bluuebunny/crossref_metadata_2025_split huggingface dataset:
Otter North Sea Subsea Field Development: Sand-Control Strategy and Implementation
Authors: Profinet Jérôme , Petit Gérard , Goyallon David , Horn Mark , Furgier Jean-Noël 
Published: April 2006

Summary
The Otter field is the first "dual" electric submersible pump (ESP) completion in the U.K. sector of the North Sea in a subsea field development. This subsea development consists of three horizontal openhole oil producers and two cased-hole water injectors clustered around a production manifold and tieback, 21 km from the Eider host platform. Each oil producer has been able to deliver up to 20,000 BOPD since October 2002. Because a risk of sand production was identified during the life of the field, downhole sand control was deemed necessary.
Well longevity has a major impact on the global-project economics. This meant that achieving and maintaining sand-free production through optimal completion design was critical to the overall success of the development.
This paper describes the strategy adopted and the factors considered in the development of the sandface completion design for the field's life. The sand-control technique had to be decided upon while drilling the well, on the basis of the drill cuttings-particle-size analysis—oversmall particles would have lead to an openhole gravel pack. It appeared that correct geosteering was permitted to stay within a sand body that was adequate for standalone screen completion, which the authors consider the best option (i.e., in cost, risk, and efficiency) when applicable. The operational experience gained and lessons learned on the first well contributed to the design enhancements required for completion of the horizontal wells described in this paper.
Study of Calcium Carbonate Precipitation in the Near-Well Region Using47Ca as Tracer
Authors: Stamatakis E. , Haugan A. , Chatzichristos C. , Stubos A. , Muller J. , Dugstad Ø. , Palyvos I. 
Published: April 2006

Summary
Calcium carbonate scale formation during flow in porous media was studied using radioactive tracer technology; in a series of calcite scaling experiments in sandpacks,47Ca was used as a tracer to monitor CaCO3 deposition. In these experiments, the induction time and the distribution of scale deposition were studied as a function of saturation ratio, temperature, flow velocity, the presence of Mg ions, and the type of packing material. The results show that the radiotracer method gives a fast response to scaling events. The technique is applicable for dynamic scaling investigations in any flowing system in porous media and constitutes a valuable tool for further studies of scaling mechanisms involved in processes occurring in a variety of systems (oilfield, geothermal, and desalination).
Evolution of Completion Practices in the Wild River Tight Gas Field
Authors: Colwell D. A. F. , O'Brien C. G. J. , Gates T. D. 
Published: April 2006

Summary
This paper presents the evolution of completion practices and fracture stimulation that has taken place in the Wild River area of Canada over the past 2 years. Since being acquired in March 2001, 67 wells have been drilled and completed in the field, which is characterized by multiple stacked, tight gas reservoirs. During that time, seven distinct completion phases can be identified, each targeting either a reduction in the total capital expenditure or enhancement of production performance by fracture-stimulation optimization. On the capital front, a progression of completion tools occurred including standard bridge plugs, proprietary permanent frac-packer systems, and composite bridge plugs. Focus areas for production performance improvement included fluid systems, proppant selection, perforating strategy, energizing fluids, and third-party quality control. As a result of this evolution, the average completion cost per zone has been reduced by approximately 40% and the average initial production rate has been increased by approximately 150%.
A New Formation-Evaluation Technique for the Lower Tertiary in South Texas—Predicting Production in Low-Permeability, Fine-Grained Sandstones
Authors: Rasmus John C. , Horkowitz John P. , Chabernaud Thierry , Graham Peter , Summers Malcolm , Wise Danny 
Published: April 2006

Summary
The lower Tertiary Wilcox, Yegua, and Vicksburg formations are prolific natural gas plays in south Texas that have been extensively drilled and produced from low-permeability, fine-grained sandstones. It is not unusual to encounter several potential pay zones in each well. What is lacking is a proven formation-evaluation method to determine the highest-productivity water-free producing zones from multiple intervals that can be casually identified on the logs as hydrocarbon-bearing. Connate-water resistivity (Rw) determination is not a major problem, given that many water-bearing sands are usually present. Accurately estimating true clay content, porosity, irreducible water volumes, and permeability present the greatest challenges.
A new spectroscopy-based petrophysical interpretation methodology has been developed that makes use of several unique measurements, namely quantitative elemental concentrations and lithology logs obtained from capture gamma ray spectroscopy devices in open or cased wells. These measurements allow us to more accurately define the clay content, mineralogy, and matrix properties of each potential zone. One significant finding obtained from these measurements is the occurrence of calcite cements detected in many sands that cause a pessimistic density porosity to be computed if not accounted for. This calcite cementation appears to vary dramatically in a lateral sense, indicating that its presence should not be used to condemn an entire layer as being too tight for production, nor provide irrefutable evidence of the expected ability of the layer to contain a hydraulic fracture.
The enhanced elemental and mineralogical analyses provided by the spectroscopy measurements also allow for more accurate bulk volume irreducible water calculations and a means to correct the neutron porosity for clay and matrix effects. By comparing irreducible water volume to bulk volume hydrocarbon, an accurate prediction of water production can be determined. Oil- and gas-bearing intervals can be identified easily from crossover of the matrix-corrected neutron porosity when used in conjunction with the matrix-corrected density porosity. Results are illustrated with several case studies from wells recently drilled and now producing from the Wilcox, Yegua, and Vicksburg formations.
The Continuous-Circulation System: An Advance in Constant-Pressure Drilling
Authors: Jenner J. W. , Elkins H. L. , Springett F. , Lurie P. G. , Wellings J. S. 
Published: April 2006

Summary
In late July 2003, for the first time since rotary drilling was introduced, a section of hole was drilled without interrupting circulation while new joints of drillpipe were added to the drillstring. This was made possible by the use of the continuous-circulation system (CCS), developed over the previous 3 years by a joint industry project (JIP) that was managed by Maris Intl. and funded by six major oil companies (Shell U.K., BP, Statoil, BG, Total, and Eni),Coupler Development Ltd., and Varco, and supported by the U.K.'s Industry Technology Facilitator. The field trial of the CCS was carried out on a land well being drilled in Oklahoma, U.S.A. Its success marked the end of the JIP and the commencement of commercial development of the system.
The CCS is a new and enabling technology; the potential benefits of which include the following:
Elimination of negative and positive pressure surges when stopping and starting circulation to make a connection. No rig downtime to circulate out cuttings to clear the bottomhole assembly before making a connection. Improved drilling-fluid management. Elimination of kicks on connections. Improved control of equivalent circulation density (ECD). Reduced total connection time (TCT). Reduced chance of stuck pipe during a connection. No downtime in high-pressure/high-temperature (HP/HT) wells to circulate out connection gas. Reduced wellbore "breathing" or "ballooning." Improved safety around the rig floor.
Potential applications of the system include the following:
Extended-reach drilling (ERD) and horizontal wells. HP/HT wells. Near or underbalance wells. Deepwater wells.
The CCS is also a potential-enabling technology in achieving the "one-tripwell."1 The concept was presented in a paper by inventor L. Ayling at the Offshore Technology Conference, May 2002.2
Cost-Effective Sand-Control Operations Play Key Role in Revitalizing a Mature Gas Field
Authors: Ripa Giuseppe , Ligrone Angelo , Zamparini Angelo , Sportelli Marco , Mathis S. P. , Conte Antonio 
Published: April 2006

Summary
When revitalizing mature oil or gas fields, the ability to maximizeproductivity while minimizing operating costs is critical. Achieving thesegoals becomes more challenging where sand control is required. This isespecially true in connection with a complex reservoir lithology, which leadsto a variety of fracture and pore pressure gradients and premature waterbreakthrough. In addition, reduced deliverability resulting from pressuredepletion presents additional complications related to achieving acceptableproject economics.
The Barbara field, located in the central Adriatic Sea, is an example ofthis type of reservoir. For this project, a dedicated work team wasassigned to identify and implement the solutions to improve field performancethrough continuous operations optimization. The Barbara field consists ofstacked pay sections that have been depleted since the early 1980s. Toachieve favorable economics, techniques had to be used that would do both:maximize the deliverability of each well and minimize operational costs.
This paper reviews the Barbara field workover program. The evolution oftechniques, equipment, and products leading to enhanced productivity whilesubstantially reducing costs is described. The fluid systems and operationprocedures designed to optimize frac-pack geometry are discussed. Inaddition, the one-trip multizone gravel-pack assemblies are described thatallow multiple zones to be individually fracture packed in a single run, thusproviding significant rig-time reductions without sacrificing completionefficiency. Finally, the complex nature of this reservoir dictates theneed for a variety of completion techniques. This means that fracturepacking was not necessarily an option for all zones. For the intervals atwhich fracturing was not employed, productivity still needed to bemaximized. To accomplish this goal, perforation tunnel-cleanup procedureshave been optimized.
Wage labourers in the fragmented labour market of the Gezira, Sudan
Authors: Abdelkarim Abbas 
Published: April 2006

Opening ParagraphThe Gezira scheme has been the focus of considerable attention in the literature of development in tropical Africa, especially during the colonial period. This was because the scheme represented one of the largest agricultural projects initiated by a colonial government. Views on the scheme have been divergent: Gaitskell (1959) describes it as a ‘story of development’ while Barnett (1977) calls it an ‘illusion of development'. The focus of the studies, which are extensive compared to other Sudanese studies, has largely concentrated on the relationship (or so-called partnership) between tenants and government, production requirements and output, as well as occasionally on various aspects of the tenants’ lives and activities. Wage labour, which is the main form of labour, has only been given scant consideration. Even so, the focus has been on its contribution to the total labour requisite and its supply and demand patterns. The social relations of wage labour, and especially relations between tenants and wage labourers as the essential core of production relations in the scheme, have been awarded very little attention. This is the main concern of this article. Compared with most labour-market studies, my intention is to go beyond a mere study of factors affecting supply and demand. In conditions of transition to capitalism and fragmented labour markets, the perception of the social and cultural aspects of labour is indispensable for an adequate understanding of the internal mechanisms of the labour market.
A subsistence society under pressure: the Bemba of northern Zambia
Authors: Stromgaard Peter 
Published: April 2006

Opening ParagraphThe research upon which this article is based was carried out over a period of four months in the Northern and Luapula Provinces of Zambia. Before that, I spent two years working in the area as an agricultural officer. One of the villages described in the article is situated on the western shore of Lake Bangweulu, the other 20 km south of Kasama, the major city of Northern Province, the homeland of the Bemba (Fig. 1). The area is almost exclusively devoted to chitemene shifting cultivation, an agricultural system where crops are grown in the ash from burning the collected, stacked branches that have been lopped and chopped from an pressure, vegetation is now chopped before it is fully regenerated, and the system seems to be starting to break down. A major task during my field stay was to describe the ecological (Stromgaard, 1984a) and economic (Stromgaard, 1984b) aspects of this change, but it soon became apparent that subsistence activity and social structure deeply influenced the village's economic activities.
Social change in eighteenth-century Anlo: the role of technology, markets and military conflict
Authors: Greene Sandra E. 
Published: April 2006

Opening ParagraphTechnological change among the Anlo-Ewe of southeastern Ghana is a subject that has received little attention from scholars, but it is a theme which figures prominently in Anlo oral tradition. Of the technologies mentioned, those associated with lacustrine fishing and salt making are discussed in the greatest detail. Traditional accounts of the fishing industry, for example, agree that when the Ewe-speaking Anlo first settled in their present area (located on the Atlantic coast immediately east and south of the Volta River and Keta Lagoon system) the Anlo were not familiar with the use of boats. As a consequence they employed fishing techniques that restricted such activities to the more shallow sections of the Keta Lagoon. The first boat that was developed (the agowu, made by hollowing out the trunk of the fan palm [Borassus aethiopium]) was said to have been inefficient because it capsized easily (Greene, 1981b: no. 29). A more stable vessel, still in use today and known as the lewu, was introduced, according to the traditions, by Amega Le.
The Quranic school farm and child labour in Upper Volta
Authors: Şaul Mahir 
Published: April 2006

Opening ParagraphOn his way back from his first travels to the interior of the Gambia, Mungo Park describes a ‘schoolmaster’ who entertained him in the Mandingo country while his principal host was on a slave purchasing expedition. The school of this master consisted of seventeen boys who ‘always had their lessons by the light of a large fire before daybreak and again late in the evening’ and who ‘were employed in planting corn, bringing firewood, and in other servile offices, through the day’ (Park, 1799: 313–14). Such rural institutions combining elementary Islamic education and farm production must then have existed in the coastal areas of West Africa for at least two centuries, and spread to other parts of Africa as a result of Islamic expansion. They were agents of proselytization and further Islamization. Consequently Quranic schools are often discussed primarily in their relation to Islamic history. In the present day, however, they continue in some areas as viable alternatives to western-style schools and as units of agricultural production. This paper, which stems from research I conducted in the southern part of central Upper Volta on household farms and wealth stratification, underscores the dual function of these farm schools.
Stock theft and moral economy in colonial Kenya
Authors: Anderson David 
Published: April 2006

Opening ParagraphFrom the earliest years of colonial government in Kenya, cattle raiding by Africans against their neighbours, and in particular livestock thefts from European farmers, presented the administration with their most persistent policing problem in the rural areas of the colony. As the period of colonial rule in Kenya was drawing to a close, reported cases of stock theft were once again showing a sharp increase, climbing from 1578 cases in 1955 to 4243 in 1962 (Kenya Police Dept, 1955 and 1962). In a pattern by then familiar to the Kenya administration, this prompted the renewal of demands from the European settler community for more extensive and concerted government action to deal with the activities of the thieves. Settler opinion held that the continuing prevalence of stock theft had much to do with the ‘social prestige’ attached to the crime in many African communities. The unwillingness of the African public to assist in the prevention and detection of stock theft had long been interpreted as a tacit sanctioning of such theft, leading to the conclusion that, within the ‘moral economy’ of many African communities, stock theft was not thought of as a crime at all. ‘After all,’ commented the Provincial Commissioner of the Rift Valley Province in 1959, ‘stock theft is the traditional sport of the young men of many tribes, and the elders cannot be expected to act as kill-joys and stamp it out unless they themselves are liable to suffer.’ This view was applied most readily to the pastoralists of the Rift Valley and western Kenya, the Maasai and Kalenjin, who were commonly involved in crimes of this sort. The belief that stock theft was an acceptable form of accumulation within Kalenjin and Maasai society determined the nature of the legislation put forward by the colonial administration to deal with the crime. Policing and punishment were accordingly based upon the notion of collective responsibility for acts of stock theft, with wide powers to extend collective punishments to families, villages and even entire locations found to be implicated in thefts.
Oríkì, women and the proliferation and merging ofòrìṣà
Authors: Barber Karin 
Published: April 2006

1. Two Faces of Yoruba ReligionThe proliferation and overlapping of spiritual beings is a feature of many religions. Saints in popular Catholicism and Vishnu'savatārasin Hinduism represent, in different ways, the possibility of spiritual beings that are simultaneously one and many, clusters or series of manifestations whose inner relationships are often not fully explained. Yorubaòrìṣàare in good company. However, the way in which multiple aspects of gods are made and maintained clearly varies from one religious repertoire to another. I suggest that it is important to look at the means or medium by which fractions of gods are established, in order to understand how the relationships between them are conceived. Yorubaòrìṣàcan scarcely be apprehended without taking into account the specific textuality of the oral genres through which they are created, maintained and communicated with.
Approaches to the economy of colonial Annaba, 1870–1920
Authors: Prochaska David 
Published: April 2006

Opening ParagraphThe Annaba economy today is Algerian. It is run entirely by Algerians except for the steel mill outside of town. The goods provided are tailored to its mostly Algerian customers (jillabas, harissa, henna), plus selected Western goods made in Algeria or imported from Europe (plastic buckets and gas bottles, Peugeot sedans for those with the money and connections, sitcoms for the few with TVs, commercial films for everyone). Goods are dispensed primarily in a modern suq, or bazaar, although the government also runs a supermarket and department store. French and other Europeans are physically absent from Annaba today for the most part, but Western economic influences persist, like only partly covered-over layers of historical sediment laid down orignally in the colonial period.
The greater risk of fewer deaths: an ethnodemographic approach to child mortality in Hausaland
Authors: Ross Paul J. , Etkin Nina L. , Muazzamu Ibrahim 
Published: April 2006

AbstractA Nigerian case study illustrates how local understandings of health influence perceptions of infant survival in ways that may juxtapose indigenous interpretations to other ‘objective’ data. Evidence from two extended field investigations of a Hausa-Fulani village, set 12 years apart, suggests a decline in childhood mortality rates attendant upon the increasing availability of biomedicines. We note, however, that local perceptions are that mortality risks are now greater for those less than five years old. Our discussion focuses on the circumstances that inform this ethnodemography and its applicability to other population studies.
The social stuff of revelation: pattern and purpose in Zionist dreams and visions
Authors: Kiernan J. P. 
Published: April 2006

Opening ParagraphAnthropologists are beginning to investigate the sociological dimension of dreams, at least of those purporting to be channels of religious revelation. Two recent examples of this tendency are Charsley (1973) and Curley (1983), each of whom researched dream phenomena in an African independent church. The sociological approach is a firm rejection of earlier and some current attempts to extract patterns of culture and personality from the subjective reconstruction of the dream-as-dreamed, a purely private event. In contrast, the sociological emphasis isolates as its primary datum the dream-as-told to others, an essentially social act, which leads to an analysis of dreams as social assets, which can be manipulated to advantage or disadvantage. Consequently, the method of analysis demands that as much attention be directed to the act of recounting as to the content of the narration, although in practice this seems to mean that content is subordinated to purpose and can be related to social arrangements only indirectly through purposive action. I shall endeavour to correct this latter impression in subsequent argument. The second methodological requirement is to connect narration to social action, social relations and social organization, and to demonstrate the tactical use of dreams in social encounters.
The fertile past: the Gabra concept of oral tradition
Authors: Kassam Aneesa 
Published: April 2006

Opening ParagraphThis study on the concept of oral tradition is based on three years of fieldwork, between 1980 and 1983, amongst the Gabra of northern Kenya, an Eastern-Cushitic (Oromo) speaking people who originated in southern Ethiopia and who live today on both sides of the Kenya–Ethiopia border. According to the 1978 national census figures, there are about 30,553 Gabra living on the Kenyan side of the border, mainly in the arid waste of the Eastern Province. In this hostile landscape, in the volcanic, boulder-strewn country on the edge of the Chalbi Desert east of Lake Turkana, the Gabra roam with their herds of cattle, camels, sheep and goats in constant search of pasture for their animals.
<Age, generation et temps> chez les Meru tigania-igembe du Kenya
Authors: Peatrik Anne-Marie 
Published: April 2006

AbstractOur understanding of the sociahorganisation of the Meru Tigania-Igembe (Kenya) now makes it possible to propose a new approach to those East African societies which have age and generation classes. The way these classes are defined and the various rules by which they are set up and recruit members reveal the interconnections between the system of classes and other aspects of Meru society. Most illuminating is the way an individual's actual progress through the stages of life does or does not match his or her progress through the age classes, with their ramifications into descent and marriage as well as into territorial organisation. It is now possible, we believe, to construct a sociology of age and generation class societies, building a model that can be used comparatively. With the data from Meru, we can now include Bantu societies alongside the well known Cushitic and Nilotic examples, and thereby elucidate both the social variables involved and the underlying structures.