bluuebunny/crossref_metadata_2025 huggingface dataset:
Haynesville Shale Development Program – From Vertical to Horizontal
Authors: Abou-Sayed I. S. , Sorrell M. A. , Foster R. A. , Atwood E. L. , Youngblood D. R.
Published: September 2011

The recently discovered Haynesville Shale is one of the largest natural gas fields in the world. It is a high – temperature, high – pressure (HTHP), aerially extensive basin gas with true vertical depths (TVD) ranging from 10,000 – 14,000 ft; temperatures of 300 – 350+ deg F; and pore pressures exceeding 10,000 psi. It represents an engineering challenge unlike other popular shale reservoirs including the Barnett, Fayetteville, and Bakken shales.

In March 2008, EXCO started an aggressive development program in the Haynesville Shale reservoir on its East Texas/North Louisiana (ETX/NLA) acreage.

The program had a six-month window to select a landing zone and the appropriate drilling and completion techniques. Those techniques were then refined and applied to the horizontal well development.

The program included drilling six (6) vertical wells covering over 150 square miles to understand the reservoir rocks’ fracture properties and flow characteristics. It included whole cores; shale logging suites; hydraulic fracture design, operations, and diagnostics; chemical and radioactive tracers; flow-back characterization; diagnostic pressure testing and production evaluation.

At the conclusion of the vertical appraisal phase, EXCO spud its first horizontal Haynesville well in DeSoto Parish by drilling the Oden Heirs 30-6H well. The well's initial potential exceeded over 22 MMCFD @ 7,800 psi. This success encouraged the company to continue the development program resulting in 16 of the top 25 wells in the basin.

This paper outlines the program and the steps taken to achieve this accomplishment.
Well Performance Modeling in Eagle Ford Shale Oil Reservoir
Authors: Wang Jianwei , Liu Yang
Published: September 2011

Producing oil from shale oil reservoirs has gained attestations over the past several years. To efficiently and economically develop shale oil reservoirs, the impacts of hydraulic fracture parameters, hydraulic fracture induced complex natural fracture system, and rock characteristics to well performance need to be clearly understood. Numerical simulation based methods provided a better way over other conventional methods for modeling well performance in shale gas reservoirs, however it is still not clear if shale oil reservoir can be modeled using the same ways. We developed a simplified, coarse, dual porosity model to quick evaluate the effectiveness of stimulation treatment and understand shale oil production mechanism. Simulation results of a fine-grid reference model were compared with the simplified model to validate the new methodology. The simplified model greatly decreases simulation time and provides accurate results.

We applied this methodology to Eagle Ford shale oil wells. Historical oil, water, and gas production were matched for selected vertical wells. Reservoir and enhanced zone parameters were obtained after history matching, including OOIP, EUR, porosity and permeability of the matrix and natural fracture system, as well as half length, width, and permeability of the complex fracture network. Sensitivity analyses for horizontal wells then were conducted to quantify the impact of the reservoir characteristics and enhanced zone parameters, including net pay thickness, matrix porosity, permeability of the matrix and natural fracture systems, natural fracture spacing, half length, width, and permeability of the complex fracture network.

The simulation results indicate that the natural fractures permeability has the greatest impact on estimated ultimate oil recovery (EUR). Hydrocarbon pore volume (pay thickness and porosity) have the second greatest impact on EUR. The variability of matrix permeability has little effect on the oil recovery. The simulation results provided insights into effective stimulation designs and flow mechanism for shale oil reservoirs.
Advancements in Shale Gas Production Forecasting – A Marcellus Case Study
Authors: Thompson J. M. , M'Angha Viannet Okouma , Anderson D. M.
Published: September 2011

Arps Decline Curve Analysis (DCA) has been the standard for evaluating expected ultimate recovery (EUR) in oil and gas wells since the 1950's. Although this empirical method has served the conventional petroleum industry well, its misapplication to wells in ultra-low permeability plays, most notably shale, often yields ambiguous results due to invalid assumptions. Depending on the application of DCA, these forecasts, with constant hyperbolic decline exponent (‘b-value’) assumptions, have proven to be either overly optimistic or overly pessimistic. The applicability of the Arps method is limited to wells exhibiting boundary dominated flow. However shale wells exhibit transient flow for years, making them unsuitable candidates for the conventional approach of DCA. With the industry now focused on shale, new tools are required to help reduce uncertainty in well forecasts.

This paper presents a two-part study on the forecasting of shale gas well production. Part one utilizes a recently developed trilinear flow model (Ozkan et al. 2009) to improve forecast reliability while preserving simplicity for practical application. It is designed to account for 1) considerations of multi-fractured horizontal wells (MFHW), 2) improved localized effective permeability within the stimulated reservoir volume (SRV), 3) regional permeability contributions to the SRV and, 4) potential contributions of adsorbed gas to expected ultimate recovery. A workflow using this model is proposed and exemplified using production data from two gas wells from the Marcellus Shale (North-East Pennsylvania).

Although analytical models provide a deeper understanding of shale gas reservoirs as well as more reliable forecasting capability, Arps decline curves are, and will continue to be, the language of the reserves evaluation. That is why it is useful to understand the dynamic behavior of the decline exponent resulting from flow regime transitions during the transient period. Part two of this paper highlights an important consideration in the application of DCA to shale: the effect of desorption on the b-value. It will be shown that when desorption is invoked, the b-value will increase. This difference has been quantified for a MFHW in the Marcellus using a Langmuir adsorption isotherm representative of the region.
Consideration Factors in Defining an Effective Scale Management Strategy During Early Stages of Field Development Planning
Authors: Akuanyionwu Obinna , Wahid Fazrie
Published: September 2011

Developing a cost-effective scale management strategy as early as possible during field development planning is imperative to allow informed decision making. In the past, strategy selection was commonly based on static scaling risk assessment. However, the trend over the years has shifted to incorporate dynamic aspects, notably in-situ scale precipitation in a time lapse manner and coupling this with scaling risk assessments. More recently, streamline simulation techniques have been applied to support the prediction of scale precipitation in the reservoir and consequent in-situ stripping of scaling ions. It remains pertinent to extend the use of these dynamic tools to properly assess the impact of reservoir scaling reactions on scale management economics and the subsequent adoption of an optimum strategy.

A robust and systematic approach has been developed to combine the use of dynamic models in scaling risk assessment with envisaged production improvement processes and integration of disciplines in the decision analysis process. Reservoir scaling reactions are modeled using streamline simulation. Examinations have been extended to cover the impact of in-situ scale precipitation, taking into account changes in drainage radius in the presence of hydraulic fractures and different sandface completions. Emphasis is also placed on conducting analyses to address field complexities ranging from a variety of potential field development concepts, injection water alternatives, and drainage and completion options to uncertainties in formation water composition.

Workflows developed on a North Sea green field development are described, including results from analog/synthetic datasets as examples for this paper. Our work indicates that both in-situ ion stripping and drainage patterns significantly influence chemical requirements and treatment frequencies for squeeze treatments following in-situ scale deposition. Based on this information, comparative scale management costs are developed to help select the most appropriate scale management option. Finally, we highlight limitations in current industry tools and workflows and what can be done to reduce uncertainties during the development of a scale management strategy.
Sourceless LWD Service Provides Unique Petrophysical Measurements for the First Time in Offshore Environment: A Case Study from Libya
Authors: Meunier A. , Gonzalez-Munoz J. M. , Suarez Jaime
Published: September 2011

The continuous increase in demand for hydrocarbon resources has pushed the oil industry to look for additional recoverable resources in increasingly challenging environments. With new prospects, oil companies have to face new technical challenges everyday due to these conditions as well as stricter environmental and safety rules.

Offshore Libya is one of these challenging environments where drilling is high risk and where, for health safety and environmental (HSE) reasons, avoiding using radioactive materials in drilling and logging represents a great advantage by mitigating possible risks and costs. In order to overcome these new technical challenges and reduce cost, companies have to constantly evaluate new technology.

An advanced logging-while-drilling (LWD) platform that does not use a radioactive source provided a fully integrated advanced petrophysical evaluation capability, as well as a complete set of measurements to optimize drilling in a well in offshore Libya. To overcome environmental and safety constraints, the sourceless configuration provided a unique answer for formation evaluation in high risk drilling operations in offshore environments. A fully integrated real-time petrophysical analysis of data acquired while drilling thereby significantly reduced the need for additional measurements. This technology allows fulfillment of operational objectives by significantly decreasing the exposure to drilling risks and stuck pipe. This reduced

the time and cost required to properly characterize the reservoir and accommodate the strict regulations controlling radioactive material handling, without compromising the data completeness and quality.

The conventional EcoScope* technology has been used all over the world in offshore environment (especially in the North Sea). However, it is the first time the EcoScope* service has been deployed in an offshore drilling environment in its sourceless configuration.
High Speed Acoustic Telemetry Network Enables Real-Time Along String Measurements, Greatly Reducing Drilling Risk
Authors: Reeves M. E. , Camwell P. L. , McRory J.
Published: September 2011

A unique multi-node acoustic telemetry network capable of transmitting data at over 30 bits per second has been developed and successfully deployed in drilling applications.

This paper details the lessons learned and value derived from early use of the acoustic telemetry network while drilling medium radius build sections of multiple horizontal wells. Particular focus is given to discussion of overall network reliability, ease of well-site implementation and delivery of pressure data from multiple along-string measurement locations with or without fluid circulation.

Low latency, high-speed, real-time transmission of pressure data (from near the bit and other key locations along the borehole) allows highly accurate, potentially automated management of annular pressure to avoid unintentional formation fracture or fluid influx during drilling and non-drilling activities. This data can also be utilized to understand hole cleaning effectiveness in different sections of a well, allowing focused corrective action to be taken at the first sign of cuttings build-up, potentially avoiding costly stuck pipe incidents. In addition, continuous data transmission without the need for fluid circulation enables significant risk reduction when addressing well control incidents.

Highly reliable tools placed up to 2,500 meters apart establish the acoustic telemetry network within existing drill strings and in conjunction with all bottom hole assembly components. It is virtually transparent to all rig operations and, as a result, significantly decreases the implementation time and cost when compared to along string measurement solutions delivered by wired drill string technology.

This is the first publication of information from such field deployments and the first display of multi-node pressure data delivered via acoustic telemetry while drilling.
Re-assessment of Reservoir Dynamic Behaviour to Assist the Fourth Drilling Campaign in Mature, Geologically Complex North Sea Field
Authors: Valko I. , Moreau L.-P. , Coombes T. , Cooper R. , Troussaut X.
Published: September 2011

The Dunbar Field (UKCS, Block 3/14a), operated by Total E&P UK, is situated on an intermediate terrace between the East Shetland Platform and the Viking Graben and characterised by a series of pre-Cretaceous and structurally aligned tilted fault blocks. The principal hydrocarbon accumulations are contained in the Middle Jurassic Brent Group and younger Upper Jurassic Heather Sands.

Internally, the field is compartmentalised by a number of N-S faults and a secondary alignment of NE-SW faults which cross cut and often offset the main N-S faults. The larger scale faults down throw to the east and subdivide the field into four main areas; the West Flank, Central Panel and Frontal Panel with an uplifted Horst (Triassic) Panel in the south. Each of these panels has specific reservoir and fluid characteristics.

The Central and Frontal panels have a substantial production history of 15 years. The field is in steep decline with high water cut in water flooded areas, and extremely low pressure in compartments produced by natural depletion. A better understanding of recovery from the main flow units is essential for estimation of drainage volume, optimisation of water injection pattern and infill well placement/completion.

The ability to better define the size of the connected volumes through improved fault identification (Seismic PSDM3D Reprocessing) along with an improved understanding of the permeability field (sedimentological, petrographic, XRD, SEM, SrRSA, DST analysis & simulation studies) has been key in assessing Dunbar’s future potential. An intensive data acquisition campaign has been integrated in a comprehensive dynamic synthesis leading to a reservoir model history match that has improved our understanding of the field.

This paper describes the multidisciplinary team work leading to an improved understanding of the recovery efficiency and reservoir connectivity leading to a further drilling campaign.
Heavy Oil Offshore UK: Recommended Mariner Reservoir Development Strategy
Authors: Berg Eirik A , Reksten Kari , Scott Anthony Stephen , Ibatullin Tair , Møllerstad Hilde , Aasum Yngve , Julseth Lillian
Published: September 2011

The Mariner field - license 9/11 in the UK – was discovered in 1981 and is situated on the East Shetland platform. Mariner consists of two tertiary reservoir intervals of unconsolidated sand at depths between 1200 and 1500 mMSL. The deeper Maureen reservoir consists of stacked non-channelized sheet-like sand lobes deposited in a shelf to slope setting. The Maureen oil water contact (OWC) is stepping considerably and is shallower to the west. The Heimdal reservoir consists of deep-marine slope-channel sands within the mudstone-rich Lista interval, ranging in thickness from a few meters up to 40 m. The reservoir is heavily remobilised. The Heimdal OWC is uncertain with variable ODT (Oil Down To) observations and anticipated perched water. The total Mariner oil reserves are estimated to app. 400 MMBO (Million Barrels). The Maureen reservoir has 67 cp oil (14°API) in a 0–40 m oil column and a large bottom aquifer. The Heimdal reservoir contains two thirds of the reserves and has 508 cp oil (12 API).

Steady State SCAL studies indicate that Krw may be viscosity dependent. The Heimdal reservoir is planned to be developed using an inverted 9-spot well pattern due to uncertainty in mapping of the reservoir. The Maureen reservoir will be developed with horizontal wells. As the recovery factors are only 22%, Enhanced Oil Recovery using polymer is investigated as an upside to be matured towards production start. IOR through use of down-hole inflow control devises is progressed in a technical qualification program. OBC (Ocean Bottom Cable) data will be acquired to improve the mapping of the Heimdal reservoir.
Selection of Low Carbon Field Development Plans based on Lifecycle Energy Modeling
Authors: Mallinson Theo
Published: September 2011

Lifecycle energy modeling can be used as a primary design input during early project development. This requires a life of field facility model adapted to early concept design which allows operational costs and revenue collection to be considered against capital cost impact. Significant overall project savings can be discovered with this analysis even in cases where CAPEX impact is unfavorable. A design model based on a production depletion curve is used to set facility capacity requirements and to allow calculation of operational data such as yearly production achieved, fuel gas usage, carbon emissions value, and deferred production due to downtime. Production concepts can then be subjected to a quantitative analysis of external influences, such as effect of carbon emissions cost on project economics. A sensitivity case is developed using a production concept based on an all electric facility with major users (gas injection compressors and water injection pumps) employing variable frequency electric motors. Calculated carbon emissions, fuel gas usage, and expected availability for this case are compared against a base case utilizing discrete gas turbine drives. These lifecycle cost methods and analyses can supplement the conventional CAPEX focus during initial design phases of onshore and offshore facilities, a period in which some of the most important facility design decisions are made.
Fluid Composition Equilibrium; a Proxy for Reservoir Connectivity
Authors: Pfeiffer Thomas , Reza Zulfiquar , Schechter David S. , McCain William D. , Mullins Oliver C.
Published: September 2011

Assessing reservoir connectivity during the earliest stages of reservoir evaluation is highly desirable for successful field development. Nevertheless, it has long been problematic to assess reservoir connectivity prior to production. Recently, downhole fluid analysis has enabled facile assessment of fluid compositional gradients vertically and latterally. Using equations of state, the extent of fluid compositional equilibrium can be established. Only a process that stretches across the entire age of the reservoir is likely to capture geologic events that cause compartmentalization. Fluid composition equilibration requires mixing of the entire content of the reservoir which occurs only on the geologic time scale. Restrictive flow barriers are not compatible with thorough mixing of fluids throughout the reservoir. Fluid composition equilibration provides a tight constraint to test connectivity.

In this paper, the time constants for fluid composition equilibration are evaluated in numerical simulations. Equilibration processes are simulated in a simplified model over geologic timescales at isothermal conditions where diffusion and gravity are the active mechanisms. A variety of initial conditions and reservoir fluid types are considered. The effect of barriers on the equilibration time is investigated for single and multiple barriers. The results are compared with analytical calculations. Longer equilibration times correspond to tighter constraints on connectivity.

This work shows the progression of compositional gradients over geologic time until all components have reached zero mass flux. It investigates the foundation of connectivity studies that rely on fluid composition.

Determination of fluid equilibrium should become part of the standard procedure for reservoir connectivity evaluation.
Integrity of High Pressure Relief Systems
Authors: Smeulers J. P. , Hageraats-Ponomareva S. V.
Published: September 2011

Pressure relief systems are applied in various installations in the Oil & Gas industry. Especially in upstream applications, the importance of relief systems cannot be underestimated, because failure can lead to release of hydrocarbons to the environment. The upstream production facilities (e.g. subsea production systems, assets on a production platform) are usually protected from overpressurarisation by a HIPPS which shuts in the well when local pressure levels exceed a certain threshold. In addition to this, a pressure relief line is often installed as a last safety barrier when shut-in of the well by means of the HIPPS fails. Especially if gas is produced from a high pressure high temperature reservoir (HPHT), the relief system should be designed such that it can sustain the extreme flow conditions that occur when it is activated.

Serious incidents with failing relief lines in the past have raised the attention for the integrity of relief systems and lead to requests for integrity evaluation of newly designed relief systems. Integrity evaluations should address the following dynamic flow phenomena: 1) the generation of shock waves when the relief valve is opened instantly; 2) the occurrence of two-phase flow in the relief line and the corresponding formation of slugs; 3) acoustic fatigue, which is the result of extremely high sound levels in the line generated by the expansion of gas through the relief valve; and 4) possible relief valve instability. This paper addresses how aforementioned phenomena can potentially affect the mechanical integrity of pressure relief systems. A case study of a typical pressure relief system is used to assess the dynamic flow phenomena and how these relate to the mechanical integrity of the relief system. The methods that are discussed in this paper can be directly applied to such mechanical integrity analyses.
Benefits and Limitations of Assisted History Matching
Authors: Cancelliere M. , Verga F. , Viberti D.
Published: September 2011

Some years ago, a new methodology called automatic history matching was approached by the scientific community. The idea consisted in treating history matching as an optimization process, i.e. defining a cost function representative of the discrepancy between measured (real) and simulated data, and in minimizing the cost function. The minimization of the cost function can be obtained by applying a suitable optimization algorithm. Optimization and non-linear programming were not new methodologies in the field of applied mathematics. However, the selection of the most adequate optimization algorithm among those available in the technical literature is not trivial, and the number of independent variables involved in complex reservoir simulation does not make the solution of the optimization problem a standard procedure. In fact, the main criticalities of a history matching process change for each analyzed reservoir. As a consequence, the identification of an optimization methodology appropriate for a wide variety of reservoirs is quite impossible. Therefore, automatic history matching remains a dream and, more realistically, assisted history matching can be the target.

The concept of assisted history matching is that reservoir engineers are still in charge of reservoir model calibration, but they can rely on reliable optimization tools to better explore the parameter space and to speed up the convergence to one or more solutions.

The aim of this paper consists in discussing benefits, limitations and drawbacks of assisted history matching by applying new techniques, based on multi objective optimization and heuristic strategies. Attention is focused on the possibility offered by these methodologies of obtaining a number of calibrated reservoir models. Each of these models can then be used for field performance prediction so as to obtain a representative evaluation of the risks associated to any reservoir development scenario.
12 Days Under The Ice With An AUV
Authors: Ferguson James , Laframboise Jean-Marc , Mills Richard
Published: September 2011

In March and April 2010, an ISE Explorer Autonomous Underwater Vehicle (AUV), built for Natural Resources Canada (NRCan), was deployed to Canada’s high Arctic. Its mission was to undertake under-ice bathymetric surveys in support of Canada’s submission to establish the outer limits of its continental shelf under the United Nations Convention on the Law of the Sea (UNCLOS). During this deployment several under-ice records were broken and several new technologies were demonstrated.

NRCan’s AUV is an ISE Explorer class vehicle, with several innovative additions to make it suitable for arctic survey work. Most notable are a 4000 m depth rated variable ballast system, a 1500 Hz long-range homing system, and under-ice charging and data transfer capabilities. A Short-Range Localization (SRL) system was also developed for close range positioning. The homing and SRL systems were developed by Canadian defense scientists and engineers at DRDC (Defence Research and Development Canada).

The Explorer’s range was extended to approximately 450 km by adding a hull section to accommodate extra batteries. The scientific payload onboard included a Seabird SBE49 Conductivity-Temperature-Depth (CTD) sensor, Knudsen singlebeam echosounder, and a Kongsberg Simrad EM2000 multibeam echosounder. In order to optimize battery endurance, the plan was to only turn on the EM2000 at strategic locations (i.e. potential sea mounts) along the mission path.

The Main Camp near Borden Island (78°14’N, 112°39’W) was the launch site for the AUV. It was launched from an 8 m by 3 m ice hole, cut through 2 – 3 m thick ice. After several test dives, the first mission was a transit to a Remote Camp, 320 km to the northwest. The AUV autonomously homed into the Remote Camp and was secured with the help of a small remotely operated vehicle (ROV). Without being removed from the water, it was charged and survey data was downloaded, all through a 1.3 m by 2 m ice hole. Subsequently, a second survey mission was undertaken in a region known as the Sever Spur (~79°N, 115°W), which returned back to the Remote Camp. Finally, it embarked on a return transit mission to the Main Camp for recovery. The AUV spent 10 days under ice before being successfully recovered. In total, close to 1000 km of under-ice survey was accomplished between the 3 missions. The AUV reached depths of 3160 m and transited at an average speed of 1.5 m/s at an altitude of 130 m above the seabed. From operating entirely under ice, to surveying in such a challenging environment, to the distances and objectives, this is an historic milestone in AUV and polar science. ISE, DRDC and NRCan are now preparing for a 2011 deployment to collect additional arctic survey data.
Buoyancy Technology Used Effectively in Casing-Running Operations to Extend Lateral Step-Out: Multiple Case Histories Detail Application Risks, Successes, and Improved Operation Procedures
Authors: Rogers Hank , Ryen Daniel , Sparks Dale
Published: September 2011

Operators today face an ever-increasing demand for locating commercial reserves and producing those reserves with an emphasis on exploration and development costs. In addition to basic financial pressures, operators also strive to reduce the environmental impact of well-construction and production operations. Extended-reach drilling technology allows operators to reach recoverable reserves that were previously unreachable. Specifically, extended-reach drilling from a multipad wellsite allows significant portions of the well-construction costs to be distributed throughout multiple wells rather than being carried by an individual wellbore. Also, the capability to drill multiple wells from a single pad reduces the environmental impact of the drilling operation.

Extending the wellbore reach from a given pad depends on the location of the target formation. Depth, horizontal distance, and production type significantly affect the type of drilling program, as well as the casing-running operation. Casing flotation is a proven technology that has been deployed in multiple fields around the world to extend the attainable lateral reach of the casing-running operation. In many wells where flotation is required, the common limiting factor that determines the maximum step out that can be achieved is based on available hook load or weight in the near-vertical section of the well. However, when smaller casing strings are used, the limiting factor is not available weight, but rather the buckling limits of the casing. In some cases, slackoff loads with small casing strings cause helical buckling and lockup of the casing before reaching total depth (TD).

This paper documents the use of flotation technology in several wells where buckling limits and subsequent casing lockup was averted to allow successful casing-running operations to be performed without the requirement of costly premium torque-shouldered connections. Additionally, the paper presents improved processes used successfully that significantly increased operational efficiencies before cementing operations. Detailed prejob planning and computer simulations are provided to demonstrate the limits without casing flotation and the stepout achieved with casing flotation.
Employment Precariousness in Spain: Prevalence, Social Distribution, and Population-Attributable Risk Percent of Poor Mental Health
Authors: Vives Alejandra , Vanroelen Christophe , Amable Marcelo , Ferrer Montserrat , Moncada Salvador , Llorens Clara , Muntaner Carles , Benavides Fernando G. , Benach Joan
Published: September 2011

As a consequence of labor market flexibilization, nonstandard employment has expanded and standard employment has declined. In many cases, these transformations are best described as an evolution toward precarious employment, which is considered a major determinant of health and health inequalities. Using the Employment Precariousness Scale (EPRES), this study aims to determine the prevalence of precarious employment in the waged and salaried workforce in Spain, to describe its distribution across social groups defined by occupational class, gender, age, and immigrant status, and to estimate the proportion of cases of poor mental health potentially attributable to employment precariousness. Data are from the Psychosocial Work Environment Survey conducted in 2004–5 on a representative sample of the Spanish workforce. Findings indicate a high prevalence of employment precariousness, affecting nearly 6.5 million workers, with almost 900,000 of them exposed to high precariousness. These estimates are higher than the proportion of fixed-term employment reported in regular statistical sources but may today be an underestimation, given the current economic crisis. Additionally, a significant proportion of cases of poor mental health are potentially attributable to employment precariousness. Both the proportion of cases of poor mental health attributable to and the prevalence of employment precariousness were highly unequally distributed across the study sample, indicating that this may be a significant contributor to social inequalities in mental health.
The Impact of Public Employment on Health and Health Inequalities: Evidence from China
Authors: Zhang Wei
Published: September 2011

Because the public and private sectors often operate with different goals, individuals employed by the two sectors may receive different levels of welfare. This can potentially lead to different health status. As such, employment sector offers an important perspective for understanding labor market outcomes. Using micro-level data from a recent Chinese household survey, this study empirically evaluated the impact of employment sector on health and within-sector health inequalities. It found that public sector employment generated better health outcomes than private sector employment, controlling for individual characteristics. The provision of more job security explained an important part of the association between public sector employment and better health. The study also found less health inequality by social class within the public sector. These findings suggest that policymakers should think critically about the “conventional wisdom” that private ownership is almost always superior, and should adjust their labor market policies accordingly.
Social Health Insurance: To Each According to His Needs; From Each According to His Means—but What Might That Mean?
Authors: Akazili James , Mooney Gavin
Published: September 2011

Despite the substantial literature on the financing and benefit incidence of social health insurance, the principles underlying such schemes are little debated. This article examines one of these key principles: to each according to his needs; from each according to his means. The authors discuss both sides of this principle at a conceptual level. On the needs side, they examine the issue of vertical equity. The approach of “communitarian claims” is proposed, both for eliciting the components of need and for determining the relative weights to be attached to the vertical dimensions of equity in health service delivery. On the means side, the authors also look to communitarian claims to assist in determining who should bear what burden in paying for social health insurance. They argue that with respect to the concept of “from each according to his means,” it is useful to incorporate an element of willingness to pay, but meaning here the community's willingness to pay.
Class Divisions and Health Chances in Brazil
Authors: Santos José Alcides Figueiredo
Published: September 2011

This article analyzes the association between class divisions and health chances in the Brazilian population. It uses data from the health supplement of the 2008 National Household Survey. Multiple logistic regression models are estimated to determine the relation between social class and self-rated health status. This empirical investigation of health inequalities combines two modalities for social class comparison, thus benefiting from the potential utility of each. On the one hand, socioeconomic inequalities in health are analyzed with reference to the combination of two main assets, capital and expert knowledge, which generate material and health advantages in Brazil. The results demonstrate that social class measurements for Brazil capture a source of variation in health chances among social groups that is independent of education and family income. On the other hand, the use of theoretically univocal categories for exploring diversified class contrasts offers some explanatory starting points for health inequalities in the Brazilian population.
Federalism and Decentralization: Impact on International and Brazilian Health Policies
Authors: Leite Valéria Rodrigues , de Vasconcelos Cipriano Maia , Lima Kenio Costa
Published: September 2011

This article discusses the implications of decentralization in the light of international and Brazilian federalism, and its effects on public health policy. In a comparative analysis among countries, the authors find there is no single model; rather, each country has a unique structure of institutions and norms that have important implications for the operation of its health system. Brazil shares some similarities with other countries that have adopted a decentralized system and is assuming features ever closer to U.S. federalism, with a complex web of relationships. The degree of inequality among Brazilian municipalities and states, along with the budgetary imbalances caused by the minimal levels of resource utilization, undermines Brazil's constitutional principles and, consequently, its federalism. To ensure the constitutional mandate in Brazil, it is essential, as in other countries, to create a stable source of funds and increase the volume and efficiency of spending. Also important are investing in the training of managers, improving information systems, strengthening the principles of autonomy and interdependence, and defining patterns of cooperation within the federation.
Ownership, Financing, and Management Strategies of the Ten Largest For-Profit Nursing Home Chains in the United States
Authors: Harrington Charlene , Hauser Clarilee , Olney Brian , Rosenau Pauline Vaillancourt
Published: September 2011

This study examined the ownership, financing, and management strategies of the 10 largest for-profit nursing home chains in the United States, including the four largest chains purchased by private equity corporations. Descriptive data were collected from Internet searches, company reports, and other sources for the decade 1998–2008. Since 1998, the largest chains have made many changes in their ownership and structure, and some have converted from publicly traded companies to private ownership. This study shows the increasing complexity of corporate nursing home ownership and the lack of public information about ownership and financial status. The chains have used strategies to maximize shareholder and investor value that include increasing Medicare revenues, occupancy rates, and company diversification, establishing multiple layers of corporate ownership, developing real estate investment trusts, and creating limited liability companies. These strategies enhance shareholder and investor profits, reduce corporate taxes, and reduce liability risk. There is a need for greater transparency in ownership and financial reporting and for more government oversight of the largest for-profit chains, including those owned by private equity companies.
Development of Hot-Air Dried Cut Persimmon
Authors: Igual Marta , Castelló María Luisa , Roda Eva , Ortolá María Dolores
Published: September 2011

In this work the authors have studied the effect of hot-air drying with or without a previous osmotic dehydration pretreatment to produce dried cut persimmon with a different geometry (slices and sectors). A kinetic study has been carried out analysing mass variation, colour and texture changes in samples. Two sensory analyses were also performed considering drying time and geometry. Furthermore, the influence of 35 days of storage on optical and mechanical properties was also determined. The results obtained showed that geometry did not affect the parameters analyzed. According to the results of the kinetic study, the selected drying times were 8 and 12 hours. Osmotic pretreatment does not imply improvements in the final product. Judges preferred slices dried for 8 hours without osmotic pretreatment. The time of storage did not influence the optical and mechanical properties.
Pulsatile Lavage for the Enhancement of Pressure Ulcer Healing: A Randomized Controlled Trial
Authors: Ho Chester H. , Bensitel Toula , Wang Xiaofeng , Bogie Kath M.
Published: September 2011

Background

Pressure ulcer development is a common, serious complication after spinal cord injury (SCI). Although many biophysical agents are available for treatment, few randomized controlled trials of their efficacy have been done.

Objective

The study objective was to examine the efficacy of low-pressure pulsatile lavage treatment for stage III and IV pressure ulcers in people with SCI.

Design

This study was a randomized controlled trial. Participants and assessors were unaware of intervention assignments.

Setting

This study was conducted in an SCI tertiary care center inpatient unit.

Participants

Participants were 28 people with SCI and stage III and IV pelvic pressure ulcers; 14 participants each were randomly assigned to treatment and control (sham treatment) groups.

Intervention

Daily low-pressure pulsatile lavage treatment with 1 L of normal saline at 11 psi of pressure was applied to the treatment group along with standard dressing changes. The control group received only sham treatment and standard dressing changes.

Measurements

Linear and volume measurements of pressure ulcer dimensions were obtained weekly for 3 weeks.

Results

Statistical analysis with the t test revealed no statistically significant difference in demographics between groups. Random-coefficient models for analysis of linear and volume measurements revealed improvements over time for both groups. Time trend analysis revealed greater measurement decreases for the treatment group. Differences in rates of change (with 95% confidence intervals) for treatment and control groups, respectively, were: depth, −0.24 (0.09 to −0.58) cm/wk; width, −0.16 (0.06 to −0.39) cm/wk; length, −0.47 (0.18 to −1.12) cm/wk; and volume, −0.33 (0.13 to −0.80) cm3/wk.

Limitations

Study limitations were small sample size and inclusion of only one site. Additionally, participants were not queried about their group assignments.

Conclusions

Pulsatile lavage enhanced stage III and IV pelvic pressure ulcer healing rates in people with SCI relative to standard pressure ulcer treatment alone.
La Libye après Kadhafi : essai de prospective géopolitique du conflit libyen
Authors: Daguzan Jean-François , Moisseron Jean-Yves
Published: September 2011

Après quarante-deux ans de règne, le colonel Kadhafi va, d’une manière ou d’une autre, céder la place. Le mode de gouvernement ainsi que rôle de ce pays sur la sphère méditerranéo-maghrébo-africaine vont en être profondément modifiés. Nous changeons d’ère. Par la contrainte, l’obstination et son génie propre, le « guide » de la Libye avait imposé en interne un modèle de stabilité dans l’instabilité et, au plan externe, une politique extérieure poussée par une obsession unitaire variable (panarabisme, puis panafricanisme) et la préscience d’un destin libyen universel. La fin annoncée du régime renvoie donc à des réalités prosaïques : quelle sera la nouvelle structure de l’État libyen, s’il parvient déjà à se recomposer ? Comment sera comblé le vide stratégique laissé par la disparition des politiques kadhafiennes et quel sera l’impact de la guerre ? De fait, l’espace géopolitique maghrébin et sahélien redevient ouvert. La Libye de Kadhafi, même si elle soutenait les mouvements touaregs, contenait les migrations et luttait contre AQMI. Tout en s’étant « techniquement » ralliée au modèle occidental, elle était aussi un espace indépendant des rapports de forces globaux. Cet article essaye d’analyser les conséquences de la chute du régime de Kadhafi dans une perspective géopolitique.
Enchevêtrements géopolitiques autour de la lutte contre le terrorisme dans le Sahara
Authors: Tisseron Antonin
Published: September 2011

À la suite des attentats du 11 septembre 2001, l’Afrique du Nord est devenue pour les États-Unis un nouveau front de la « guerre contre le terrorisme ». Cet interventionnisme, dans une zone dans laquelle la France est traditionnellement présente, s’est toutefois heurté aux logiques et dynamiques géopolitiques à l’œuvre dans la région. Chaque acteur possède en effet ses objectifs, faisant du Sahara un espace dans lequel s’enchevêtrent des enjeux de pouvoir, de contrôle et d’influence au nom de la sécurité. Dans ce contexte, la volonté de donner un visage local à la lutte contre le terrorisme a jusque-là été limitée par l’absence de consensus sur la stratégie à adopter et le manque d’engagement du Mali. Si la guerre civile en Libye semble stimuler les dynamiques de rapprochement dans la région, la lutte contre le terrorisme et la criminalité dans la région reste cependant étroitement dépendante des capacités des États, de leurs relations avec les populations, et de leurs intérêts à toutes les échelles.
Portée et limites de l'hégémonie algérienne dans l'aire sahélo-maghrébine
Authors: Chena Salim
Published: September 2011

L’Algérie semble être la puissance hégémonique au Maghreb et au Sahel dans la mesure où elle dispose de ressources énergétiques stratégiques, d’une position privilégiée dans la lutte antiterroriste et d’un rôle important dans la répression des migrants irréguliers au Sahara et en Méditerranée. Ses imposantes ressources financières lui garantissent en outre une indépendance certaine dans ses politiques intérieure comme extérieure. En apparence univoque, cette situation doit faire face à de nombreux défis : des rivalités régionales anciennes, des alliances incertaines au Sahel, des acteurs extrarégionaux de plus en plus investis, une contestation sociale et politique intense. Cet article cherche à mettre en évidence les atouts et les limites de la mise en œuvre de la politique régionale algérienne.
Le Sahel comme espace de transit des stupéfiants. Acteurs et conséquences politiques
Authors: Julien Simon
Published: September 2011

Les pays sahéliens sont traversés depuis quelques années par des routes de trafics de stupéfiants, la cocaïne et le haschich. Cette arrivée témoigne à la fois de la transformation de la géoéconomie globale de ces deux produits mais également du renforcement des pays sahéliens dans leur spécialisation d’espace de transit, qui est l’un des modes de l’insertion de ces pays dans l’économie mondiale. En effet, si l’on prend l’exemple de la cocaïne, ce produit est arrivé en Afrique de l’Ouest et au Sahel au milieu des années 2000 en raison de l’émergence de l’Europe comme premier marché de consommation et de la dangerosité progressive (pour les trafiquants) des routes plus directes entre les zones de production en Amérique latine et l’Europe. Si l’on dresse une typologie des acteurs de ce trafic dans les pays traversés, on doit s’éloigner du modèle d’une mafia globale qui pourrait se payer des relais locaux. En effet, les acteurs africains, notamment ce que l’on peut appeler des mafias d’État dans certains pays, semblent incontournables. Les profits générés par ces trafics participent aux économies nationales mais ont déjà commencé à financer la politique et donc à produire du politique.
Circulations marchandes au Sahara : entre licite et illicite
Authors: Scheele Judith
Published: September 2011

Les échanges régionaux sont nécessaires aux économies locales sahariennes. Au gré de la conjoncture, ces échanges et les réseaux qui les sous-tendent ont toujours servi de relais à d’autres courants commerciaux : transsahariens et transrégionaux. À la main-d’œuvre, au thé, au coton ou au sucre convoyés vers et à travers le Sahara au XIX e siècle se sont ainsi ajoutés, au cours du XX e siècle, des produits manufacturés provenant des usines subventionnées du Maghreb, puis des marchandises illicites, comme des cigarettes de contrebande, des voitures volées, des armes et de la drogue. Or ces trafics ne représentent qu’une partie minime des échanges sur le terrain et s’inscrivent nécessairement dans des structures familiales plus anciennes, décentralisées, flexibles et pour partie vulnérables aux interventions extérieures. Aujourd’hui comme par le passé, c’est avant tout la capacité à se baser sur ces structures régionales, tout en s’adaptant à la conjoncture, qui permet de réussir.