bluuebunny/crossref_metadata_2025 huggingface dataset:
A Recent Gulf of Mexico Cavity Completion
Authors: Palmer Ian , Vorpahl Douglas G. , Glenn John M. , Vaziri Hans , McLennan John
Published: April 2006

Production was dramatically improved by cavitating (i.e., intentionally producing sand) an offshore gas well on the Gulf of Mexico shelf. The cavity completion was conducted over a period of 10 days and involved producing the well with temporary equipment to safely produce, collect, and dispose of the produced sand. No hydrocarbon emissions resulted because production could be routed back through the permanent facilities. Following the operations, the well was returned to flow through the permanent facilities at a much higher producing rate, with much lower sand production.

Before the cavity-completion operations, the well had been choked back to a low gas rate (<1 MMscf/D) because of sand production. The low gas rate was insufficient to continuously lift liquids, causing the well to become liquid loaded and/or slug. The well was evaluated for a sand-control completion, but this type of repair was believed to entail too much economic risk because of significant reservoir unknowns. Further evaluation suggested that the well had the attributes for successful cavity completion.

This paper discusses the cavity-completion evaluation process employed and the operational results and learnings; a similar process may be applicable too ther wells.
Benchmarking the Formation Damage of Drilling Fluids
Authors: Zwaag C. H. van der
Published: April 2006

The unified test protocol for laboratory formation-damage assessments consists of functional procedures that attempt to standardize formation-damage service projects. Setting functional requirements was preferred above comprehensive equipment specifications and detailed instructions on laboratory work processes.

To assess the formation-damage potential of a fluid for drilling or well operations, three sections of the protocol need to be accomplished: Information, Simulation, and Analysis.

This paper presents the three sections and discusses the effect of the functional approach. Special emphasis is put on a distinction between well fluids that experience dynamic- and static-filtration regimes, because these require different ways of simulating fluid applications to the rock sample. To provide engineering parameters relevant to field scale and to identify the full range of potential formation-damage mechanisms that may affect the reservoir, analyses on cm, mm, and μm scales are suggested.

Minimum requirements to scaleup formation-damage measurements to field scale are presented. Also, an option for full-scope diagnostic formation-damage assessments is demonstrated.

Applications of numerical models that have been suggested in earlier research yield return permeability, filtrate-invasion depth, laboratory skin, efficiency of flow, and loss of revenue as parameters to benchmark the formation damage of well fluids.
Production Improvement for Horizontal Wells in Sumatra
Authors: Gunarto Ronny , Tran Thanh B. , Widyantoro Barkah , Kritzler Torsten
Published: April 2006

Several horizontal wells have been drilled in different sandstone formations in Sumatra. These formations have a typical permeability of 100 to 500 md, a low bottomhole pressure (BHP) of 450 to 750 psi, and a bottomhole temperature (BHT) of approximately 200°F. The wells are completed with a perforated liner. The objective of the horizontal-drilling program was to increase oil recovery in low-permeability estuarine reservoirs. Some of the drilled horizontal wells did not perform to expectations, and an intensive study was undertaken to identify completion and stimulation opportunities to increase production.

During this study, all aspects of the initial completions were examined and redesigned.

The drill-in mud was reformulated to reduce the amount of polymer and increase the use of fine calcium carbonate to decrease lost circulation during drilling and to simplify the removal of filter cake during initial completion.

Core tests were performed to identify the optimum fluid formulation, which dissolves the remaining filter cake but does not destroy the formation's natural permeability.

A new way of removing the filter cake after completing the well was introduced using oxidizer technology.

A new, true-fluidic oscillator (TFO) was used to remove near-wellbore skin (in conjunction with an improved acid system) for wells that have been producing for several months or years.

The paper presents several case histories to discuss how completion and stimulation problems were systematically evaluated resulting in increased horizontal-well production.
A Simple Model for Predicting Heat Loss and Temperature Profiles in Insulated Pipelines
Authors: Guo Boyun , Duan Shengkai , Ghalambor Ali
Published: April 2006

Accurate predictions of heat loss and temperature profile in oil-and gas-production pipelines are essential to designing and evaluating pipeline operations. Although some sophisticated computer packages are available for such purposes, their accuracies suffer from numerical treatments and model-building skills of inexperienced users. A simple and accurate analytical heat-transfer model is highly desirable.

This paper presents three analytical heat-transfer solutions for predicting heat loss and temperature profiles in pipelines transporting petroleum fluids. The three solutions consist of one steadystate-flow solution and two transient-flow solutions. The two transient-flow solutions are for startup mode and flow-rate-change mode (shutting down is a special mode in which the flow rate changes to zero). An application example is presented to illustrate how the models can be used in insulation design of an offshore pipeline.
Framework for Field Optimization To Maximize Asset Value
Authors: Bailey William J. , Couët Benoît , Wilkinson David
Published: April 2006

In this paper, we propose an optimization framework for maximizing asset value, both with and without uncertainty. We first present the methodology to treat a general control optimization in the presence of uncertainty, followed by a brief section on the optimization algorithms used. We then describe the field model example used to illustrate the application of the methodology. Through a systematic analysis of various deterministic and stochastic cases, we address the various objectives sought. Using net present value (NPV) as a measure, we also explore the valuation of advanced completions along with the returns gained from expanding surface gas-handling facilities. The method also generates an efficient frontier that can be used for risk and decision analysis. The results clearly demonstrate the value of such a framework for value maximization in planning both near- and long-term time horizons as well as providing the necessary foundation for maximizing asset value.
Measurement of Total Alkalinity and Carboxylic Acid and Their Relation to Scaling and Corrosion
Authors: Tomson Mason B. , Kan Amy T. , Fu Gongmin , Cong Lili
Published: April 2006

Alkalinity is needed in many water-treatment calculations such as scale, corrosion, precipitation, and oxidation, yet the concept is often misunderstood. In natural waters, alkalinity often is not equal to bicarbonate concentration, because natural waters contain base-contributing anions that can significantly affect alkalinity. However, alkalinity is commonly assumed to be equal to the bicarbonate concentration in many scale- and corrosion-prediction algorithms. When other anions (e.g., carboxylates) are present, bicarbonate concentration in production tubing is not a conservative quantity; it varies with CO2 partial pressure, temperature, and carboxylate concentrations in a complicated manner up and down a well.

Reliable methods to accurately measure true alkalinity are scarce, especially when multiple weak acids are present and the effects of TDS on electrode and color endpoint are significant. Oilfield brines contain aliphatic carboxylic acids of one to six carbons (e.g., acetate) up to 5000 mg/L. The highest concentrations of carboxylates tend to be in waters from reservoirs at temperatures of 80 to 100°C. In this paper, a new analytical procedure and computation routine to determine alkalinity and carboxylic acids simultaneously will be discussed. The procedure was recently debugged and simplified by the Rice U. Brine Chemistry Consortium (Rice BCC). The new titration method is based upon simultaneous analysis of the titration curve determined at fixed PCO2 and emphasizes the titration shape (profile) instead of the endpoint inflection as is done presently.

A wide range of natural and synthetic waters has been tested. Excellent agreement was observed between the true and calculated carboxylic acid concentration with a correlation coefficient squared of 0.9986. Once the total alkalinity and acetic acid concentrations are determined, the theoretically correct bicarbonate concentration and/or pH at any given operation temperature or pressure can be calculated. The intricate interrelationship of total alkalinity, carboxylic acids, and pH on scale and corrosion will be discussed by using case studies.
Reaction Kinetics of the Uptake of Chromium(III) Acetate by Polyacrylamide
Authors: Jain R. , McCool C. S. , Green D. W. , Willhite G. P. , Michnick M. J.
Published: April 2006

Gelled polymer treatments applied in injection and production wells are used to alter fluid flow in oil reservoirs so that oil production is increased and water production is decreased. A common gel used in field treatments is made by crosslinking partially hydrolyzed polyacrylamide (HPAM) with chromium acetate. The initial step of the crosslink is the uptake of chromium acetate by a carboxyl group on the HPAM. The kinetics of the uptake reaction was studied as functions of the concentrations of chromium, HPAM, and hydrogen ions. The data were regressed to derive a rate expression for the disappearance of unreacted Cr(III) in the gelant.
Composition Routes for Three-Phase Partially Miscible Flow in Ternary Systems
Authors: LaForce Tara , Johns Russell T.
Published: April 2006

Three-phase flow often occurs in reservoirs, particularly for secondary or tertiary oil recovery methods such as miscible gas or chemical flooding. In these cases, there is often significant mutual solubility of components in the phases. Unfortunately, there is insufficient understanding of how three partially miscible phases can affect flow. Furthermore, there are currently no benchmark analytical solutions available to validate numerical simulations for this complex flow regime.

In this research, compositional solution routes are developed by the method of characteristics (MOC) for 1D, dispersion-free flow wherein up to three partially miscible flowing phases may be present. The method is applied to a water/alcohol/oil system that exhibits a large three-phase region in laboratory experiments. Unique solutions are found based on continuity arguments, shock-jump conditions, entropy constraints, and velocity constraints. The analytical solutions are compared to fine-grid finite-difference simulations to verify that they converge to the same dispersionfree limit.

The results show that composition routes within the three-phase region often exhibit one phase below its residual saturation so that only two phases are flowing. As miscibility is approached, cumulative oil recovery initially declines because of the development of constant states in the solution, which cause the leading shock to speed up. We show that multicontact miscibility is developed at the critical point of one two-phase region and along the boundary of the three-phase region where all shocks and waves flow at a dimensionless velocity of one. Last, we show that injectivity changes by a factor of two for the specific relative permeabilities and injection compositions used.
Drift-Flux Parameters for Three-Phase Steady-State Flow in Wellbores
Authors: Shi H. , Holmes J. A. , Diaz L. R. , Durlofsky L. J. , Aziz K.
Published: April 2006

Drift-flux models represent multiphase flow in wellbores or pipes in terms of a number of empirically determined parameters. Because of the lack of data for two- and three-phase flow in large-diameter inclined pipes, existing parameters are commonly based on small-diameter pipe experiments, which can lead to significant errors when the models are applied to wellbore flows. In this work, we use recent large-diameter experimental data for the determination of drift-flux parameters for oil/water/gas flow. The parameters are computed through application of an optimization procedure. It is shown that in-situ gas volume fraction in three-phase systems can be estimated using a two-phase flow model by viewing the system as an effective gas/liquid system, with oil and water constituting the "liquid" phase. This approach is, however, generally inaccurate for the determination of oil and water holdups, in which case the effect of gas must be taken into account. Specifically, for pipe inclinations away from horizontal, even small amounts of gas can act to eliminate the slip between oil and water. As the pipe deviation approaches horizontal, however, oil/water slip persists, even in the presence of gas. We develop and apply a unified two-and three-phase flow model to capture this gas effect. The new model is shown to provide much more accurate predictions for oil and water holdups in three-phase systems than were achievable with previous models.
Well-Test Analysis of Horizontal Wells in Gas/Condensate Reservoirs
Authors: Hashemi A. , Nicolas L. M. , Gringarten A. C.
Published: April 2006

Gas/condensate reservoirs usually exhibit complex flow behaviors owing to the buildup of condensate banks around the wells when the bottomhole pressure drops below the dewpoint pressure. The formation of this liquid saturation can lead to a severe loss of well productivity and, therefore, lower gas recovery. Several studies have examined various ways to minimize the pressure drop in order to reduce liquid dropout and related problems. One solution implemented over the past decade is the use of horizontal wells.

There is a lack of published knowledge on the flow behavior of horizontal wells in gas/condensate reservoirs. The limited studies in this area (Muladi and Pinczewski 1999; Dehane et al. 2000; Harisch et al. 2001) focused on well performance rather than on well-test behavior. There has been no evidence of condensate dropout effects in published horizontal-well-test data.

This paper presents preliminary results from a study aimed at establishing an understanding of the near-wellbore well-test behavior in horizontal wells in gas/condensate reservoirs, with a focus on the existence of different mobility zones caused by condensate dropout.

We used a 3D fully compositional model to develop derivative shapes to be expected from horizontal-well-test data in gas/ condensate reservoirs below the dewpoint under various conditions. We then analyzed actual well-test data that exhibit such derivative characteristics, using a uniform flux horizontal well with wellbore storage and skin model and appropriate reservoir boundaries. The condensate drop effects in the production tests have been accounted for through changes in the values of the total skin effect. Finally, we used a compositional model to verify the results obtained from conventional well-test analysis.

It was found that condensate deposit near the wellbore yields a well-test composite behavior similar to what is found in vertical wells, but superimposed on horizontal-well behavior, which makes it much more complex.
An Improved Implementation of the LBFGS Algorithm for Automatic History Matching
Authors: Gao Guohua , Reynolds Albert C.
Published: April 2006

For large scale history matching problems, where it is not feasible to compute individual sensitivity coefficients, the limited memory Broyden-Fletcher-Goldfarb-Shanno (LBFGS)is an efficient optimization algorithm, (Zhang and Reynolds, 2002; Zhang, 2002). However, computational experiments reveal that application of the original implementation of LBFGS may encounter the following problems: (i) converge to a model which gives an unacceptable match of production data; (ii) generate a bad search direction that either leads to false convergence or a restart with the steepest descent direction which radically reduces the convergence rate; (iii) exhibit overshooting and undershooting, i.e., converge to a vector of model parameters which contains some abnormally high or low values of model parameters which are physically unreasonable. Overshooting and undershooting can occur even though all history matching problems are formulated in a Bayesian framework with a prior model providing regularization.

We show that the rate of convergence and the robustness of the algorithm can be significantly improved by: (1) a more robust line search algorithm motivated by the theoretical result that the Wolfe conditions should be satisfied; (2) an application of a data damping procedure at early iterations or (3) enforcing constraints on the model parameters. Computational experiments also indicate that (4) a simple rescaling of model parameters prior to application of the optimization algorithm can improve the convergence properties of the algorithm although the scaling procedure used can not be theoretically validated.
Improved Drilling Performance in a Troublesome Environment
Authors: Russell K. A. , Jolley S. J. , Koster M. , Crawford A. , Davison M. , Kazi M. , McGrath B. , Cockburn C. , MacLure R.
Published: April 2006

This paper describes an example of drilling-hazard mitigation. It demonstrates how a completely fresh approach, involving geomechanical analysis, planning of a new revised well trajectory, and real-time well monitoring, can reduce nonproductive time and cost and mitigate against unplanned terminal events.

Recent drilling operations in a mature field in the North Sea were severely disrupted by wellbore deterioration, stuck pipe, and lost-circulation incidents. A complex geological sequence of tilted fault blocks and partially depleted reservoir sands made well-trajectory and wellbore-stability planning difficult. After two unsuccessful sidetrack attempts, an integrated operator/contractor team performed a detailed audit of the drilling problems and built a geomechanical Earth model to evaluate drilling hazards and develop strategies to mitigate any further wellbore instability. Well objectives were re-evaluated, and a new approach to the drilling process was developed. The keywas simplification of the well path. The operational solution featured management of drilling hazards through a real-time risk-mitigation process. Additional engineers at the well site managed drilling parameters; continuously monitored cavings, cuttings, and drill fluids; and analyzed drilling mechanics and logging-while-drilling (LWD) log data for indications of impending problems. A Web-based real-time data-transfer system was used to deliver data to the onshore drilling and subsurface teams. These methods, combined with advanced communication techniques, enabled tight control of drilling parameters and trajectory and enhanced collaborative understanding within the multidisciplinary team. The third sidetrack was completed without incident, within time, and under budget.
A Systematic Approach to Predicting Liquid Loading in Gas Wells
Authors: Guo Boyun , Ghalambor Ali , Xu Chengcai
Published: April 2006

Loading up of liquids in wellbore has been recognized as one of the severe problems in gas production for many years. Accurate prediction of the problem is vitally important for taking timely measures to solve the problem. Although previous investigators have suggested several methods to predict the problem, results from these methods often show discrepancies. Also, these methods are not easy to use because of the difficulties with prediction of bottomhole pressure in multiphase flow. An accurate and easy-to-use method is highly desirable. This paper fills the gap.

Starting from Turner's analysis for prediction of the minimum gas velocity for liquid removal, the minimum kinetic energy of gas that is required to lift liquid droplets was determined in this study. In order to compare gas kinetic energy with the minimum required kinetic energy, a four-phase (gas, oil, water, and solid particles) flow model was developed for mist flow. Applying the minimum kinetic energy criterion to the four-phase flow model resulted in a closed-form analytical equation for predicting the minimum gas-flow rate.

The kinetic energy theory indicates that the controlling conditions for liquid drop removal in gas wells are bottomhole conditions rather than tophole conditions. Our case studies show that Turner's method with 20% adjustment still underestimates the minimum gas velocity for liquid removal, and the newly developed equation is more accurate than Turner's method. The new method is easier to use than other existing methods. This paper provides production engineers with a systematic approach to predicting the minimum gas-production rate for the continuous removal of water and oil from gas wells. Engineering charts are provided for two typical tubing sizes and wellhead pressures.
Factors Affecting the Increased Prevalence of Erectile Dysfunction in Greek Hypertensive Compared With Normotensive Subjects
Authors: Doumas Michael , Tsakiris Alexandros , Douma Stella , Grigorakis Alkiviadis , Papadopoulos Angelos , Hounta Athina , Tsiodras Sotirios , Dimitriou Dimitrios , Giamarellou Helen
Published: April 2006

ABSTRACT: Arterial hypertension is considered a risk factor for erectile dysfunction. The aim of the study was to evaluate the prevalence of erectile dysfunction in hypertensive compared with normotensive individuals of similar demographic characteristics in Greece. Furthermore, the effect of age, hypertension severity, hypertension duration, and antihypertension medication on erectile function of these subjects was investigated. The study population consisted of 634 consecutive young and middle‐aged men (31–65 years) that visited our outpatient clinic. From them, 358 patients had arterial hypertension and 276 were normotensive. Erectile dysfunction was evaluated with the International Index for Erectile Function questionnaire. Erectile dysfunction was found in 35.2% of patients with essential hypertension compared with 14.1% of normotensive subjects (χ2 = 35.92, P < .001). Patients with essential hypertension had more severe erectile dysfunction than their normotensive counterparts (χ2 = 17.1, P < .001). Hypertension duration, hypertension severity, antihypertension medication, and age were positively correlated with erectile dysfunction. The prevalence of erectile dysfunction is higher in patients with essential hypertension compared with normotensive subjects of similar demographic characteristics. Erectile dysfunction is related to age in both groups, whereas duration and severity of hypertension as well as antihypertension drugs affect erectile function of hypertensive patients. Erectile dysfunction affects patient quality of life, underlining the need for vigorous research of this condition and appropriate management.
Chiefs, subchiefs and local control: negotiations over land, struggles over meaning
Authors: Goheen Mitzi
Published: April 2006

Control over and access to land in Nso, Cameroon, has always depended on social identity. Control over land is a central symbol of leadership, both historically and today. Since the mid-1970s the Cameroonian state has instituted land ordinances and stressed privatisation and land titling, while Nso ideology has continued to emphasise access to land as a right of Nso citizenship. The contradictions set up by these two differing views are exacerbated by disputes between the Fon Nso and his sub-chiefs, in this case the Fon Nseh, over the right to control access to land. This prerogative, represented by the licence to collect taxes for the people farming on the land, is further complicated by the relationship of the two rulers and their constituents to the national state. Each Fon reinvents tradition by reinterpreting a series of historical events to buttress his claim, the Fon Nso stressing rights in people and the Fon Nseh stressing rights in territory by virtue of his ritual obligation to the ancestors residing there. This article examines the complex relationships and the distribution of power among these traditional rulers, the new elites and the national state.

Résumé

Le contrôle et l'accession à la terre à Nso, au Cameroun, a toujours dépendu de l'identité sociale. Le controle de la terre symbolise l'idée de chef, à la fois dans le passé et encore de nos jours. Depuis le milieu des années 1970, l'état camerounais a établi des arrêtes fonciers et renforce la privatisation et le droit foncier, alors que l'idéologie Nso a continué à accentuer l'accession à la terre comme un droit de citoyenneté Nso. Les contradictions produites par ces deux points de vues différents sont encore plus exacerbées par les désaccords entre le Fon Nso et ses sous-chefs, dans ce cas le Fon Nseh, sur le droit de controler l'accession à la terre. Ce privilege, representé par le droit de percevoir les impôts payables par les fermiers travaillant sur la terre, se complique encore davantage quant au rapport des deux chefs et de leurs partisans à l'état moderne. Chaque Fon réinvente la tradition en dormant une nouvelle interpretation à certains événement historiques pour étayer sa revendication: le Fon Nso met en valeur les droits du point de vue des gens, alors que le Fon Nseh renforce les droits dans la perspective du territoire en vertue de l'engagement rituel qu'il porte envers les ancêtres qui y résident. Cet article analyse les rélations complexes et la repartition du pouvoir parmi ces chefs traditionnels, les nouvelles élites et l'état moderne.
L'Apport de la teledetection dans l'etude des systemes agraires d'Afrique: l'exemple du Burkina Faso
Authors: Lambin Eric
Published: April 2006

Introduction

L'anthropologue, tout comme le géographe, a besoin, pour ses analyses, de collecter des informations sur les sociétés qu'il étudie. En particulier lorsqu'on étudie les sociétés rurales d'Afrique, la collecte de ces informations présente des difficultés. En effet, de nombreux obstacles physiques (l'inaccessibilité, l'inconfort) s'interposent entre l'observateur et l'objet de son étude. Par ailleurs, il existe une forte interaction entre l'observateur et son objet d'étude de telle sorte que ce dernier ne se dévoile pas dans toute son authenticité. Les nouvelles technologies de l'information offrent un outil nouveau et utile pour l'anthropologue à cet égard. Il s'agit des satellites d'observation des ressources terrestres. Ceux-ci permettent d'appréhender avec une grande clarté le milieu rural aménagé par les sociétés agraires. Un outil nouveau signifie également une information nouvelle: la télédétection permet une vision spatiale synoptique (qui embrasse en même temps un vaste territoire) et répétitive d'une région. De nouvelles méthodes d'analyse soumises à une approche écologique et systèmique des civilisations agraires doivent être recherchées pour l'utilisation optimale de cet outil.
Condition Swahili et identité politique
Authors: Constantin François
Published: April 2006

Opening Paragraph

Dans le très long et très riche débat sur la nature profonde de la condition swahili, tout ne semble pas avoir été dit. Pour d'obscures ou inavouables raisons, les politistes ont esquivé le problème alors même que les phénomenes d'identité collective, d'idéologie et de relations de pouvoir sont au cœur de leurs analyses. Pourtant, la question de la ‘swahilité’ constitue l'occasion idéale pour réveiller une attention assoupie par une tradition étatique lénifiante.
The Mountain People: some notes on the Ik of north-eastern Uganda
Authors: Heine Bernd
Published: April 2006

Opening Paragraph

Colin M. Turnbull's publications form virtually the only source available on Ik clture and society. His bookThe Mountain Peoplehas found wide distribution, far beyond anthropological circles. The problems it raises have been discussed in a number of reviews (see especially Beidelman, 1973; Spencer, 1973; Barth, 1974; Winteret al., 1975). Through the present article, I wish to show that there is an urgent need for a more comprehensive and less biased study of Ik culture md society.
From warrior to migrants: critical perspectives on early migrations among the Zarma of Niger
Authors: Painter Thomas M.
Published: April 2006

Opening Paragraph

In 1956 the Journal de la Société des Africanistes published a monograph-length paper by Jean Rouch entitled ‘Migrations au Ghana (Gold Coast: enquête 1953–1955)’ (Rouch, 1956). The paper was one of several publications during the 1950s and 1960s based on studies by Rouch and other researchers who participated in what was probably the largest study ever of West African migrations, financed by the Commission for Technical Cooperation in Africa South of the Sahara and the Scientific Council for Africa South of the Sahara (CCTA/CSA).
In search of personal mobility: changing interpersonal relations in two Bamileke chiefdoms, Cameroon
Authors: den Ouden Jan H. B.
Published: April 2006

Opening Paragraph

In this article I discuss the incorporation of the people of two Bamileke chiefdoms into wider economic and political systems. In doing this I will concentrate on the interactions and strategies of individuals. A number of issues will concern us: the types of relations of dependency within the chiefdoms and the possibilities for manipulating them to further individual economic, political and social mobility; the effects of the commercialisation of agriculture during both colonial and post-colonial periods; the opening up of areas outside the chiefdoms for trade and migration; the erosion of the chiefdom structure and its consequences for interpersonal relations and the possibilities for furthering individual and family interests. I will approach these problems mainly from the point of view of the changing patterns of authority and power relations.
Living with the past: the songs of the Herero in Botswana
Authors: Alnaes Kirsten
Published: April 2006

Introduction

‘I am in the Batawana's country,’ wrote the Herero chief Samuel Maharero to the British Magistrate in Tsau in Ngamiland on 28 September 1904. ‘I am writing to tell you that I have been fighting with the Germans in my country; the Germans were my friends; they made me suffer so much by the manner in which they troubled me, that I fought with them…’ (PRO CO 879/80). On the same date he wrote to the Tawana chief Sekgoma: ‘I tell you that I have fought with the German, they trouble me and killed my people, then I was angry about that. I have fought with them for 8 (eight) months, and I have no ammunition to-day, this is the reason why I came here…’ (PRO CO 879/86).
Law and order and the state in the Nyamwezi and Sukuma area of Tanzania
Authors: Abrahams Ray
Published: April 2006

Introduction

The Nyamwezi and Sukuma area of Tanzania covers about 50,000 square miles from Lake Victoria in the north to the southern edges of Tabora District. The area probably contains between 4 and 5 million people, about one fifth of the total Tanzanian mainland population. The two peoples speak regional variants of a single language—the name Sukuma simply meant ‘northerners’ originally—and they share many common social structural and cultural forms (Abrahams, 1967b).
Household strategies for adaptation and change: participation in Kenyan rural women’s associations
Authors: Thomas Barbara P.
Published: April 2006

Opening Paragraph

Recent literature on Third World households suggests that the household is a critical unit of analysis in decision-making and economic organisation for development (Smith, Wallerstein and Evers, 1984; Netting, Wilk and Arnould, 1984). Increasingly, this literature is addressing intra-household behaviour, the ways in which households relate to other institutions and the degree to which they are autonomous or embedded in more comprehensive social structures (Guyer and Peters, 1984; Folbre, 1985; Moock, 1986). Indeed, the household focus requires not only close examination of the household's internal dynamics, but also its external context. That context includes the physical setting, international as well as national political and economic structures, and the local political economic and social systems.
Children of tribulation: the need to heal and the means to heal war trauma
Authors: Reynolds Pamela
Published: April 2006

The Need for Healing

This article is about the unseen world of war—the unrecorded consequences for children of large-scale horror. There are two parts to it. The first is on the need for healing: it is an account of children's suffering during Zimbabwe's War of Liberation and their part in the fight for freedom. The second describes the means for healing: it examines how traditional healers (n'anga) provided opportunities through ritual for reconciliation and the soothing of individual trauma.
The cultural transformation of Western education in Sierra Leone
Authors: Bledsoe Caroline
Published: April 2006

The introduction of European schooling into West Africa in the late eighteenth century set in motion a profound cultural transformation. The Mende of Sierra Leone, the target of some of the earliest educational experiments in West Africa, began to reinterpret the Western ideals about the free dissemination of knowledge that were imposed on them. Focusing less onwhatis taught thanhowit is taught, the article shows that the Mende have transformed ideals about imparting knowl-edge according to local cultural tenets about secrecy and the control of knowledge. These tenets hold that, since valued knowledge is a key economic and political commodity, teachers, as proprietors of knowledge, deserve compensation for imparting it: a model of education manifested most strikingly in the region's famous secret societies. As was the case with more ‘traditional’ knowledge, the chief cultural idiom by which children acquire ‘civilised’ knowledge in school, and thus advance in the modern world, is through ‘buying’ or ‘earning’ blessings from those who teach them. By addressing ideologies of knowledge, power, and secrecy, the article sheds new interpretive light on the evolution of education in a country—indeed, among the very ethnic group—that comprised a keystone of nineteenth century British educational experiments in Africa.
Competition between foragers and food-producers on the Botletli River, Botswana
Authors: Cashdan Elizabeth
Published: April 2006

Opening Paragraph

The immigration of food-producing groups into areas occupied by hunters and gatherers must have been a common occurrence in prehistory. How were the hunter-gatherers affected by this? I describe here two groups of Kalahari Basarwa (‘Bushmen’), one living along the flood plain of the lower Botletli river, the other occupying the savanna a short distance away from the river. These two groups differed in subsistence and social organisation and were affected by immigrant herders and farmers in strikingly different ways. Today the Basarwa of the flood plain are wealthy cattle owners, whereas those of the savanna are poor and have few or no cattle. How and why did the two groups respond so differently to the same competitive threat?
‘For the use and common benefit of all Nigerians’: consequences of the 1978 land nationalization
Authors: Francis Paul
Published: April 2006

Opening Paragraph

On 29 March 1978 the Federal Military Government of Nigeria promulgated the Land Use Decree, which, with immediate effect, vested all land in the territory of each state of the Federation in the Governor of that state. The land was to be ‘held in trust and administered for the use and common benefit of all Nigerians’ in accordance with the provisions of the Decree. This paper considers the origins and effects of this policy of land nationalization.
Illness, therapy, and change in Ethiopian possession cults
Authors: Vecchiato Norbert L.
Published: April 2006

This article examines patterns of continuity and change in spirit possession phenomena among the Sidamo of southern Ethiopia. Traditional possession rituals appear to be losing cultural relevance, owing to the increasing popularity of possession and exorcistic healing enacted within the ritual context of independent religious movements. Such movements emerged in the region as a response to widespread conversion to Christianity and Islam in the 1950sand 1960s. Patterns of possession healing in the new cults are analysed in relation to the prevailing holistic definition of health and the role attributed to supernatural agents i n illness aetiology. While outlining points of convergence and divergence in the recodification of rituals, this article highlights their therapeutic objectives and the centrality of healing in the newly emerged cults. It is argued that the political and sex antagonism model proposed by ‘deprivation theories’ is inadequate to explain the changing modalities of spirit possession and its persistence on the African scene. Independent healing movements should be recognised as an important health resource where rural and urban Africans seek relief from a wide range of organic and mental illnesses, personal misfortunes, and stressful life situations.
The barracuda's tale: trawlers, the informal sector and a state of classificatory disorder off the Nigerian coast
Authors: Klein Axel
Published: April 2006

The expansion of Nigeria's artisanal fisheries has been a rare economic success story during the 1980s. Without assistance from government agencies the canoe fishermen, many of them Ghanaian migrants, have responded successfully to the opportunities offered by the Lagos market. In recent years declining fish stocks and competition from trawlers have forced shore-based fishermen to adapt their operations to changing circumstances. In describing a number of such responses the article tackles a number of wider themes in economic anthropology and African studies. Contrasting the opposition and co-operation of industrial and artisanal fisheries throws an interesting light on the informal sector debates, while the role played by the marine police and the navy feeds into the discussion on the African state.
Defining Akyemfo: the construction of citizenship in Akyem Abuakwa, Ghana, 1700–1939
Authors: Rathbone Richard
Published: April 2006

By the early twentieth century the ruler of the historic Akan kingdom of Akyem Abuakwa in what is now the Republic of Ghana and his subjects confronted one another over issues of identity and allegiance. The evidence suggests that not only was this debate unprecedented but also that its language was novel. Such divisive issues were forced upon them by a tranche of new factors. These included the ownership of, or rights to, land as farms acquired increasing cash value in the wake of the success of cocoa cultivation. No less important in a jural setting dominated by the institutions of indirect rule was the issue of which chiefly jurisdiction applied to individual communities and even families in a kingdom with a historically varied ethnic population. The article shows how the king gradually elaborated both an ideology and a corpus of regulation which attempted to define citizenship and stranger status. The king and his council's organising principle idealised an ethnically homogeneous state. Many sections of the kingdom's population strongly contested the idea. They did so in part because this agenda potentially disempowered long-settled communities while granting new privileges to those close to the centre of ‘traditional’ power.
Female over male or left over right: solving a classificatory puzzle among the OvaHimba
Authors: Crandall David P.
Published: April 2006

This article puts forward a resolution to a curious circumstance, namely, why the left, and not the right, appears to be pre-eminent among the Himba. Himba arrange gendered, domestic and ritual space, their own bodies in ritual contexts and, to an extent, time strongly in favour of the left. The fact that in their language ‘left’ connotes weakness while ‘right’ connotes strength adds to the puzzle. It is argued that, to understand this apparent contradiction of the near-universal classificatory ascendancy of right over left, one must assess the Himba dual symbolic system while drawing upon the principle of symbolic parallax which allows a single referent, in this case the sacred ancestral fire, to be viewed from differing spatial perspectives. By following this procedure the puzzle is resolved, as the human direction from which the primary referent is viewed is merely the mirror image of a transcendant view.
Marital instability in a rural population in south-west Uganda: implications for the spread of HIV-1 infection
Authors: Nabaitu Januario , Bachengana Cissy , Seeley Janet
Published: April 2006

The aim of this study was to examine people's beliefs about the causes of marital instability in a rural population cohort in south-west Uganda. Results from a baseline survey of HFV-1 infection in the cohort of over 4,000 adults (over 12 years old) showed a twofold increase in risk of infection in divorced or separated persons when compared with those who are married. A purposive sample of 134 respondents (seventy-two males, sixty-two females) selected to represent different ages, religions and marital status were asked in semi-structured interviews to comment on the reasons for continuing marital instability in their community. The most common reasons suggested for marital instability were sexual dissatisfaction, infertility, alcoholism and mobility. Interviewees stated that men and women would be more likely to stay with someone who satisfied them sexually. It was reported that infertility, particularly of the woman, would lead a couple to separate. Alcoholism was said to lead to neglect of family responsibilities and decreased sexual inhibitions, while occupational mobility was a common cause of infidelity. HIV infection was not mentioned as a direct cause of separation, but a small independent study revealed that seven out often couples separated on learning of a positive HIV test result of one or both partners. Marital instability is not uncommon in this population; there is evidence that HFV infection is making the situation worse.
Family, marriage and divorce in a Hausa community: a sociological model
Authors: Solivetti Luigi M.
Published: April 2006

The aim of this article is to show how a ‘traditional’ society may produce a household system in which the structural tensions are no less intense than in the Western world. Muslim Hausa society (in northern Nigeria) has one of the highest rates of divorce (and remarriage) in the world. An explanation is sought here in terms of the economic and organisational requirements of a subsistence farming system that is always potentially short of labour. Divorce is a solution to otherwise unacceptable pressures, particularly on young women, in a society that requires them to be subordinate and marginal within the extended family. The data presented here were collected between 1979 and 1989 in the Niger valley of Sokoto State in northern Nigeria.
Mamprusi witchcraft, subversion and changing gender relations
Authors: Drucker-Brown Susan
Published: April 2006

In the pre-colonial Mamprusi kingdom female witches were either executed after sentencing in the king's court, or segregated in a special section of a major market town where they received medicine to neutralise their witchcraft. This treatment of witches is a manifestation of the centralising process at work in the kingdom, and also exemplifies the division of ritual labour characteristic of the polity. Recent changes in the constitution of the witches' village have been accompanied by new Mamprusi conceptions of witchcraft, drawing on a long-standing belief in the power of women to subvert the social order. Radical changes in national political and economic conditions, and local changes in the division of labour, are threatening the idealised norms of Mamprusi gender relations. Mamprusi witch-hunting emerges as an attempt to control women, who are perceived as a source of these wider disorders.
Christianity, modernity and the weight of tradition in the life ofAsanteheneAgyeman Prempeh I,c.1888–1931
Authors: Akyeampong Emmanuel
Published: April 2006

Much of what has been written on Asantehene Agyeman Prempeh I (1888-1931) focuses on his career as the king of Asante in the context of British colonisation. This article attempts to shed some light on Prempeh's personal life, and his engagement with Christianity and modernity. The article defines modernity and conversion in the Asante context, and examines Prempeh's pioneering efforts to fuse Asante tradition with modernity. The endeavour had profound consequences for Prempeh and Asante. The article is a micro-study of the operation of global cultural forces in a non-Western context.
Aesthetic strategies: the politics of a royal ritual
Authors: Gilbert Michelle
Published: April 2006

The article explores both the meaning of Odwira, the royal ritual which annually cleanses the community of pollution, and the way the rite is used to negotiate the shifting configurations of power in Akuropon and the kingdom of Akuapem. In a small society where consensus is required in public and conflict is covert, where kings formerly had the power to reduce opponents to slavery and still today can deny them a position and a home, opposition must be circumspect. Rituals and symbols are good for making a political statement, since an in-built ambiguity makes them a safe medium for political aggression. For this reason, although the Odwira ritual of purification is thought to be unchanging in its performance and symbolic structure, i n practice the community's volatile politics are also reflected in the ad hoc modifications made each year to the lengthy ceremonial process.
Money and respect: the changing value of old age in rural Ghana
Authors: van der Geest Sjaak
Published: April 2006

This article describes the position of elderly people from the perspective of money anddiscusses the meaning of money from the perspective of elderly people. Anthropological research was carried out in 1994, 1995 and 1996 in a rural Kwahu community in southern Ghana. It consisted mainly of long conversations with elderly people and their relatives. Money is a core symbol in daily life by which people measure the value of their relationships. It is not used to keep people at bay but rather to establish and maintain social bonds and to secure care in old age. Having money engenders respect, as it is a sign of a successful life, while lack of money discloses failure and shame. Giving money is a way of ‘paying’ respect and shows affection and care for the elderly.
Male praise-singers in Accra: in the company of women
Authors: Pellow Deborah
Published: April 2006

In 1957 M. G. Smith published a seminal paper on the role of the male praise-singer, themaroki, among Northern Nigeria's Muslim Hausa. My paper explores the role of themarokiin the diaspora community of Sabon Zongo in Accra. While Accra'szongocommunities are considerably diluted in their Islamic orthodoxy, they are nonetheless distinctly Islamic in tone, witness the mosques, Qurʼānic schools, flowing robes and diaphanous prayer veils, and a general cultural orientation that is strongly influenced by the Hausa and distinct from Christian southern Ghana. Among the Hausa, and thosezongoinstitutions particularly affected by Hausa custom, there is also a vestigial separation between the worlds of men and women. This article considers themarokias an ungendered actor. It suggests that, through his attendance at Hausa andzongowomen's occasions, he has become their client, regards them as his patrons and conjoins their world with that of men.