plot. The segmented proxy models obtained were reasonable to an acceptable degree of accuracy in mimicking the simulation model

Enhanced Oil Recovery of Medium Crude Oil (310 Api) Using Nanoparticles and Polymer

The aim of enhanced oil recovery (EOR) is to influence the fluid-fluid properties and fluid-rock properties between the injected fluid and the residual oil phase to improve recovery efficiency. New methods of improving recoveries have been investigated since they provide lower risks, costs and uncertainty as compared to exploring for new reserves. Water enhanced with nanoparticles (nano-fluid) has recently gained research interest for enhanced oil recovery because of the possible physical and chemical properties imparted by the nanoparticles. The purpose of this research was to investigate and improve oil recovery after water flooding by nanofluid flooding. Nanoparticle used was silica nanoparticles (SiO2) suspended in deionized water at 0.05wt% concentrations. The results from the core samples show an additional oil recovery of 4.29%, 2.022% and 1.86% respectively from three (3) cores (core 2, core 5 and core 6) at nano flooding rate of 0.5cc/min. Core 7 gave a recovery of 33% during water flooding and 38.2% during nano-fluid flooding thus giving an incremental recovery of 5.2%. These results have validated the effectiveness of chemical flooding especially nanoparticles to successfully recover crude oil from reservoirs after water flooding usefulness has declined

Characterizing 90 accessions of sweetpotato in high rainfall sites of southern Nigeria

A field collection of 90 sweetpotato (lpomoea batatas) accession collected. from various sources within and outside Nigeria were characterized at the llTA High Rainfall Station in Onne, Rivers State between June and August 2006. The objective of the study was to identify their distinctive characteristics and mountain of germplasm collection for evaluation and further research. Some of the accessions were found to be similar, based on whole-plant characteristics and were divided into 8 groups named after the first succession in which such characteristics were observed. The considerable variation observed in terms o/'leaf shape, leaf size, plant type und ground cover confirmed the large genetic varialibity, present in sweetpotato. Fammers interviewed during the germplasm collection activities in Bayelsa and Rivers state indicate that ability to spread fast und suppress weeds was a major consideration when selecting a sweetpotato varieties for cultivation. This highlights the need to include fammers in the selection process which will culminate in the release of new varieties for commercial cultivation in the country

Global prevalence, treatment, and prevention of hepatitis B virus infection in 2016: a modelling study.

Background The 69th World Health Assembly approved the Global Health Sector Strategy to eliminate viral hepatitis by 2030. Although no virological cure exists for hepatitis B virus (HBV) infection, existing therapies to control viral replication and prophylaxis to minimise mother-to-child transmission make elimination of HBV feasible. We aimed to estimate the national, regional, and global prevalence of HBsAg in the general population and in the population aged 5 years in 2016, as well as coverage of prophylaxis, diagnosis, and treatment. Methods In this modelling study, we used a Delphi process that included a literature review in PubMed and Embase, followed by interviews with experts, to quantify the historical epidemiology of HBV infection. We then used a dynamic HBV transmission and progression model to estimate the country-level and regional-level prevalence of HBsAg in 2016 and the effect of prophylaxis and treatment on disease burden. Findings We developed models for 120 countries, 78 of which were populated with data approved by experts. Using these models, we estimated that the global prevalence of HBsAg in 2016 was 3\ub79% (95% uncertainty interval [UI] 3\ub74\u20134\ub76), corresponding to 291992000 (251513000\u2013341114 000) infections. Of these infections, around 29 million (10%) were diagnosed, and only 4\ub78 million (5%) of 94 million individuals eligible for treatment actually received antiviral therapy. Around 1\ub78 (1\ub76\u20132\ub72) million infections were in children aged 5 years, with a prevalence of 1\ub74% (1\ub72\u20131\ub76). We estimated that 87% of infants had received the three-dose HBV vaccination in the first year of life, 46% had received timely birthdose vaccination, and 13% had received hepatitis B immunoglobulin along with the full vaccination regimen. Less than 1% of mothers with a high viral load had received antiviral therapy to reduce mother-to-child transmission. Interpretation Our estimate of HBV prevalence in 2016 differs from previous studies, potentially because we took into account the effect of infant prophylaxis and early childhood vaccination, as well as changing prevalence over time. Although some regions are well on their way to meeting prophylaxis and prevalence targets, all regions must substantially scale-up access to diagnosis and treatment to meet the global targets

Global prevalence, treatment, and prevention of hepatitis B virus infection in 2016: a modelling study

Background: The 69th World Health Assembly approved the Global Health Sector Strategy to eliminate viral hepatitis by 2030. Although no virological cure exists for hepatitis B virus (HBV) infection, existing therapies to control viral replication and prophylaxis to minimise mother-to-child transmission make elimination of HBV feasible. We aimed to estimate the national, regional, and global prevalence of HBsAg in the general population and in the population aged 5 years in 2016, as well as coverage of prophylaxis, diagnosis, and treatment. Methods: In this modelling study, we used a Delphi process that included a literature review in PubMed and Embase, followed by interviews with experts, to quantify the historical epidemiology of HBV infection. We then used a dynamic HBV transmission and progression model to estimate the country-level and regional-level prevalence of HBsAg in 2016 and the effect of prophylaxis and treatment on disease burden. Findings: We developed models for 120 countries, 78 of which were populated with data approved by experts. Using these models, we estimated that the global prevalence of HBsAg in 2016 was 3·9% (95% uncertainty interval [UI] 3·4–4·6), corresponding to 291 992 000 (251 513 000–341 114 000) infections. Of these infections, around 29 million (10%) were diagnosed, and only 4·8 million (5%) of 94 million individuals eligible for treatment actually received antiviral therapy. Around 1·8 (1·6–2·2) million infections were in children aged 5 years, with a prevalence of 1·4% (1·2–1·6). We estimated that 87% of infants had received the three-dose HBV vaccination in the first year of life, 46% had received timely birth-dose vaccination, and 13% had received hepatitis B immunoglobulin along with the full vaccination regimen. Less than 1% of mothers with a high viral load had received antiviral therapy to reduce mother-to-child transmission. Interpretation: Our estimate of HBV prevalence in 2016 differs from previous studies, potentially because we took into account the effect of infant prophylaxis and early childhood vaccination, as well as changing prevalence over time. Although some regions are well on their way to meeting prophylaxis and prevalence targets, all regions must substantially scale-up access to diagnosis and treatment to meet the global targets. Funding: John C Martin Foundation