Application of Inflow Control Device (ICD) for Optimizing Horizontal Well Performance

Horizontal and multilateral wells are shaping the development of the oil and gas industry due to its increased reservoir contact. The horizontal well drilling technology was established about ten to fifteen years ago and has since become a method for improving hydrocarbon recovery. With its horizontal nature, the presence of a strong aquifer and gas cap facilitate the possibility of early water and gas breakthrough through a situation known as “heel toe effect” which is a result of frictional losses. Reservoir heterogeneities results into variations in permeability along the length of the wellbore causing unequal influx of the inflowing fluids around the vicinity of the wellbore. The unequal influx contributes to early water and gas breakthrough because the fluids flowing in the zones with higher permeability (thief zones) move faster than those moving in the low permeability zones, thereby allowing the low viscosity fluids to bypass the high viscosity fluids making the well uneconomical. This research paper studies the application of Inflow Control Devices (ICDs) as a means of eradicating or at least delaying the water/gas breakthrough. A simulation method has been identified by the author after a thorough review of literature. The implementation of ICDs is expected to improve hydrocarbon recovery and delay water/gas production. The multi-segment well model in the ECLIPSE Black Oil Simulator is used to represent a horizontal well divided into segments with ICD installed in some of the suitable segments. A set of data is used to demonstrate and address the problem of unequal influx of fluid and early breakthrough or higher production of water and gas. Two cases of different model dimensions have been discussed in this study and both cases show that proper application of ICD to the segments that provide optimum oil recovery and reduced water and gas production at the same time will improve performance of horizontal wells. The two cases also showed that oil production may decrease at the beginning when using ICD because of the additional pressure drop created by forcing the fluids to flow through the device. However, the rate will increase eventually over time and higher recovery will be achieved. Key words: ICD, Horizontal well, Performance, Multi-segment well model

PENDAMPINGAN KOMUNITAS PETANI "URBAN FARMING" DI KELURAHAN BUKIT SANGKAL KALIDONI KOTA PALEMBANG

Kota Palembang masih memiliki banyak lahan kosong yang belum dimanfaatkan oleh pemiliknya. Pendampingan bagi masyarakat urban farming di Palembang dapat menjadi solusi yang dapat memberikan jawaban dalam menekan inflasi dan mengurangi kemiskinan di Palembang. Tujuan pendampingan masyarakat urban farming di Kelurahan Bukit Sangkal Kecamatan Kalidoni adalah untuk memetakan potensi lahan kosong yang dapat dijadikan sebagai lokasi pelaksanaan urban farming dan juga potensi komoditas yang cocok dibudidayakan di kecamatan Bukit Sangkal. Hasil pendampingan menunjukkan bahwa pola pemberdayaan petani “urban farming” di Bukit Sangkal Kalidoni Kota Palembang telah dilakukan sebagai berikut: pemetaan lokasi urban farming selanjutnya dilakukan pemetaan potensi komoditas yang dapat dikembangkan . Pemetaan potensi komoditas ini dilakukan dengan melihat kondisi pertanian di Bukit Sangkal. Cara penanggulangan kemiskinan di perkotaan dengan pola urban farming sudah dilakukan di Bukit Sangkal namun tetap membutuhkan keterlibatan berbagai pihak untuk memberikan informasi dan penyuluhan tentang urban farming dan pola adopsi inovasi urban farming dan penggunaan lahan di lahan Bukit Sangkal. Pemanfaatan lahan kosong di kecamatan Bukit Sangkal belum optimal, hal ini ditunjukkan dengan banyaknya warga yang membuang sampah sembarangan di lahan kosong di kawasan Bukit Sangkal

Biooxidation kinetics of Leptospirillum Ferriphilum attached to a defined solid substrate

Includes abstract.Includes bibliographical references.Bioleaching can be categorized as being either stirred tank type (i.e. bio-oxidation) or irrigation type (i.e. heap/dump bioleaching) yet studies investigating the kinetics of bioleaching systems mostly use empirical data determined from stirred tank type and initial rate experiments in batch cultures or using iso-potential devices. Rate equations deduced from such empirical data is then used to model both the stirred tank type and irrigation type bioleaching systems overlooking the possibility that there may be significant differences in their environments and therefore the kinetics. Tank bioleaching systems are well mixed suspension systems dominated by planktonic microorganisms (freely suspended in the liquid medium). Heap bioleaching systems on the contrary, are heterogeneous in nature with chemical and physical conditions changing over time and are dominated by sessile microorganisms (attached microorganisms to the surface of a solid). The heap bioleaching system is therefore highly complex compared to the stirred tank-type systems. Microbial growth in bioleaching systems significantly influence the overall bioleaching kinetics yet biological kinetic effects in sessile/ attached environments are not well understood. Heap and dump leaching account for about 20% of the world’s copper production and are becoming popular methods of copper production from leaching low grade ores. It is therefore important that the kinetics of irrigation type bioleaching systems are well understood. A strategy to determine the microbial kinetics of a sessile microbial population is enforced in this study. From this, empirical data determined from irrigation type environments can then be used to derive equations which can be used to accurately model heap bioleaching systems. Three sets of experiments were conducted to try and achieve this: i. planktonic experiments - investigating the microbial kinetics of a planktonic microbial population ii. attachment experiments - investigating the nature of growth of the microbial population to the surface of a solid substrate during attachment to create a sessile microbial population iii. sessile experiments - investigating the microbial kinetics of the sessile microbial population A pure culture of Leptospirillum ferriphilum (a mesophilic, ferrous iron oxidizing bioleachingmicroorganism) was used in this study. Planktonic experiments were conducted in a completely mixed, well aerated continuous stirred tank reactor (CSTR) with a 1 litre working volume, operating at a pH of about 1.3 and temperature of 37oC. Attachment and sessile experiments were conducted using a CSTR with similar conditions to the planktonic experimental, however the system was modified by introducing a packed bed vessel (PBR) attached as a closed loop to the CSTR. Solution drawn from the CSTR was then continuously pumped through the PBR and back to the CSTR

Evaluating the optimal innovative cost control techniques used in the South African construction industry

The execution of construction projects commands a myriad of technological, human, organisational and natural resources. However, the construction and engineering undertaking of these projects are frequently overshadowed by economic difficulties, such as the high costs of construction materials, that have a negative impact on project costs. Cost overruns have been determined as a phenomenon continually plaguing the construction industry in both private and public sectors, and very few projects are completed within cost parameters. This research evaluated the barriers to the use of innovative cost control techniques during the construction phase, and determined the level of cost overruns on construction projects in South Africa; identified innovative cost control techniques used by construction firms on construction projects; established the optimal innovative cost control technique used in the South African construction industry; and uncovered the relationship between the level of use of innovative cost control techniques on construction projects and cost overrun. Questionnaires were the chosen instrument for data collection and were circulated via Survey Monkey. A total of 123 questionnaires were returned, and they provided the base for the computation of study results. Statistical tools employed in the study included percentages, mean item score (MIS), and frequency distributions. A scatter plot was used to distinguish whether there was a correlation between the cost performance of projects and level of innovativeness by establishing a line of best fit through the set of the two variables. A line of best fit in the positive direction indicates that increased levels of innovativeness improves the cost performance of projects, while a line of best fit in the negative direction indicates that increased levels of innovativeness does not enhance project performance. The relationship between the level of innovative cost control techniques usage in construction projects and cost overrun was determined to be negative. This led to the conclusion that construction professionals are limiting themselves and are not exploring alternative or innovative cost control techniques. They were focused on project efficiency and productivity rather than cost overruns. Innovative cost control techniques identified in the study were Earned Value Analysis (EVA), Last Planner System (LPS), 4D Scheduling, Fuzzy Project Scheduling, Integrated critical path and Line of Balance, and Reserve Analysis. Study findings determined that the critical contributors to cost overruns included tight project budgets, project complexity, a high frequency of change orders by clients and financial difficulties encountered by contractors. Perceived barriers to the implementation of innovative cost control techniques in projects by participants included a poor scope definition, a lack of training and technical skill of project personnel, poor understanding of cost analysis and variables involved in cost planning. It also emerged that projects cannot meet project objectives, and construction organisations are not making use of the right tools and techniques to monitor and control construction costs. The research findings have shown that professionals have limited knowledge of innovative cost control techniques. This also concludes that they are not taking advantage of the features of new innovative techniques to tackle complex projects. This, therefore, means that complex projects will continue to experience cost overruns. This study concludes that top management of construction organisations are not training their staff to embrace new technologies and innovation. To address the barriers to the use of innovative techniques, there should be increased investment on the part of construction organisations toward affording their workforce the relevant training, knowledge and technical skill required to implement the modern techniques for cost control identified in the report. The cidb should organise seminars and workshops on the usefulness and importance of innovative cost control techniques, and workers should embrace self-development and change. Government should implement policies on the use of innovative cost control techniques for their projects, and construction organisations should develop capacity in line with innovative cost control techniques

The Aftermath of 21st Century Sharia Implementation in Northern Nigeria

Enforcement of Sharia legal system is a duty bound over every Muslim (Male or Female) on their day to day life and activities. The objective of this paper is to examine the consequences after the implementation of Shari’ah law in 21st Century in Northern part of Nigeria. Therefore, this study addresses the major area of negation and setback in the implementation of Shari’ah law in 21st Century in Northern Nigeria. The study posit out that inconsistence of Nigerian constitution with Shari’ah law, capital offence punishable by Shari’ah law, Hisbah institution, lack of qualified and experts judges, political problem and many others are the setback encountered by means of Shari’ah implementation in Northern Nigeria. Conclusively, the study concludes that 21st Century Shari’ah implementation in Northern Nigeria faced with many challenges

Facilitating Inclusive Education in Ghana Through Art Education

The focus on the education of persons with special educational needs all over the world is shifting from special and segregated education to an inclusive education. This is to ensure equal access to education for all children. However, the goal of providing quality inclusive education in Ghana would remain elusive so long as the concept of inclusion is not linked to broader dimensions on curricular modifications and pedagogy for effective participation of all children in the learning experiences provided in the classrooms. The aim of this study is to facilitate inclusion through art education. This exploratory research utilised a semi-structured interview, extensive classroom observation, documentary review, and practical activities to gather data. The population for the study included head teachers, teachers and pupils in four schools which were targeted to have embarked on inclusive education in the Effutu Municipality in the Central Region of Ghana by the Special Education Division (SpED) of the Ministry of Education in 2003. Purposive sampling technique was adopted in selecting the 24 subjects for the study. The study revealed that Art could be used as catalyse in the implementation of Inclusive Education (IE) and also young people without disabilities became advocates of the rights of persons with disabilities for inclusive settings. It is recommended that teachers of art would benefit from in-service training that specifically addresses art education for students with special needs in inclusive settings. Keywords: art education, arts, inclusive education, special educatio

Pedagogic foundation of art education in Ghana

This paper is one of the discourses to holistically evaluate university art education curriculum in Ghana. The faculty of any course is responsible for setting the climate or tone for the dissemination of information. This is at times compounded by advancement in the technology used in the teaching and learning process. The problem of this study was to investigate the pedagogical underpinnings of art education in Ghana against the 21st century teaching and learning skills requirements. This exploratory research utilized both qualitative and quantitative methods. Findings indicated that majority of the respondents agreed that the faculty used variety of teaching methods and again, faculty employs technology to their advantage in making sure that students understand the concepts they impart and by the appropriate means available. Currently there is little mix in the Department of Art Education as most of the members of faculty are on the lecturer level. Keywords: pedagogy, art, education, evaluation and 21st century skill

Modelling the dynamic interactions between food production and ecosystem services : a case study in Benin

Given the high levels of food insecurity and the loss of vital ecosystem services associated with deforestation, countries in sub-Saharan Africa (SSA) face a major dilemma. How can they produce enough food in a changing climate to feed an increasing population while protecting natural forests and woodlands that provide a wide array of ecosystem services beneficial to livelihoods? Thus, the objectives of this thesis are twofold. First, to further enhance the understanding of the dynamic interactions between food production, and natural and semi-natural ecosystems with a case study in Benin. Second, to further enhance the understanding of how hydrological ecosystem services can be captured in an accounting framework. Understanding hydrological ecosystem services is key to understanding the multi-directional relationship between food production and ecosystem services supply from natural and semi-natural ecosystems. First, I examine how a spatially explicit ecohydrological model can be used to analyse multiple hydrological ecosystem services in line with the ecosystem accounting framework. The hydrological ecosystem services include crop water supply for rainfed agriculture, household water supply (both groundwater supply and surface water supply), water purification, and soil erosion control. Second, I develop a general modelling approach for analysing the effects of deforestation on the availability of water for irrigation at the watershed level, and I apply the approach to the Upper Oueme watershed in Benin. Third, I analyse the impact of climate change on agricultural intensification options. Finally, I quantify trade-offs between per capita food availability and protecting forests and woodlands at different levels of yield increases taking into account climate change, population growth. This thesis shows that the integration of hydrological ecosystem services into an accounting framework can provide relevant information at appropriate scales suitable for decision-making. It is empirically feasible to distinguish between service capacity and service flow of hydrological ecosystem services. This requires appropriate decisions regarding physical and mathematical representation of ecohydrological processes, spatial heterogeneity of ecosystems, temporal resolution, and required model accuracy. This thesis also shows that opportunities for irrigation expansion depend on conservation of forests and woodlands in the headwaters of the rivers feeding the irrigation scheme. Opportunities for agricultural intensification in SSA are likely to diminish with climate change, hence increasing pressure to expand cultivated areas in order to meet increasing food demand. Climate change will lead to substantial reductions in; exploitable yield gaps for major food crops, rainfed cropland areas that can support the cultivation of two or more crops per year, and water availability for irrigation expansion. Furthermore, in the far future crop yields will have to increase at a faster rate than has been recorded over the past two and half decades in order to maintain current levels of per capita food availability. Failure to achieve the required levels of yield increases is likely to lead to the conversion of substantial areas of forests and woodlands for crop cultivation. Based on the results of this thesis, four main recommendations to help address the dual challenge of food security and ecosystem protection in Benin and the larger SSA region are made: (i) promote a precautionary approach to forest and woodland conservation, (ii) promote cross-sectoral policy coherence and consultations, (iii) promote the development of satellite ecosystem accounts consistent with national accounts, and (iv) identify, evaluate and implement adaptation and resilience measures to reduce agricultural vulnerability to climate change.</p