bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential Regulation of Immune Responses and Macrophage/Neuron Interactions in the Dorsal Root Ganglion in Young and Adult Rats following Nerve Injury
Authors: Vega-Avelaira David , Géranton Sandrine M , Fitzgerald Maria
Published: December 2009

Background

Neuropathic pain is an apparently spontaneous experience triggered by abnormal physiology of the peripheral or central nervous system, which evolves with time. Neuropathic pain arising from peripheral nerve injury is characterized by a combination of spontaneous pain, hyperalgesia and allodynia. There is no evidence of this type of pain in human infants or rat pups; brachial plexus avulsion, which causes intense neuropathic pain in adults, is not painful when the injury is sustained at birth. Since infants are capable of nociception from before birth and display both acute and chronic inflammatory pain behaviour from an early neonatal age, it appears that the mechanisms underlying neuropathic pain are differentially regulated over a prolonged postnatal period.

Results

We have performed a microarray analysis of the rat L4/L5 dorsal root ganglia (DRG), 7 days post spared nerve injury, a model of neuropathic pain. Genes that are regulated in adult rats displaying neuropathic behaviour were compared to those regulated in young rats (10 days old) that did not show the same neuropathic behaviour. The results show a set of genes, differentially regulated in the adult DRG, that are principally involved in immune system modulation. A functional consequence of this different immune response to injury is that resident macrophages cluster around the large A sensory neuron bodies in the adult DRG seven days post injury, whereas the macrophages in young DRG remain scattered evenly throughout the ganglion, as in controls.

Conclusions

The results show, for the first time, a major difference in the neuroimmune response to nerve injury in the dorsal root ganglion of young and adult rats. Differential analysis reveals a new set of immune related genes in the ganglia, that are differentially regulated in adult neuropathic pain, and that are consistent with the selective activation of macrophages around adult, but not young large A sensory neurons post injury. These differences may contribute to the reduced incidence of neuropathic pain in infants.
Reversal of childhood idiopathic scoliosis in an adult, without surgery: a case report and literature review
Authors: Brooks William J , Krupinski Elizabeth A , Hawes Martha C
Published: December 2009

Background

Some patients with mild or moderate thoracic scoliosis (Cobb angle <50-60 degrees) suffer disproportionate impairment of pulmonary function associated with deformities in the sagittal plane and reduced flexibility of the spine and chest cage. Long-term improvement in the clinical signs and symptoms of childhood onset scoliosis in an adult, without surgical intervention, has not been documented previously.

Case presentation

A diagnosis of thoracic scoliosis (Cobb angle 45 degrees) with pectus excavatum and thoracic hypokyphosis in a female patient (DOB 9/17/52) was made in June 1964. Immediate spinal fusion was strongly recommended, but the patient elected a daily home exercise program taught during a 6-week period of training by a physical therapist. This regime was carried out through 1992, with daily aerobic exercise added in 1974. The Cobb angle of the primary thoracic curvature remained unchanged. Ongoing clinical symptoms included dyspnea at rest and recurrent respiratory infections. A period of multimodal treatment with clinical monitoring and treatment by an osteopathic physician was initiated when the patient was 40 years old. This included deep tissue massage (1992-1996); outpatient psychological therapy (1992-1993); a daily home exercise program focused on mobilization of the chest wall (1992-2005); and manipulative medicine (1994-1995, 1999-2000). Progressive improvement in chest wall excursion, increased thoracic kyphosis, and resolution of long-standing respiratory symptoms occurred concomitant with a >10 degree decrease in Cobb angle magnitude of the primary thoracic curvature.

Conclusion

This report documents improved chest wall function and resolution of respiratory symptoms in response to nonsurgical approaches in an adult female, diagnosed at age eleven years with idiopathic scoliosis.
Genome-wide gene-based analysis of rheumatoid arthritis-associated interaction with PTPN22 and HLA-DRB1
Authors: Qiao Bo , Huang Chien Hsun , Cong Lei , Xie Jun , Lo Shaw-Hwa , Zheng Tian
Published: December 2009

The genes PTPN22 and HLA-DRB1 have been found by a number of studies to confer an increased risk for rheumatoid arthritis (RA), which indicates that both genes play an important role in RA etiology. It is believed that they not only have strong association with RA individually, but also interact with other related genes that have not been found to have predisposing RA mutations. In this paper, we conduct genome-wide searches for RA-associated gene-gene interactions that involve PTPN22 or HLA-DRB1 using the Genetic Analysis Workshop 16 Problem 1 data from the North American Rheumatoid Arthritis Consortium. MGC13017, HSPCAL3, MIA, PTPNS1L, and IGLVI-70, which showed association with RA in previous studies, have been confirmed in our analysis.
Safety of trastuzumab (Herceptin®) during pregnancy: two case reports
Authors: Goodyer Matthew J , Ismail Jeffri RM , O'Reilly Seamus P , Moylan Eugene J , Ryan C Anthony M , Hughes Paul AF , O'Connor Alan
Published: December 2009

We report on two cases of women on trastuzumab therapy for breast cancer who became pregnant and delivered healthy live infants. At the time of reporting the children are growing and developing normally (ages 3 and 2).
Nutritional Programming Affects Hypothalamic Organization and Early Response to Leptin
Authors: Coupé Bérengère , Amarger Valérie , Grit Isabelle , Benani Alexandre , Parnet Patricia
Published: December 2009

Nutritional programming, taking place in utero or early after birth, is closely linked with metabolic and appetite disorders in adulthood. Following the hypothesis that nutritional programming impacts hypothalamic neuronal organization, we report on discrepancies of multiple molecular and cellular early events that take place in the hypothalamus of rats submitted to intrauterine growth restriction (IUGR). Expression screening performed on hypothalami from IUGR rats at birth and at postnatal d 12 identified changes in gene expression of neurodevelopmental process (cell differentiation and cytoskeleton organization). Additionally, a slight reduction of agouti-related protein and a strong reduction of α-MSH-immunoreactive efferent fibers were demonstrated in the paraventricular nucleus of IUGR rats. Rapid catch-up growth of IUGR rats, 5 d after birth, had a positive effect on neurodevelopmental factors and on neuronal projections emanating from the arcuate nucleus. The molecular and cellular anomalies detected in IUGR rats can be related to the reduced and delayed plasma leptin surge from d 0–16 when compared with control and IUGR rats with catch-up growth. However, the ability of leptin to activate intracellular signaling in arcuate nucleus neurons was not reduced in IUGR rats. Other mechanism such as epigenetic regulation of the major appetite-regulating neuropeptides genes was analyzed in parallel with their mRNA expression during postnatal development. This study reveals the importance of an early catch-up growth that reduces abnormal organization of hypothalamic pathways involved in energy homeostasis, whereas protein restriction, maintained during postnatal development leads to an important immaturity of the hypothalamus.
Minireview: Nanoparticles and the Immune System
Authors: Zolnik Banu S. , González-Fernández África , Sadrieh Nakissa , Dobrovolskaia Marina A.
Published: December 2009

Today nanotechnology is finding growing applications in industry, biology, and medicine. The clear benefits of using nanosized products in various biological and medical applications are often challenged by concerns about the lack of adequate data regarding their toxicity. One area of interest involves the interactions between nanoparticles and the components of the immune system. Nanoparticles can be engineered to either avoid immune system recognition or specifically inhibit or enhance the immune responses. We review herein reported observations on nanoparticle-mediated immunostimulation and immunosuppression, focusing on possible theories regarding how manipulation of particle physicochemical properties can influence their interaction with immune cells to attain desirable immunomodulation and avoid undesirable immunotoxicity.
Arcuate Nucleus Proopiomelanocortin Neurons Mediate the Acute Anorectic Actions of Leukemia Inhibitory Factor via gp130
Authors: Grossberg Aaron J. , Scarlett Jarrad M. , Zhu XinXia , Bowe Darren D. , Batra Ayesha K. , Braun Theodore P. , Marks Daniel L.
Published: December 2009

The proinflammatory cytokine leukemia inhibitory factor (LIF) is induced in disease states and is known to inhibit food intake when administered centrally. However, the neural pathways underlying this effect are not well understood. We demonstrate that LIF acutely inhibits food intake by directly activating pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus. We show that arcuate POMC neurons express the LIF-R, and that LIF stimulates the release of the anorexigenic peptide, α-MSH from ex vivo hypothalami. Transgenic mice lacking gp130, the signal transducing subunit of the LIF-R complex, specifically in POMC neurons fail to respond to LIF. Furthermore, LIF does not stimulate the release of α-MSH from the transgenic hypothalamic explants. These findings indicate that POMC neurons mediate the acute anorectic actions of central LIF administration and provide a mechanistic link between inflammation and food intake.
Associations among Metabolic Syndrome, Ischemia, Inflammatory, Oxidatives, and Lipids Biomarkers
Authors: Valle Gottlieb Maria Gabriela , da Cruz Ivana Beatrice Mânica , Duarte Marta M. F. , Moresco Rafael Noal , Wiehe Mário , Schwanke Carla Helena Augustin , Bodanese Luiz Carlos
Published: December 2009

Context: Metabolic syndrome (MS) is described as a cluster of cardiometabolic risk factors. Studies suggest that ischemia-modified albumin (IMA) is a biomarker of cardiovascular diseases. IMA levels could be associated with cardiometabolic risks and represent a possible indication of microvascular dysfunction in MS patients.

Objective: To confirm this possible association, we evaluated the association between IMA levels and MS.

Design: We performed a case-control study (32 healthy individuals and 74 subjects with MS) to evaluate the association between MS, IMA, and other biomarkers [high-sensitivity C-reactive protein (hs-CRP), oxidized low-density lipoprotein (OxLDL), oxidized low-density lipoprotein autoantibodies (anti-OxLDL), IL-6, lipid profile, and glucose].

Results: The MS group showed higher levels of IMA (0.618 ± 0.1355) as well as higher levels of hs-CRP, OxLDL, anti-OxLDL, and IL-6 than did control subjects (IMA = 0.338 ± 0.0486) (P < 0.01). Multivariate analysis showed that IMA and MS association was independent of sex, age, diabetes mellitus 2, and hypercholesterolemia.

Conclusion: We found an association between IMA and MS. Additional studies including prospective genetic variation approaches need to be performed to help elucidate this association between IMA and MS and its potential clinical role.
Information and Communications Technology in U.s. Health Care: Why Is Adoption So Slow and Is Slower Better?
Authors: Christensen Michael C. , Remler Dahlia
Published: December 2009

Politicians across the political spectrum support greater investment in health care information and communications technology (ICT) and expect it to significantly decrease costs and improve health outcomes. We address three policy questions about adoption of ICT in health care: First, why is there so little adoption? Second, what policies will facilitate and accelerate adoption? Third, what is the best pace for adoption? We first describe the unusual economics of ICT, particularly network externalities, and then determine how those economics interact with and are exacerbated by the unusual economics of health care. High replacement costs and the need for technical compatibility are general barriers to ICT adoption and often result in lock-in to adopted technologies. These effects are compounded in health care because the markets for health care services, health insurance, and labor are interlinked. In addition, the government interacts with all markets in its role as an insurer. Patient heterogeneity further exacerbates these effects. Finally, ICT markets are often characterized by natural monopolies, resulting in little product diversity, an effect ill-suited to patient heterogeneity. The ongoing process for setting technical standards for health care ICT is critical but needs to include all relevant stakeholders, including patient groups. The process must be careful (i.e., slow), flexible, and allow for as much diversity as possible. We find that waiting to adopt ICT is a surprisingly wise policy.
Comparing normal walking and compensated walking: Their stability and perturbation resistance. A simulation study
Authors: Yu W , Ikemoto Y , Acharya R , Unoue J
Published: December 2009

People usually develop different kinds of compensated gait in response to local function deficits, such as muscle weakness, spasticity in specific muscle groups, or joint stiffness, in order to overcome the falling risk factors. Compensated walking has been analysed empirically in the impaired gait analysis area. However, the compensation could be identified spatially and temporally. The stability and perturbation resistance of compensated walking have not been analysed quantitatively. In this research, a biomimetic human walking simulator was employed to model one individual paraplegic subject with plantarflexor spasticity. The pes equinus was expressed by biasing the outputs of plantarflexor neurons corresponding to the spastic muscles. Then, the compensatory mechanism was explored by adjusting the outputs of the other muscles. It was shown that this approach can be used for quantitative analysis of the spastic gait and compensated walking. Thus, this research can improve the understanding of the behaviour of compensated walking, bringing insights not only for building useful walking assist systems with high safety but also for designing effective rehabilitation interventions.
Learning from Schelling's Strategy of Conflict
Authors: Myerson Roger B.
Published: December 2009

Thomas Schelling's Strategy of Conflict is a masterpiece that should be recognized as one of the most important and influential books in social theory. This paper reviews some of the important ideas in Strategy of Conflict and considers some of the broader impact that this book has had on game theory, economics, and social theory. By his emphasis on the critical importance of information and commitment in strategic dynamics, Schelling played a vital role in stimulating the development of non-cooperative game theory. More broadly, Schelling's analysis of games with multiple equilibria has redefined the scope of economics and its place in the social sciences. (JEL D74, F51, H56)
Cool-Season Turfgrass Survival on Two Former Golf Courses in Michigan
Authors: Garrison Mark A. , Stier John C. , Rogers John N. , Kowalewski Alec R.
Published: December 2009

Most turfgrass species have been listed as either invasive or potentially invasive species in the U.S., but few data exist to verify their invasiveness. Our objective was to determine cool-season turfgrass survival on two abandoned golf courses to assess their invasive potential in unmanaged sites. Maintenance operations ceased at Matheson Greens Golf Course in 2000 and at Four Winds Golf Course in 2003. The frequency and abundance of creeping bentgrass, Kentucky bluegrass, and fine fescues in quadrats placed along transects were recorded and compared to other cover such as herbaceous dicots and bare soil in 2005 and 2007. Turfgrasses at both courses were unable to maintain monocultures. All turfgrasses were nearly absent from Matheson Greens Golf Course 5 yr after maintenance operations ceased. At the Four Winds Golf Course site, creeping bentgrass comprised less than 25% cover on former putting greens by 2007, and was rarely found outside of the former putting green areas. Kentucky bluegrass cover ranged from 5 to 75% on the former fairways. Herbaceous dicots usually dominated the former turf areas at both sites, and included noxious weeds such as Canada thistle and invasive weeds such as spotted knapweed.
Decision Analysis to Evaluate Control Strategies for Crested Wheatgrass (Agropyron cristatum) in Grasslands National Park of Canada
Authors: Frid Leonardo , Wilmshurst John F.
Published: December 2009

Protected area managers often face uncertainty when managing invasive plants at the landscape scale. Crested wheatgrass, a popular forage crop in the Great Plains since the 1930s, is an aggressive invader of native grassland and a problem for land managers in protected areas where seeded roadsides and abandoned fields encroach into the native mixed-grass prairie. Given limited resources, land managers need to determine the best strategy for reducing the cover of crested wheatgrass. However, there is a high degree of uncertainty associated with the dynamics of crested wheatgrass spread and control. To compare alternative management strategies for crested wheatgrass in the face of uncertainty, we conducted a decision analysis based on information from Grasslands National Park. Our analysis involves the use of a spatially explicit model that incorporates alternative management strategies and hypotheses about crested wheatgrass spread and control dynamics. Using a decision tree and assigning probabilities to our alternative hypotheses, we calculated the expected outcome of each management alternative and ranked these alternatives. Because the probabilities assigned to alternative hypotheses are also uncertain, we conducted a sensitivity analysis of the full probability space. Our results show that under current funding levels it is always best to prioritize the early detection and control of new infestations. Monitoring the effectiveness of control is paramount to long-term success, emphasising the need for adaptive approaches to invasive plant management. This type of decision analysis approach could be applied to other invasive plants where there is a need to find management strategies that are robust to uncertainty in the current understanding of how these plants are best managed.
Water Loss and Salvage in Saltcedar (Tamarixspp.) Stands on the Pecos River, Texas
Authors: Hatler William L. , Hart Charles R.
Published: December 2009

Water use by saltcedar, an invasive phreatophyte, is of significant concern in many riparian zones in the western United States. Diurnal groundwater fluctuations were analyzed to estimate evapotranspiration and water salvage (water available for other ecological functions) in saltcedar stands over a 6-yr period on a site along the Pecos River in Texas. Seasonal stand-level saltcedar water loss at an untreated control site ranged from 0.42 to 1.18 m/yr. Seasonal water salvage following application of imazapyr ranged from 31% 4 yr after treatment to 82% 2 yr after treatment. Significant water savings may be achieved by chemical saltcedar control, dependent upon water use by replacement vegetation and saltcedar regrowth. A regrowth management strategy is essential to maintain long-term water salvage.
Competitive Effect of Two Nonnative Grasses on a Native Grass in Southern Arizona
Authors: Stevens Jason M. , Fehmi Jeffrey S.
Published: December 2009

Invasive buffelgrass, potentially invasive natalgrass, and the native grass Arizona cottontop were evaluated for their competitive response to one another in southern Arizona. Targets and neighbors were transplanted in a full-factorial randomized complete-block design consisting of nine pairwise combinations and each species alone (n = 120). Plant pairs were separated by 5 cm and allowed to grow during the 2007 monsoon season (101 d). Aboveground biomass, reproduction, and Arizona cottontop water-potential data were collected. Buffelgrass neighbors reduced aboveground biomass production and reproductive output significantly more than did intraspecific neighbors (P < 0.05), whereas natalgrass neighbors did not significantly affect Arizona cottontop biomass production or reproductive output (P > 0.05). Cottontop and buffelgrass had no significant effect on natalgrass biomass. Similarly, cottontop and natalgrass neighbors had no neighbor effect on the biomass of buffelgrass. Arizona cottontop plants that neighbored buffelgrass averaged a significantly lower water-potential value of −3.18 MPa (P < 0.05), compared with −1.17, −0.93, and −1.32 MPa for control plants (i.e., those with no neighbor), intraspecific neighbors, and natalgrass neighbors, respectively. Although buffelgrass competitive ability is consistent with its invasiveness when grown with native Arizona cottontop, natalgrass was an intermediate competitor. This suggests that natalgrass is less of a competitive threat to native perennial grasses than buffelgrass, but that it may be more tolerant to resource depletion (i.e., the presence of buffelgrass) relative to Arizona cottontop.
Hybridization between Invasive Populations of Dalmatian Toadflax (Linaria dalmatica) and Yellow Toadflax (Linaria vulgaris)
Authors: Ward Sarah M. , Fleischmann Caren E. , Turner Marie F. , Sing Sharlene E.
Published: December 2009

Although there is evidence that interspecific hybridization can initiate invasion by nonnative plants, there are few documented examples of novel hybridization events between introduced plant species already exhibiting invasive behavior. We conducted morphometric and molecular analyses of toadflax plants with intermediate morphology found at two sites in Montana, which were co-invaded by yellow toadflax and Dalmatian toadflax. Field-collected putative hybrid plants had intermediate morphometric scores (mean 0.47, on a scale of 0.0 = indistinguishable from Dalmatian toadflax to 1.0 = indistinguishable from yellow toadflax) for a suite of phenotypic traits that differentiate the parent species (leaf length : width ratio, growth form, seed morphology, inflorescence type, and ventral petal shape). Inter-simple sequence repeat (ISSR) analysis of a subset of these putative hybrids revealed combinations of species-diagnostic bands, confirming the presence of DNA from both parent species. Controlled interspecific hand-pollinations generated viable first generation (F1) hybrid plants that also had intermediate morphometric scores (mean 0.46) and a mix of species-diagnostic ISSR bands from both parents. The hand-generated F1hybrids crossed readily with both parent species to produce viable first generation backcrossed (BC1) plants. Our results confirm that hybridization is occurring between invasive populations of yellow toadflax and Dalmatian toadflax, and that the hybrid progeny are viable and fertile. This example of hybridization between alien congeners is of concern as the parent taxa are already known to be highly invasive. Further research is needed to assess the invasive potential of hybrid toadflax populations, and the likelihood of introgressive trait transfer between the parent species.
Differential Herbicide Response among Three Phenotypes ofCabomba caroliniana
Authors: Bultemeier Brett W. , Netherland Mike D. , Ferrell Jason A. , Haller William T.
Published: December 2009

Cabomba is a submersed aquatic plant native to the southeastern United States that is commonly sold worldwide through the aquarium trade. While infrequently managed in its native range, cabomba has recently been reported as invasive and tolerant to management efforts in the northern areas of the United States and in other countries. Invasive populations of cabomba are characterized by a phenotype that is bright green. In contrast, cabomba native to the southeastern United States is characterized by a red phenotype, while plants sold through the aquarium trade have intermediate characteristics of both the green and red phenotypes. The response of the three cabomba phenotypes to selected herbicides was evaluated by measuring photosynthetic response over the course of a static 144-hr exposure. Plants were exposed to the maximum recommended use-rates of 2,4-D, carfentrazone, copper, diquat, endothall (amine and dipotasium salt formulation), flumioxazin, quinclorac, triclopyr, and a combination of diquat and copper. A submersed plant species known to be sensitive to each of these herbicides was also included to compare photosynthetic response of the cabomba to a susceptible plant. The photosynthetic response of the red and green phenotypes differed following exposure to carfentrazone, diquat, 2,4-D, triclopyr, and flumioxazin. Diquat, diquat plus copper, endothall (amine salt), and flumioxazin were the only products that resulted in a greater than 50% reduction of photosynthesis in all three phenotypes of cabomba. A second experiment was conducted where all three phenotypes of cabomba were exposed to these four herbicides for 24 hr, and photosynthesis was evaluated. Following the 24-hr exposure, results further documented distinct response differences between the green and red phenotypes, with the green phenotype demonstrating a reduced sensitivity to the herbicides evaluated. Results demonstrate clear phenotypic differences in response to herbicide treatments and lack of susceptibility of cabomba to most herbicides.
A Comparison between Multi-Fractured Horizontal and Fishbone Wells for Development of Low-Permeability Fields
Authors: Yu Xiance , Guo Boyun , Ai Chi , Bu Zhidan
Published: December 2009

Development of oil and gas fields with low-permeability reservoirs presents a unique challenge to the energy industry due to the low productivity of individual wells and the high cost of drilling and fracturing a large number of wells. This study investigated the possibility of using fishbone wells to maximize the net-present value (NPV) of field development. A comparison of multi-fractured horizontal wells and fishbone wells for tight gas field development is presented in this paper.

Multi-fractured horizontal wells have been used to improve oil and gas production from low-permeability reservoirs for over a decade. The problems associated with this type of wells are well productivity decline due to fracture closure with time and uncertainty of fracture propagation due to the lack of knowledge of formation stresses. The disadvantages of multi-fractured horizontal wells may be avoided by using fishbone wells, a new technology developed in the recent years. In this study, we compared the net present values (NPV) of two development plans for a generic gas field using multi-fractured horizontal wells and fishbone wells. We found that these two types of wells can generate comparable NPV values. We conclude that as the drilling technology develops, use of fishbone wells with increased number of rib holes will be more beneficial than multifractured wells in developing tight gas fields.
Integrating Microseismic Mapping, Fracture Modeling and Reservoir Simulation Optimizes Well Performance in the Changqing Field
Authors: Liu Xinghui , Lolon E. P. , Li Xianwen , Chen Baochun , Cipolla C. L. , Wang Chengwang
Published: December 2009

The Changqing field consists of many individual oil fields that stretch across a large area in the Ordos Basin of north central China. Oil reservoirs in the Changqing field typically consist of stacked sand/shale deposits with the majority of the target zones having low permeabilities of 0.05 to 0.3 mD. All oil wells completed in these tight reservoirs are fracture stimulated to achieve commercial production. Fracture stimulation is also commonly done in injection wells to enhance injectivity in reservoirs under waterflooding. In a successful water injection program, it is critical to achieve optimal fracture parameters (fracture length, azimuth, and conductivity) for both the injection and production wells. Improper well placement and fracture design can lead to high injection pressures, early water breakthrough, and overall low oil recovery. This paper presents the results of two case studies to evaluate hydraulically fractured well performance of two oil reservoirs in the Changqing field. Microseismic fracture mapping was used to determine fracture geometry and azimuth. Fracture modeling was used to determine effective fracture length, height, and conductivity. The microseismic mapping and fracture modeling results were integrated into a multi-layer, multi-phase and multi-well reservoir simulator to determine the effectiveness of fracture geometry, conductivity and well placement on water injectivity and oil recovery for inverse 5-spot and rectangular drive water injection schemes.
Integrated Reservoir Characterization, Modeling and Simulation of Lower Sihapas in Kurau Field, Sumatra, Indonesia
Authors: Firmanto Tri , Suyatno Iman Suripto , Gomaa Ezzat , Priyantoro Jati , Sidik Benny , Pujiriyanto Andry , Ong Diana , Asmara Bondan , Rahmawan Irvan , Septiawan Henry , Gustiawan Eppy , Wibowo Arif
Published: December 2009

A 1000 bopd was achieved from successful integrated study of Kurau Field in 2007 year. All best practices of the study describe in this paper. The objective of this study is to build a complete reservoir model from an integrated study involving all aspects of engineering & G&G, such as data review, G&G modeling, reservoir characterization, reservoir modeling and prediction, in order to optimize the development of Kurau Field. The milestone starts from interpreting the 3D seismic data, structural or zonation model, petrophysics analysis, reservoir characterization, static modeling, dynamic modeling, and proceeds until it reaches the development and performance prediction of Kurau Field.

More than just a simple model, Kurau reservoir model resulted from all data and results from G&G such as interpretation of 3D seismic, G&G modeling (static model), environmental correction for well logs from Petrophysical Software analysis together with reservoir engineering works such as rock and fluid properties analysis, rock characterization and also production engineering aspects. Geomodeling software was used to build 3D seismic to reservoir modeling, with additional Simulation Software to complete the simulation.

The history matching analysis shows a satisfactory level of production profile comparison results of model performances with actual production data. Several infill wells and even EOR potential can be identified from this reservoir simulation model. Using an integrated study workflow from G&G, Petrophysic and Reservoir Engineering work had greatly improved the reliability of this reservoir model. Recently updated, those infill wells proved able to yield an additional 1000 bopd to Kurau field, as previously predicted.

An integrated study from Engineering & G&G Department was required when we attempted to build a reservoir model. Such a model can be used to determine infill well potential, work over result estimation and also the EOR project. Achieving an increment of the oil recovery factor is the most beneficial result from this reservoir simulation.
World's First Reverse-Port Uphill Openhole Gravel Pack with Swellable Packers
Authors: Jansen Rene , Koksaloglu Bengi , Holweg Philip , Hamedi Riehdwan , Dawson Mark , Chay Bryan , Mok David , Razien Ali
Published: December 2009

Brunei Shell Petroleum operates the Seria North Flank (SNF) field in Brunei Darussalam. When accessed from a land location, this near shore development requires that wells be drilled and completed at angles of up to 127 degrees to optimally develop the field.

The wells are drilled from Brunei's coastline under the South China Sea intersecting the SNF fields while targeting the optimum points of recovery within the reservoirs. These "fishhook wells" require sand control over long uphill reservoir sections as well as a viable economic delivery method. Current sand control methods were deemed unlikely to succeed in this environment and as such these complicated uphill wellbore trajectories required the development of a novel, reverse-port gravel-pack system.

This paper will discuss the gravel-pack system and how it addressed the difficult scenarios, including: How the openhole horizontal well was gravel packed from "toe to heel" as opposed to the conventional "heel to toe" method.Requirements for a tailored solution to carry the fluid through the system without bridging off in the workstring, washpipe or openhole sections.Well production and reservoir control

The multi-layered reservoirs required a form of open-hole and internal zonal barriers in order to efficiently control the production of each zone. Swellable packers were used in both environments to assist in providing the selectivity of zones.

In addition to these solutions, a delayed filter-cake removal system was used to clean up the polymers and filter cake in the open hole prior to production. Management and control of production of the multiple oil and gas zones is provided through the use of an intelligent completion system. These combined technologies enabled fully integrated well and reservoir management.

The world's first successful reverse-port uphill gravel pack in a fishhook well was completed in August 2007. The details of the design of a reverse-port gravel-pack tool, fluid analysis, flow-friction behavior, filter cake testing, gravel-pack installation, and well performance results of this and other similar completions will be provided in this paper.
Was that Last Project a 'Near Miss' or 'Miles Wide of the Target'?
Authors: Adam Peter
Published: December 2009

This paper is a case study on improving the quality of project approval decisions within an operating oil and gas company, by improving the existing deterministic economic evaluation workflow to answer questions such as: Did our project outcomes meet our expectations, or were we miles off?What, no production? A write-off! How could this be?Do we give the project team a bonus this year?

The methodology employed was to: Determine the insights needed by decision-makers to improve the quality of project approval decisions, and post-project, to appraise the project team's performance.Update the existing evaluation workflow to deliver these insights.Measure the impact of the updated workflow in terms of project proposal quality, and actual verses proposed project outcomes.

The improvements from this simple and inexpensive workflow include: Fewer and better project proposals.Better project sanction decisions.Fast and focused project look-backs.More objective evaluation of project team performance.

Conclusions from this project are: Improved project sanction decisions result from using a probabilistic economic valuation.This method is straight-forward to implement, requiring management support but minimal expense, and is equally applicable for small and large companies.Visualising the entire range of project outcomes benefits all stakeholders:Project team members quickly identify key project drivers, allowing more time to investigate ways to reduce their uncertainty.

This workflow is extended to quantify the uncertainty in production and cost forecasts for annual and long-range budgets.
Time Lapse Neutron Logging Improves Formation Evaluation and Reduces Rig Time in the Gulf of Thailand
Authors: Whittlesey Karen , Logan James , Rossiter Huw
Published: December 2009

In Chevron's Gulf of Thailand ('GOT') operations, costs drive logging and formation evaluation. Programs for logging and evaluation are based on consideration of perceived value and the potential for comprehensive utilization. Well lifespan is short, and economics rarely provide for the use of higher technology at non-discounted prices. A recent business initiative recognized that oil vs gas fluid identification from logging measurements was a risk that should be mitigated providing a major opportunity to add value.

Historical experience has shown, that the diameter of invasion can be greater than twenty inches by the time a well is logged with wireline which is beyond the limits of investigation for density and neutron tools, rendering the interpretation of fluid types ambiguous in most hydrocarbon bearing sands in this basin. To reduce this uncertainty, comprehensive wireline formation pressure programs have been run to assess hydrocarbon gradients but because sands are thin and permeabilities are low these programs have had various degrees of success.

LWD (logging while drilling) neutron tools can obtain data prior to invasion. Overlaying the LWD neutron and wireline neutron reveals time-lapse differences between the logs, shows gas intervals, and confirms liquid-filled zones. The technique can also infer inflow permeability for some of the more shaley gas reservoirs. Positive fluid identifications have been confirmed by follow up wireline pressure gradients, NMR logs, and production tests.

This paper will show many great examples of the evolution of a good idea. It will also demonstrate the effective use of technology, the buy-in from drilling engineers, and value of information benefits to the asset teams. Logging programs in the GOT once thought to be static, have rapidly evolved with insightful technology and the demonstration of its value.
Inversion of Induction Logging Data Constrained by Fluid-Flow Simulator
Authors: Liang Lin , Abubakar Aria , Habashy Tarek
Published: December 2009

Induction logging technique is one of the important tools for determining the formation resistivity of the subsurface. The near-wellbore formation resistivity is affected by the invasion of water-based mud-filtrate if there is a salt concentration contrast between the mud-filtrate and the in-situ formation water. The flushed-zone resistivity (Rxo), the undisturbed-zone resistivity (Rt) and the diameter of invasion (Di) can be estimated from the interpretation of array induction logging measurements through a model-based inversion process. Conventionally, the inversion assumes a "layer cake model" with three-parameter (Rxo, Rt and Di) invasion model or with a four-parameter invasion model that incorporates a ramped transition zone.

In this study, we introduce a 2.5D inversion approach for interpreting the induction logging data. The inversion is constrained by using a multiphase fluid flow model (incorporating pressure data if available) which simulates the mud-filtrate invasion process and calculates the spatial distribution of the water saturation and the salt concentration, which are in turn transformed into the formation conductivity using a resistivity-saturation formula. In this way, the inverted invasion profile is consistent with the fluid flow physics and moreover accounts for gravity segregation effects. Jointly with the pressure data, the inversion estimates a parametric one-dimensional distribution of permeability and porosity.

Previous works either assumed that the mud-cake permeability is known and used the bottom-hole pressure as a boundary condition, or alternatively used an independent mud-cake growth and invasion model to calculate the dynamic invasion rate as a boundary condition to the fluid flow simulator at the wellbore surface. The dynamic invasion process is complicated and is affected by many factors such as mud properties, formation properties, geometry and drilling conditions. Hence, although possible, it is difficult to calculate the dynamic invasion rate. This study shows that it is possible to directly invert the mud-filtrate invasion volume from the fluid-flow-constrained inversion of the induction logging data. Moreover, this approach is not limited by the traditional interpretation of the formation test, which is based on a single phase model without taking into account invasion or assumes that the mud-filtrate has been cleaned up from the formation testing zone. The joint inversion of the induction logging and pressure data demonstrates the ability to provide a more reliable interpretation of formation permeability. The advantage of the approach presented here, is its possible generalization to three-dimensional geometries, for example dipping beds and highly deviated wells.
Advanced Methods To Design and Interpret Exploration Well Tests - Two Case Studies
Authors: Carnegie AJG , Ball Stephen , Maizeret Pierre-David , Taylor David , Manh Ho
Published: December 2009

Two Drill stem tests (DST) were conducted from a well X, in an offshore field that was in the exploration phase. A major objective of each test was to identify whether the seismic anomalies seen between well X and a bounding fault act as impediments to flow. This objective was robustly achieved, together with all other test objectives, without unnecessary expenditure of rig time.

An expert had planned the tests using analytic models and his considerable experience. Pressure/rate deconvolution was used to support the interpretation. Since the tests were performed, a new method for DST design has been (recently) developed. It uses Experimental Design to enable systematic calculation of the expected chance of success of a DST when several scenarios exist for the reservoir. The method also provides a way to maximize these chances, given fixed resources, such as rig time.

The new method was tested against the actual plans used for the DST's in well X, and indicated that they were indeed optimal.

Experimental Design is rapidly gaining industry acceptance as a method to assess risks in field developments that arise due to reservoir uncertainty. But, its application to DST design when significant reservoir uncertainty exists, has rarely (if ever) been reported. The new method may exploit analytic models and/or finite difference simulation (coupled with geological modeling packages) to predict DST behavior. It is efficient and may be employed to rapidly redesign DST programs whenever new data becomes available, for example after open-hole logs have been acquired in a well to be tested. The cases described here illustrate why Pressure/rate deconvolution shows much promise to improve pressure transient interpretation.
Radioactive Sources in Petroleum Industry: Applications, Concerns and Alternatives
Authors: Badruzzaman A. , Barnes S. , Bair F. , Grice K.
Published: December 2009

Radioactive sources utilized in many industries, including the petroleum industry, have raised security, safety and environmental concerns. Oilfield sources are highly mobile, transported across the world and often used in remote locations. Despite safeguards and regulations, such sources have been lost, stuck down-hole, or breached. Concerns have been raised on sources being used in a radiological dispersal device (RDD). The US National Academy of Sciences, being concerned primarily with RDD, recently recommended replacing radioactive sources used in several industries with alternative sources. These include replacing Am-Be neutron sources used in porosity devices with either neutron generators which are switchable or with Cf-252 which would contain a lower amount of radioactivity. The lower risk Cs-137 source used in measuring density was spared at this time. However, a breached Cs-137 density source down-hole recently necessitated the setting up of a very long-term, elaborate monitoring program and thus such sources are of concern too.

This paper discusses the critical role of radioactive sources in petroleum exploration and production, protocols prescribed by regulators and the International Atomic Energy Agency for their safe use, concerns about their RDD potential, and lessons learned from a recent breached radioactive source incident in the field. The paper identifies additional procedures the oil industry needs to consider to use radioactive sources safely and securely, reviews the NAS recommendations and their potential impact on the industry, and describes alternatives to current chemical sources the industry is considering and the challenges which have arisen in making the transition.
Designing a Comprehensive Methodology as an AVO Analysis for Light Hydrocarbon Exploration Based on a Case Study
Authors: Parvizi R. , Norouzi G. H. , Sahabi F. , Maleki M. , Hajijomhouri H.
Published: December 2009

AVO (Amplitude Versus Offset) is one of the powerful methods in identifying the fluid type and lithology in subsurface exploration. In this paper, a comprehensive method has been designed which comprises of three parts: 1- Direct modeling 2-Inverse modeling 3- Cross plot interpretation. Each step has special roles. Direct Modeling can indicate the identity of attributes (lithology or fluid dependent attributes). The analysis has been done using both P-P and P-Sv attributes. Inverse modeling deals with real data and is fed from the results of direct modeling for characterization of the light hydrocarbon zones. The main role of cross plot interpretation is satisfaction of the results of the Inverse modeling and consequently increases the validity of them. This cross plot is also able to identify the lithology. Because of using Hodogram – Cross plot in this methodology, We able to manage the distribution of all points (anomalous and background points), So the small hydrocarbon zones is identifiable too. Distribution of points in wet zone is dense and in gaseous zone is expanded at Gradient – Normal Incidence Reflectivity crossplot. Using this methodology in Gorgan Plain (located in Iran) showed that fluid factor, SIGN, and possion reflectivity are fluid-dependent attributes. It also showed the normal incidence reflectivity and P-wave impedance reflectivity are lithology-dependent. Making the inverted sections of fluid-dependent attributes indicated two light hydrocarbon zones under the Cretaceous-Tertiary unconformity. It is expected that there is a wet zone under the one of this zones. Wet and gaseous zones are also satisfied by cross plot. Points distribution in cross plot of lithology-dependent attributes or fluid-dependent attributes is regular. Whereas considering simultaneous effect of both lithology and fluid attributes in cross plot results dispersive points distribution.
Estimating the Magnitude of Exhumation From 2D and 3D Seismic Velocity Datasets: A Case Study From Slyne Basin, Offshore Northwestern Ireland
Authors: Biancotto F. , Hardy R. J. J. , Jones S. M.
Published: December 2009

Exhumation describes vertical displacements of rocks from maximum depth of burial that results from the removal of overburden material. In this study we invert seismic velocity profiles from 2D and 3D seismic reflection datasets to constrain the distribution and the magnitude of exhumation within the Slyne Basin, offshore NW Ireland. The method has already been successfully applied to 2D datasets offshore Britain and Africa; this study is the first attempt to extract exhumation estimates from 3D seismic data. Inversion of 3D seismic velocity data yields a continuous map of exhumation across the entire 3D footprint. Exhumation estimates from 2D seismic sections agree with estimates from co-located 3D data. However, there is greater scatter in the 2D-derived exhumation estimates, most easily seen at line ties. This scatter in the 2D measurements arises because 2D seismic stacking velocities are less well constrained than 3D velocities. Together, the 2D and 3D seismic stacking velocity profiles can be used to estimate exhumation patterns on spatial scales >10 km to an accuracy of ±200 m. Many estimated changes in exhumation are associated with geological structures, suggesting confidence in the results. The margins of Slyne Basin have undergone about 1 km more erosion than the basin centre to form the Jurassic-Miocene composite unconformity. Inversion anticlines in the centre of the basin have undergone a few hundred metres more erosion at their crests than at their flanks. There is good agreement between 3D seismic-derived exhumation estimates and existing exhumation estimates using traditional techniques applied to borehole data. Overall, our results show that regional exhumation can be mapped in hitherto unprecedented detail using good quality seismic stacking velocity data.