bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integration of 3D Seismic in the Absence of Core Data to Mitigate Porosity Uncertainty in a Deep, Over Pressure Reservoir in Niger Delta
Authors: Basak Prahlad , Abdul-Kareem Abiola , Anyaehie James C , Esho Muyiwa 
Published: July 2014

Abstract
Determining reservoir porosity from density logs is possibly the most common practice in the industry over the years. Computation of porosity from density is largely affected by the grain density and fluid density used in the models. There are many best practices available in the industry to compute the grain density and fluid density with reasonable certainty. There are also many different models available which takes into account other available log responses like neutron porosity, resistivity, and shale volume to account for the uncertainties in the porosity computation. However, one of the areas that need some special attention is to integrate non-petrophysical data like seismic which can help reducing the porosity uncertainty significantly especially when no other calibration reference is available. Log measurements from the padded tools like density, neutron porosity are generally quality checked against caliper and other lithology indicators like gamma ray, resistivity, sonic etc. This paper demonstrates that porosity computation could also go wrong in a true gauge hole where density log reading apparently looks good and also showing right kind of deflection for changes in lithology. The situation can get quite complicated if the reservoir is highly over pressured and if there is no core data or regional data available.
In a deep, over pressured reservoir in the niger delta, with only two well penetrations, no core measurements, and no regional calibration reference, top quality recent 3D seismic data was integrated with the well data to mitigate uncertainties in reservoir porosity. The formation evaluation challenge was that log in one of the wells showed a relatively low density reading (hence high porosity) compared to the second well density over the same reservoir. However seismic amplitude did not support the porosity variation between the two wells hence leading to further investigation on identification and management of the observed uncertainties. This paper showcased in details how the seismic data was used to identify the wrong well log reading that lead to wrong prediction of porosity distribution and the accuracy of the integrated seismic and well log predicted properties when compared to actual well log result from a well that was later drilled in the same reservoir.
Feasibility Study of the use of Local Clay as Mud Material in Oil Well Drilling in Nigeria
Authors: Imuentinyan I. , Adewole E. S. 
Published: July 2014

Abstract
The present consumption of bentonite clay in the drilling operations in Nigeria alone can reach over 100 thousand tons a year and all of it is imported. The large consumption and the high importation cost of this material lead to an attempt to find a local substitute which can save a huge amount of hard currency that otherwise would be spent on importing.
This work focuses on the possibility of the utilization of local clay minerals as a basic material for drilling fluids used to drill oil and gas wells. Two samples of local clay were collected from Ikpoba River and Ovia River all in Edo State, Nigeria. API specifications for acceptable drilling mud were the basis for evaluation of the local clay. The properties of mud prepared from the local mud were improved economically by adding some cheap and available materials to the prepared mud. It was observed that the mud settles out from the water very fast after mixing, so additives was added (10grams of barite) which resulted in the increase of the weight and specific gravity of the mud. The local clay has significantly high sand content in comparison to the imported bentonite (67%). It has also low viscosity in comparison to commercial bentonite. Mud viscosity of the local clay was enhancement by adding Carboxymethylcellulose (CMC) and Tannin. After adding 3g of CMC and 2g of Tannin the Plastic Viscosity (PV) and the Yield Point (YP) of Ovia and Ikpoba were found to be 10 and 12, 7 and 10 respectively which compare closely with that of the imported bentonite of 6 for PV and 13 for YP.
These characteristics of the local clay make it a potential material for application as drilling fluid when subjected to enhancement by also locally available additives.
Post Drill Contacts Analysis: A Detailed Analysis on the Degree of Uncertainty and Reliability of Amplitude-Based vs. Stochastic Trap Analysis and Risking (STAR) Based Hydrocarbon Fluid Contact Prediction
Authors: Umahi Otuka , Chunduru Raghu , Lamens Jo , Amogu Daniel , Filbrandt Jack , Allison Eric , Adeogba Tola 
Published: July 2014

Abstract
In general, unconsolidated Tertiary deltaics in Niger Delta are characterized by a strong amplitude hydrocarbon response and are used successfully to predict hydrocarbon fluid contacts. Accurate definition of fluid contact is critical at every stage of prospect maturation. In areas, where amplitude support is inadequate, Stochastic Trap Analysis and Risking (STAR) tool has proven to be a reliable substitute in calculating the fluid contacts. STAR is based on Shell's global hydrocarbon column height database that shows a correlation between column height and fault shale gouge ratio (SGR). The programme calculates the SGR of trap defining faults in a Petrel 3D model and predicts a low-mid-high column height range for each reservoir.
In this study, we compared the pre-drill column heights derived from seismic amplitudes and STAR with well results at XY-South Prospect for various reservoir sands. The study showed in general that the actual HC columns were consistently smaller than the prognosed results. A postdrill HC column height estimation study was carried out to address the under estimation of column heights. Findings indicate that the HC columns are strongly dependent on the fluid phase and gradient used. The predrill STAR estimate was for oil with a default gradient of 0.35psi/ft. However, the actual fluids found were more gas rich and the oil had lower gradients than the STAR default values, hence shorter predicted columns.
Also a comparison of the amplitude-based versus STAR-based contact predictions was made on this XY-South prospect. Predrill STAR predicted contacts are very close to the predrill amplitude estimated contacts (differences are between 12 to 20ft). Thin oil rims cannot be resolved on the amplitude depth plots (GOC vs OWC).
Chronic Unease: A Sign of a Good Safety Culture
Authors: Ehi Ataga 
Published: July 2014

Abstract
Oil and gas exploration and development is a very hazardous business and this is as a result of the volatile/inflammable property of hydrocarbons and the effect such an incident can have on the people, our asset, the environment and the reputation of the company we work for. There have been remarkable improvements in the industry in general with regards to safety over the last 25 years due to more focus on safety and improved processes but the fact that things haven't happened doesn't mean they never will. Every incident free day might increase the chance of one happening due to complacency, not being uneasy, and not thinking of improving safety, hence the need to demonstrate chronic unease. Chronic unease is being in a constant state of wariness towards hazards and risks in our work place, it means noticing those weak danger signals and responding to them in a much stronger way. Chronic Unease is a preoccupation with failure – mindful of our risk, resetting our tolerance towards risk and understanding that small failures are signs that something needs fixing. The call is to demonstrate chronic unease behaviors and make it a safety culture and this involves – Understanding that barriers and controls should be independent of each other, being on the look out for weak signals, being mindful of signals that tell us our barriers aren't strong, Inspection reports that are too clean with identical ticks also called traffic light reporting etc. In conclusion, Uneasy people are safer because: They recognize weak signals and are unafraid to do something about it even if it means raising a false alarm; They think things through slowly, thoroughly and realistically before acting; they don't take critical situations for granted and never jump to conclusions; Get the facts first and don't get complacent about risks. A safety culture is the most important reputation indicator in the oil and gas industry due to the long time taken to establish a company culture through hard experiences and lessons, and all of these can be destroyed with one accident. An improved and mature safety culture can prevent accidents and improve quality significantly, hence the need to demonstrate chronic unease behaviors.
Integrated Pore Pressure Prediction Using Seismic Velocity and Appraisal Well Data for a Virgin Reservoir Undergoing Depletion from Nearby Fields
Authors: Okpako Kelvin , Basak Prahlad , Abia Godwin , Odegbesan Seyi , Roya Simon 
Published: July 2014

Abstract
Nearby field production effects in field development is a key consideration in well design for safe well delivery and HSE considerations. Formation Pore Pressure Prediction (PPP) aims to identify and manage formation pressures with associated subsurface uncertainties/risks, and serves as input into well design and delivery. Reservoir injectivity, depletion from hydraulic communication with other reservoirs, and fault seal reactivation, amongst others are some of the common processes that could alter the in-situ pore pressures of virgin reservoirs. Thus planning a well where these subsurface uncertainties and more exist, would pose the challenge of quantifying the uncertainties and incorporating them into the well's PPP/design to allow for safe well operations, protecting lives, properties, and the environment.
This was the case of a development oil well (Oganza-015), planned to be drilled into the virgin and appraised block-B of the Oganza Field in the Niger Delta. Regional (map and correlation) and Production data from the field suggest that some of the reservoirs are in hydraulic communication with two producing nearby fields (Okpokiri and Ekunam) via a common aquifer, and as such would have seen some level of depletion due to production from these nearby fields. Other identified subsurface uncertainties in this block include, the reservoir structural tops and bases, fluid contacts (original vs. present), fluid type and density/gradient, connectivity between blocks (by aquifer or hydrocarbon zones), fault extension and transmissibility, strength of aquifer/gas cap, etc. Related risks with drilling through these depleted reservoirs include; mud losses that could lead to a well control situation, differential sticking and loss of drill string with BHA, casing burst, and other reservoir management issues.
An integrated approach via quantitative seismic interpretation, appraisal, development, and production data analyses in PPP for the planned Oganza-015 well was adopted to manage the aforementioned uncertainties and associated risks. This incorporated all available seismic (seismic velocity), geological (maps and sand correlation), petrophysical (porosity sensing well logs, fluid type and gradients), reservoir engineering (RFT, PVT), drilling (mud weights, drillability exponent), and production (BHP) data.
This work further demonstrated that the Oganza field is hydrostatic in-situ with average pressure gradient of 0.433psi/ft, and that slight depletion (ca. 0.425psi/ft.) at some deeper reservoir levels has occurred. These and other subsurface uncertainties were taken into consideration in the PPP that has been put forward for a safe well design and delivery.
In this paper, a PPP workflow for design and safe delivery of development wells targeting and/or traversing virgin reservoirs under depletion using seismic velocity and appraisal well data is presented.
Impact of Language Barriers on Complications and Mortality Among Immigrants With Diabetes: A Population-Based Cohort Study
Authors: Okrainec Karen , Booth Gillian L. , Hollands Simon , Bell Chaim M. 
Published: July 2014

OBJECTIVE
Our objective was to examine the effect of language barriers on the risk of acute and chronic complications of diabetes and on mortality among immigrants.

RESEARCH DESIGN AND METHODS
Linked health and immigration databases were used to identify 87,707 adults with diabetes who immigrated to Ontario, Canada, between 1985 and 2005. These individuals were included in our cohort and stratified by language ability at the time of their immigration application. Primary end points included: one or more emergency department visit or hospitalization for 1) hypo- or hyperglycemia, skin and soft tissue infection, or foot ulcer and 2) a cardiovascular event or death between April 1, 2005, and February 29, 2012.

RESULTS
Our cohort was followed up for a median of 6.9 person-years. Immigrants with language barriers were older (mean age, 49 ± 15 vs. 42 ± 13 years; P &lt; 0.001), more likely to have immigrated for family reunification (66% vs. 38%, P &lt; 0.001), had less education (secondary school or less and no education, 82% vs. 53%; P &lt; 0.001), and a higher use of health care (mean visits, 8.6 ± 12.1 vs. 7.8 ± 11.2; P &lt; 0.001). Immigrants with language barriers were not found to have higher adjusted rates of diabetes complications (acute complications: hazard ratio [HR] 0.99, 95% CI 0.93–1.05; cardiovascular events or death: HR 0.95, 95% CI 0.91–0.99). Significant predictors included older age, being unmarried, living in a rural neighborhood, and having less education. Immigrants who were older (≥65 years) and who had arrived through family reunification had a lower risk of cardiovascular events or death (HR 0.88, 95% CI 0.81–0.96).

CONCLUSIONS
In a heterogenous immigrant population with universal insurance, language barriers were not found to increase the risk of diabetes complications. However, their effect may vary based on age at time of landing, education level, marital status, and neighborhood of settlement.
Diagnosis and management of Enterococcus spp infections during rehabilitation of cold-stunned Kemp's ridley turtles (Lepidochelys kempii): 50 cases (2006–2012)
Authors: Innis Charles J. , Braverman Hillary , Cavin Julie M. , Ceresia Michelle L. , Baden Lindsey R. , Kuhn Duncan M. , Frasca Salvatore , McGowan J. Patrick , Hirokawa Keiko , Weber E. Scott , Stacy Brian , Merigo Constance 
Published: July 2014

Abstract
Objective—To evaluate clinical data for cold-stunned Kemp's ridley turtles (Lepidochelys kempii) with Enterococcus spp infections during rehabilitation.
Design—Retrospective case series.
Animals—50 stranded cold-stunned Kemp's ridley turtles hospitalized between 2006 and 2012.
Procedures—Medical records for turtles from which Enterococcus spp were isolated were reviewed retrospectively, and clinical data, including morphometric data, body temperature at admission, physical examination findings, antimicrobial medication history, history of medications administered IV, environmental data, day of diagnosis, clinical signs at diagnosis, microbiological testing results, sources of positive culture results, hematologic and plasma biochemical data, cytologic and histopathologic results, radiographic findings, antimicrobial treatments, time to first negative culture result, treatment duration, results of subsequent cultures, and case outcome, were collated and analyzed.
Results—Enterococcus spp were isolated from bacteriologic cultures of blood, bone, joint, and respiratory tract samples and a skin lesion, with supporting evidence of infection provided by histopathologic, cytologic, and radiographic data. Positive culture results were associated with clinical problems such as lethargy, anorexia, and lameness. Most (34/43 [79%]) turtles for which an antemortem diagnosis was made survived with treatment and were released into the wild.
Conclusions and Clinical Relevance—Cold-stunned Kemp's ridley turtles may be affected by serious Enterococcus spp infections during rehabilitation. Recognition and treatment of these infections are important for successful rehabilitation.
Spawning Behaviour and the Softmouth Trout Dilemma
Authors: Esteve Manu , McLennan Deborah Ann , Zablocki John Andrew , Pustovrh Gašper , Doadrio Ignacio 
Published: July 2014

Abstract
Morphological, ecological and molecular data sets do not completely agree on the phylogenetic placement of the softmouth trout, Salmo (Salmothymus) obtusirostris (Heckel). Molecules posit that softmouths are closely related to brown trout, Salmo trutta L. while some morphological, ecological and life history traits place them in the most basal position of the Salmoninae subfamily between grayling (Thymallus) and lenok (Brachymystax). Here we add an additional source of data, behavioural characters based on the first reported observations of softmouth spawning. During spawning softmouth females present three important behaviours not found in the other Salmo members: they continually abandon their nests, rarely staying on them for periods over nine minutes; they expel different batches of eggs at the same nest at intervals of several minutes; and they do not cover their eggs immediately after spawning. These three behaviours are intriguing for two reasons: 1) they are possible homologous to behaviours found in grayling females; 2) when coupled to the nest digging behaviour-widespread in all the salmonines, including softmouths, they seem to be mal-adaptive.
Efficient Data Transfer by Mobility Adjustment Algorithm for Clustered Mobile Ad-Hoc Networks
Authors: Alagiri I. , Madhuviswanatham V. , VenkataKrishna P. 
Published: July 2014

Abstract
Mobile Ad-hoc NETwork (MANET) is a prevalent deployable network for easy plug-in and it is widely applied for many real time scenarios. Clustering is a well known solution for efficient communication among nodes with least control overheads. The communication link breaks between nodes when a node moves beyond the transmission range of another node because of mobility. Frequent link breaks happen because of nodes mobility which cannot be controlled without increasing the network control overheads. The authors propose an Mobility Adjustment Routing (MAR) routing algorithm for establishing a stable path between the source and the destination. In this approach the choice of cluster heads based on the smallest weight age, node mobility and remaining battery power are used as a metric for weight computation. The cluster head and the gate way nodes forward RREQ packets to set up a path between the source and the destination which proves efficient communication, before forwarding a RREQ packet cluster the head/gateway node compares its mobility value with RREQ and updates the least value in RREQ. The destination node advertises the least mobility value to the remaining nodes in the path with the help of RREP packet, therefore stable paths are found without increasing the network control overheads. The simulation results done with the help of network simulator 2 show that the algorithm proposed performs well even at higher traffic load compared to existing algorithms.
Actuarial Modeling of Life Insurance Using Decrement Models
Authors: Luptáková Iveta Dirgová , Bilíková Mária 
Published: July 2014

Abstract
The aim of this paper is to elucidate decrement models and their use in actuarial calculations in life insurance. The first part deals with the most often used decrement model, the mortality table. The second part gives an example based on a simple model to illustrate the creation of a multi-valued decrement table using the data from the single-value tables for a group of decrements and their use in insurance mathematical calculations.
Polyurethane Foams with Pyrimidine Rings
Authors: Kania Ewelina , Lubczak Jacek 
Published: July 2014

Abstract
Oligoetherols based on pyrimidine ring were obtained upon reaction of barbituric acid with glycidol and alkylene carbonates. These oligoetherols were then used to obtain polyurethane foams in the reaction of oligoetherols with isocyanates and water. The protocol of foam synthesis was optimized by the choice of proper kind of oligoetherol and synthetic composition. The thermal resistance was studied by dynamic and static methods with concomitant monitoring of compressive strength. The polyurethane foams have similar physical properties as the classic ones except their enhanced thermal resistance. They stand long-time heating even at 200°C. Moreover thermal exposition of foams results generally in increase of their compressive strength.
Determination of Chlorine Dioxide and Chlorite in Water Supply Systems by Verified Methods
Authors: Tkáčová Jana , Božíková Jarmila 
Published: July 2014

Abstract
This work is dedicated to the development and optimization of appropriate analytical methods for the determination of chlorine dioxide and chlorite in drinking water in order to obtain accurate and correct results in the quality control of drinking water. The work deals with the development and optimization of a method for the determination of chlorine dioxide using chlorophenol red. Furthermore, a new spectrophotometric method for the determination of chlorite via bromometry using methyl orange was developed, optimized and validated. An electrochemical method for the determination of chlorite by flow coulometry was also developed, optimized and validated.
Characterization of Frictional Stressed White Etching Layers out of Cutting Tools by Means of Transmission Electron Microscopy (TEM)
Authors: Walzhofer F. , Linz M. , Steiger-Thirsfeld A. , Bernardi J. , Badisch E. , Winkelmann H. , Gachot C. 
Published: July 2014

Abstract
White etching layers have been found at the surface of water submerged cutting tools and have been analyzed by transmission electron microscopy (TEM). For high resolution investigations, samples had been prepared by sandwich and lift-out preparation. The investigations have shown a grain refinement at the surface. The origin martensitic microstructure is transferred into a nano-crystalline microstructure of domain sizes down to 50 nm. The crystallographic structure was identified by electron diffraction as martensite. Moreover, the depth of the grain-refined layer is not as deep as the white etching phenomenon as it is found in conventional optical micrographs. Thus, the white etching layer is not only caused by the grain refinement.
Comparison between AMSR-E ASI sea-ice concentration product, MODIS and pseudo-ship observations of the Antarctic sea-ice edge
Authors: Zhao Xi , Su Haoyue , Stein Alfred , Pang Xiaoping 
Published: July 2014

AbstractThe performance of passive microwave sea-ice concentration products in the marginal ice zone and at the ice edge draws much attention in accuracy assessments. In this study, we generated 917 pseudo-ship observations from four Moderate Resolution Imaging Spectroradiometer (MODIS) images based on the Antarctic Sea Ice Processes and Climate (ASPeCt) protocol to assess the quality of the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) ARTIST (Arctic Radiation and Turbulence Interaction STudy) Sea Ice (ASI) concentrations at the ice edge in Antarctica. The results indicate that the ASI pixels in the pseudo-ASPeCt observations have a mean ice concentration of 13% and are significantly different from the well-established 15% threshold. The average distance between the pseudo-ice edge and the 15% threshold contour is ~10 km. The correlation between the sea-ice concentration (SIC), SICASI and SICMODIS values at the ice edge was considerably lower than the high coefficients obtained from a transect analysis. Underestimation of SICASI occurred in summer, whereas no clear bias was observed in winter. The proposed method provides an opportunity to generate a new source of reference data in which the spatial coverage is wider and more flexible than in traditional in situ observations.