bluuebunny/crossref_metadata_2025 huggingface dataset:
‘Parabiotic Evolution’: From Stochasticity in Geochemical and Subsequent Processes to Genes, Genomes and Modular Cells
Authors: Egel Richard
Published: October 2017

This article reevaluates the Woesean concept of crossing a ‘Darwinian threshold’ from pre-genomic communality, as prevailing in an ancestral ‘progenote’ state, to vertically stable lineages of autonomous and self-similar cells. This transition from collective trunk-line evolution to Darwinian speciation is dependent on the generation of modular organismal genomes. The same general principle should be valid at subcellular levels, allowing the emergence of semi-autonomous genomic agents, such as viruses and plasmid-carrying endogenous vesicles with organelle-like properties. As compartmentalized agents of endogenous nature could start with smaller genomes than those required for fully autonomous cells, it is conjectured that stable subcellular lineages emerged earlier than their cellular counterparts. Referring to the recent ‘pre-endosymbiont hypothesis’, it is proposed that free-living bacteria (the first ‘prokaryote’ cells) arose by ‘lineage escape’ from plasmid-bearing organelle-like compartments, evolving inside the internally complexifying ‘paracells’ of the progenote community. The double-membrane envelopes of diderm bacteria may have resulted from cell-biological processes facilitating cellular lineage escape. The later emergence of archaeal cells (resembling bacteria in ‘prokaryote’ appearance with unichromosomal genomes) and eukaryotic organisms (with compartmented cells and multichromosal genomes) can also be interpreted in terms of this modified progenote hypothesis. Conceivably, the multichromosomal genomes of eukaryotes were bundled in endogenous nuclear compartments to organize a ‘nuclear-cytoplasmic lineage’, which became vertically stable by perfecting mitosis/meiosis-like divisions and yet retained some intra-species population confluence by sexual division-fusion cycles.
A Method to Count Olive Trees in Heterogenous Plantations from Aerial Photographs
Authors: Chemin Yann H. , Beck Pieter S.A.
Published: October 2017

Olive trees have been of economic and cultural value since pre-Roman times, and continue to dominate landscapes and agriculture in many mediterranean regions. Recent mass losses of olive trees in Southern Italy due to an exotic plant pathogen highlight the need for methods that to monitor the olive trees in a landscape or region operationally. Here, we develop a method for counting olive trees from aerial photographs and test it in areas with a high diversity of olive tree ages, sizes, and shapes. This heterogeneity complicates tree counting as centennial trees often have crowns that are split into multiple segments, resembling multiple crowns, while nearby crowns often form a semi-closed canopy comprising multiple trees. Comparisons with reference counts in two 20 ha sites and over three different years indicate the automated counts tend to be reasonably accurate (median error 13%, n = 6), but heavily influenced by a few olive orchards with particularly high planting densities and a relatively closed canopy in which distinguishing individual trees is challenging. Overall, the algorithm estimated tree densities well (counting 82 to 109 trees/ha versus 87 to 104 trees/ha in the reference counts), indicating the method is suitable to track the number of olive trees over large areas.
Carta al Editor
Authors: Fernández Alba Juan Jesús
Published: October 2017

Aclaración a la Carta al Editor enviada por el Prof. Victo Patricio Díaz Narváez.En dicha carta se alude al artículo Fernández JJ,  Paublete MC, González  MC, Carral F, Carnicer  C, Vilar A. et al. Sobrepeso y obesidad maternos como factores de riesgo independientes para que el parto finalice en cesárea. Nutr Hosp. 2016; 33(6):1324-1329, publicado por nuestro grupo de investigación en su revista.Dado que en dicho escrito se sugiere el uso inadecuado de la matemática para extraer conclusiones científicas, realizamos un razonamiento de nuestra metodología, aportamos los coeficientes a los que alude y completamos la información aportada por dicho Prof.
Effects of Adhesives on Reliability in Interfacial Strength Evaluation Method for Plasma-Sprayed Hydroxyapatite Coating
Authors: Otsuka Yuichi ,   Nagaoka University of Technology 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan, Hiraki Yoshihisa , Hakozaki Yuki , Miyashita Yukio , Mutoh Yoshiharu
Published: October 2017

The purpose of this study is to evaluate interfacial strength of plasma-sprayed HAp coating by using more general adhesives. Plasma-sprayed HAp coating has been applied to bond bones with the surfaces of artificial hip joints. However, HAp coating is subjected to crack or delamination by mechanical loading. Conventional standard codes for measurement of interfacial strength of calcium phosphate coating determine the use of a specific adhesive irrationally. Our group previously proposed pre-immersion treatment process in preparation of interfacial testing specimens in order to obtain valid value of interfacial strength. However, the type of the adhesive was for medical purpose and not general one. To widen applicability of the proposed method, a selection policy of adhesive is indispensable. Metal Lock Y610 (ML adhesive) was selected as one of general adhesives. Interfacial strength tests by using ML adhesive were conducted. The results of interfacial strength test were compatible with the one reported by previous study, which suggest that the selection of general type of adhesive was successful. Raman spectroscopy analyses were also conducted to confirm a suppressed infiltration of ML adhesives.
Pengembangan Multimedia Caregiver Untuk Peningkatan Pelayanan Lansia
Authors: Rohaeni Neni , Ningsih Mirna Purnama , Jubaedah Yoyoh
Published: October 2017

Penelitian ini dilatarbelakangi oleh tuntutan kompetensi yang harus dikuasai oleh mahasiswa dan lulusan Program Studi PKK yang dirumuskan dalam Kerangka Kualifikasi Nasional Indonesia (KKNI), sebagai calon guru SMK dan konsultan keluarga serta konsultan pekerja sosial khususnya pada pendampingan lansia sebagai Caregiver. Penelitian ini bertujuan mengembangkan Multimedia Caregiver Untuk Peningkatan Pelayanan Lansia. Pemecahan masalah dilakukan dengan menggunakan pendekatan Research and Development, melalui tahapan: (1) Studi Pendahuluan, (2) Pengembangan Model dan (3) Validasi Model. Studi Pendahuluan dilakukan kegiatan: (a) Studi literatur berkaitan dengan masalah penelitian, (b) Identifikasi karakteristik multimedia Caregiver untuk Peningkatan Pelayanan lansia, (c) Merancang Story Board Multimedia Caregiver untuk Peningkatan Pelayanan Lansia.Tahap pengembangan model akan dilakukan: (a) Pembuatan Multimedia Caregiver.(b) Ujicoba Multimedia Caregiver pada Pelayanan Lansia, (c) Evaluasi dan penyempurnaan.Tahap validasi model akan dilakukan: (a) Uji validasi modelmelalui expertjudgement ahli, (b) Uji validasi model secara empirik, (c) Evaluasi dan penyempurnaan model hingga menghasilkan model final. Penelitian ini ditargetkan memiliki luaran sebagai berikut: (1) Multimedia Caregiver untuk Peningkatan Pelayanan Lansia. (2) HKI berupa Hak Cipta Video Senam Lansia
Recomendaciones para prevenir la transmisión de Mycobacterium abscessus en los procedimientos odontológicos
Authors: Martínez-Menchaca Héctor R , Bonasso-Byrd Patricia A , Rivera-Silva Gerardo
Published: October 2017

[No disponible]
Sífilis congénita en el estado de Baja California
Authors: Conde-González Carlos Jesús
Published: October 2017

Señor editor: He leído con interés la comunicación intitulada “Prevalencia de sífilis congénita en tres hospitales públicos de Baja California, México, 2012-2015”, de la autoría de Arellano-Estrada y colaboradores, publicada como carta al editor en Salud Pública de México.1 Dado el título del trabajo y sin demeritar la valía del estudio realizado, hago notar tanto a los autores como a los editores la omisión cometida al no proporcionar el dato de la prevalencia de sífilis congénita durante los años explorados en los hospitales del gobierno de la entidad federativa, en Tijuana, Playas de Rosarito y Tecate...
Impact of Slow and Fast Warm-Up Rates on Cement Sheath Integrity in SAGD Wells: Using Dynamic Flow Simulators for Early Time Analysis
Authors: Nascimento C. M. , Demirdal B.
Published: October 2017

The original viscosity of the oil in place is greater than 1,000,000 centipoises in most cases in Western Canada. As a result, steam assisted gravity drainage (SAGD) is a widely used thermal recovery method to produce bitumen reserves for the last 10-15 years. SAGD involves drilling two horizontal wells (one on top of each other roughly 5 meters) apart and injecting steam from the top well (called "injector") to reduce the viscosity of oil in place by heating and produce the flowing oil from the bottom one (called "producer").

Initially, there is very little to no pressure communication between the injector and producer since the bitumen is in solid state. As a result, in order to initiate communication between the wells so steam injection can penetrate into the reservoir to heat the rock and the fluids, both wells were circulated with steam and this phase is called "circulation". During circulation, steam is injected to the wells through long tubing and returns are received back through short tubing. In addition to be quite critical to the overall production performance of the reservoir, circulation phase has a critical impact on the integrity of the well since during this phase the well was introduced to heating for the first time. Considering the fact that steam is being injected in a cold well, thermal loading impacts on casing and cement are expected to be the highest during earlier times of circulation. While injecting steam at higher rates as early as possible has operational benefits, effects of such practice on zonal isolation should be evaluated in detail.

A well operated by Devon in Jackfish field was used for this purpose and a dynamic flow simulator was modelled to investigate the impact of slow (going from 1 ton/hr to 5 ton/hr in 5 days) versus fast warm-up during early stages of circulation phase on cement sheath. Field data captured by distributed temperature sensing system (DTS) was used to validate the model and comparison on cement heating rate at different depth intervals during slow and fast warm up cases were made to determine at what depths and durations the heating rates of cement are different between the two cases.

The combination of the field results and simulation enabled to determine the critical time frame where different circulation strategies have the highest impact on cement heating rates. The simulation results also provided insight on transient temperature distribution across wellbore and near wellbore during early times of circulation.
Design Optimization of Slotted Liner Completions in Horizontal Wells: An Analytical Skin Factor Model Verified by Computational Fluid Dynamics and Experimental Sand Retention Tests
Authors: Mahmoudi M. , Nejadi S. , Roostaei M. , Olsen J. , Fattahpour V. , Lange C. F. , Zhu D. , Fermaniuk B. , Nouri A.
Published: October 2017

The term skin is used to describe pressure drop caused by a flow restriction near the wellbore. The skin factor of wells completed using slotted liners can be explained by a number of phenomena including: the flow across the slots, flow convergence towards slots, near wellbore permeability, and occlusion of liner open area due to corrosion and scale deposition. This paper introduces an analytical skin model for the slotted liner, which incorporates these phenomena, and can be used to optimize the slotted liner design. The introduced analytical model was verified by physical and Computational Fluid Dynamics (CFD) models.

The proposed analytical skin factor model for slotted liners is based on slot width, slot density, the spatial distribution of slots, and near-liner permeability. The model also incorporates partial plugging of slots. The model is validated using experimental Sand Retention Testing (SRT) data. A series of SRT experiments were conducted at different flow rates for two Particle Size Distributions (PSD) from the McMurray Formation in Northern Alberta. The experiments were also modeled by the CFD to better understand the flow dynamic near the liner.

Results of the analytical model and experimental tests were generally in agreement. However, results of the analytical model deviate from experimental tests for narrow slots and high flow rates. In these cases, the analytical model predicts smaller skin than the experimental tests. For cases related to narrow slots and higher velocity the pore plugging close to the liner is significant which was not modeled in the analytical model. Moreover, for very fine sand (low permeability) sand-pack the deviation from the experimental results is higher in comparison with medium uniform sand (higher permeability) sand-pack. CFD simulations showed the effect of the slot width on the depth of the convergence zone, which is not included in the analytical model. Since the analytical model follows the experimental results for common flow rates in thermal production, the model could be used to assess the skin for different possible designs and choose the best slot specifications that minimize the skin.

This paper presents the details of an analytical model for the skin factor verified by experimental data and CFD simulation. This analytical model can be used to optimize the liner specification for the best flow performance. This paper also outlines the limitations of the analytical models for calculation the skin/pressure drop.
Effective Application of Combination Technologies and Processes for Successful SCP Well Abandonment
Authors: Amanov Bauyrzhan , Aidoo Ato , Khouzin Azat , Lommers Cas , Viti Massimo , Valiakhmetov Rustem
Published: October 2017

This paper discusses the effective application of a Combination Technologies and Processes that allowed successfull abandonment of wells with Sustained casing pressure (SCP), on the Karachaganak field. The planning and execution processes of SCP elimination are examined.

Previous experience in the abandonment of wells with SCP using existing procedures and methodologies for cement and bridge plug placement, on the Karachaganak field, has not always been successful. In some instances sustained casing pressure reappeared, resulting inadvertently in re-entry for intervention.

In 2015 several SCP wells were successfully abandoned using a combination of technologies. The processes will be described in detail in this paper, including:

Image log to enable selection of the interval for section milling Section milling - removal of a section of casing Under reaming to remove remaining cement sheath from the wall of the outer casing Inflatable Bridge Plug - mechanical barrier for placement in the opened window interval.

Karachaganak is a giant gas-oil condensate field with presence of H2S and CO2. Due to that, during well abandonment SCP issue must be eliminated to comply with Republic of Kazakhstan regulation and oil industry standards. SCP, regardless of its value can pose hazards not only to the environment but also be a source of formation of man-made deposits. To ensure industrial safety, environmental expediency and to meet regulatory requirements, the wells with SCP require regular monitoring.

The above mentioned technologies and processes were successfully implemented in wells abandonment and elimination of SCP on wells in the Karachaganak field. All wells were monitored throughout the year, considering the huge variance in the severe ambient weather conditions throughout, and it was proved that no issues with SCP have reoccurred so far.

This paper provides well construction and integrity teams’ information on a solution that could be used in many other wells around the world. The benefits achieved by the Kazakhstan operator open up opportunities to solve SCP problems and prevent future intervention.
The Role of Internal Diameter Tolerances in Interpreting Casing Inspection Logs
Authors: Atakishiyev Fuad , Alkhasov Emin , Schoepf Virginie , Zett Adrian
Published: October 2017

Multi-finger caliper tools are widely used for inspection of casing inner wall condition, particularly for determining wear, corrosion, deformation and scaling. The maximum pipe wall penetration, and hence metal loss, inferred from this method is greatly dependent on the casing inner diameter value (provided by casing manufacturer) used as a reference. Evidence of overestimated casing wear, including new completions, has raised the question around the validity of such interpretations.

Most of the casing is manufactured to API 5CT (ISO 11960) standard. The manufacturer‘s specification has an associated tolerance on casing outer diameter and thickness that is then used in the multi-finger caliper logs interpretation. The tolerance for casing with outer diameter (OD) greater or equal than 4.5″, is between -0.5% and +1% of OD. The pipe wall thickness tolerance ranges between manufacturer's nominal thickness and 12.5% metal loss.

The calculation of casing internal diameter (ID) tolerance is a difficult task as this is controlled by the casing mass tolerance which in practice is not easy to measure. To overcome the challenge, we implemented a new approach of calculating the minimum and maximum casing inner diameter and then using the ID tolerance as a reference for multi-finger caliper logs interpretation.

This approach has been tested with field data, and shows good correlation to actual casing inner diameter measurements performed at surface and is used as a baseline for new casing strings.

This paper will describe in detail the approach taken and compare the difference between interpretation outcomes with and without using the casing inner diameter tolerance. The benefits of calculating casing inner diameter tolerance and applying it to multi-finger caliper log interpretation results will be backed up with evidence from field log data acquired in ACG.
The Comparison of Inflow Profiling Technologies for ERD Wells Including PLT, Fiber Optics DTS, Stationary Chemical Tracers: A Case Study from the Caspian offshore Yuri Korchagin Field in Russia
Authors: Shtun S. Y. , Senkov A. A. , Abramenko O. I. , Matsashik V. V. , Mukhametshin I. R. , Prusakov A. V. , Nukhaev M. T.
Published: October 2017

The purpose of this paper is to compare the permanent monitoring systems based on optical fiber systems and intelligent chemical tracers. This analysis was carried out based on an operational assessment of similar systems for permanent monitoring of horizontal wells in the Yuri Korchagin oilfield for 3 years in various regimes of operation.

The paper discusses the main advantages and limitations of these systems and provides their comparison to conventional production logging tools (PLTs).
Application of Experimental Design for Probabilistic IOR Evaluation at Korolev Field
Authors: Galimzhanov Saken , Iskakov Elrad , Levchenko Pavel , Turmanbekova Aizhan , Zhumagulov Kanat
Published: October 2017

Tengizchevroil (TCO) is the biggest operator in Kazakhstan developing two world's deepest supergiant oilfields - Tengiz and, its satellite field, Korolev. With over 20 years of oil production at TCO, reservoir pressure has been declining and is approaching bubble point pressure. In order to arrest the declining pressure trend and extend oil production plateau, TCO is evaluating Improved Oil Recovery (IOR) opportunities, including potential Waterflood in Korolev field.

Accurate Waterflood evaluation requires improved characterization of the main uncertainties impacting ultimate recovery under IOR processes. Therefore, we built next-generation Korolev reservoir model (SIM15K) which incorporates results of the latest characterization efforts based on the latest wide- azimuth 3D seismic survey. This work led to updated Korolev depositional model, which helps to understand the links between geological settings and fracture occurrence. In conjunction with the first implementation of Dynamic Data Integration workflow, this resulted into updated Low-Mid-High fracture models - one of the main factors controlling Waterflood performance in naturally-fractured reservoirs.

This paper focuses on Brownfield Experimental Design (ED) of Korolev field, which is specifically designed to provide an estimate of IOR Incremental Recovery. We identified 23 main uncertainty parameters for each Low-Mid-High Fracture models. The Brownfield ED was run with two development scenarios: Primary Depletion and Waterflood to get probabilistic assessment of Incremental Waterflood Recovery. Overall 803 cases were required for each fracture model and development scenario to generate good quality proxies for cumulative recoveries and History-Match error. Those proxies were used to sample the entire space of uncertainties and define P10/50/90 targets.

As a result of robust Brownfield ED, we selected P10/50/90 models to capture both range in Incremental Waterflood Recovery and Ultimate Recovery under Primary Depletion. The underlying uncertainty parameters for the final model selection were picked based on their relative impact on the objective functions. Currently, the new SIM15K model is being used for Korolev Waterflood evaluation and optimization, Reserves estimation, existing infrastructure optimization and future projects design.
An Integrated Pore Scale and Reservoir Modeling for Near Miscible Three-Phase Flow WAG Flooding Reservoir
Authors: Gibrata Muhammad A , Hashem Mohamed
Published: October 2017

Reliable of pore scale and reservoir modeling in reservoir with water alternating gas (WAG) flooding is challenging and important for getting an accurate reservoir characterization, enhanced oil recovery (EOR) and reservoir management. Inaccurate characterization and modelling of these reservoir properties and fluid will lead to high uncertainty of reservoir characterization, minimum oil recovery and reservoir management concerns. Hence it is useful to predict and assess effects on pore-scale and EOR of field scale.

The comprehensive pore-scale and reservoir modeling approach is required by the integration of various sources such as those from petrophysical, geological, reservoir and production data. Utilize the 3D network structure of representative reservoir rock properties. In prediction and guide SCAL based; investigation the effects (sensitivity) of interfacial tensions, contact angles, wettability, spreading coefficient, balance of viscous and capillary forces into miscibility on the oil layers between gas and water in a fully interconnected three-phase flow pore-network model. Utilize thermodynamic criteria for rock properties and oil layers, which affect the oil relative permeability for accurate prediction of residual oil and maximize oil recovery.

I have used an integrated pore scale and reservoir models workflow: establish pore network model, validate with SCAL, up scale to well logs, utilize formation pressure/sampling/testing and combine with structural data of geology-seismic and perform history match of the reservoir dynamic modeling. The effect of balance of capillary and viscous forces in pore scale have been evaluated in the research. It has provided a reliable properties for a reservoir dynamic model.

In the research, I have used similar range of reservoir and fluid properties such as pore throat size in reservoir range for pore network model. I analyze pore scale and field scale oil recovery during WAG at immiscible and near miscible condition to generate the three phase relative permeability models (by modified weighting for near miscible). The current simulations at the reservoir scale shows that the highest oil recovery for the water-wet is obtained by injecting near miscible gas. Recovery increased by over 10% during WAG injection in agreement with typical values on SCAL and pore network models.

The comprehensive approach of near miscible three phase flow WAG in pore network model, core-logs validation and the reservoir model are important in reservoir modelling. The integration is used for getting an appropriate relative permeability, capillary pressures and water saturation in near miscible Gas and Water Alternating Gas (WAG) flooding of reservoir. Thus it can give an accurate and robust of reservoir characterization, maximize oil recovery and optimum reservoir management.
An Evaluation of Microbial Flooding for Enhanced Oil Recovery, Fuyu Oilfield, China
Authors: Jinfang Wang , Zhengmao Wang , Jun Tian , Chengfang Shi , Jian Gao
Published: October 2017

This paper depicts the laboratory results as well as reservoir surveillance and well production performance of microbial flooding in Fuyu oilfield, China. A four-spot water flooding has been applied from 1973, and various measures to increase production has been implemented since 1981. However, 1/3 non-absorbing reservoir and the invalid circulation of injection water lead to low production rate, high water cut, big flooding difference and low sweep efficiency.

To reduce water channeling, the Microbial Enhanced Oil Recovery (MEOR) test was initialed in Fuyu oilfield, China, in 1992. A microorganism named CJF-002 fed on nutrient was discovered as huff-puff test from 1996~2001. To replace the nutrient with high cost, a new nutrient was developed, using cornstarch as main raw material from 2002~2004. Furthermore, multi-slug microbial flooding was conducted at 22 injection-production well groups in 2005. The cell count of CJF-002 was more than 10^7cells/ml, and injection pressure less than 10MPa. The concentration of CJF-002 and crude oil composition in the sample was analyzed in laboratory before and after MEOR. Moreover, injection profiles monitoring and tracer tests were compared. Finally, the results of laboratory and tests were contrasted with well production performances.

The results observed microbial propagation under reservoir conditions with temperature 30°C and PH 7.5. The effect of injection profile modification was confirmed, which was helpful for plugging the high permeable zones and reducing water channeling. The agreement is obtained with the well production performances. Among them, 87.3% wells indicated a 50~100% oil production increase and an 8% water cut decrease. The water-drive laws curve shows the characteristic of drop, which means the improvement of development effect. The tests show that the composite indigenous microorganism oil displacement technology can enhance the oil yield of mature oilfield and recovery ratio, and it is an effective stimulation measures.
Modelling and Verification of Gravel Pack Treatments in ACG Field to Improve Sand Control Reliability
Authors: Hasanov Hikmet , John Colin , Wassouf Philip , Jain Samyak
Published: October 2017

Proper design, installation and evaluation of sand control completions is vital for ensuring sand control integrity and mitigating against production deferrals due to sanding events. This is becoming increasingly important in the ACG Field, located offshore Azerbaijan, where wells require gravel pack completions with shunt tube technology and narrow operating windows between reservoir and fracture pressures. However, due to the lack of suitable commercially available software and a standardized workflow, gravel pack operations have been designed and evaluated using a combination of customized spreadsheets, historical data and software ported from other industry segments, none of which support the complex flow paths, conditions and range of technology utilized. While this did work, it was a time-consuming and inefficient process that required a number of assumptions and continuous data transfer which could allow for inconsistencies when applied at scale with an increasing number of users.

To improve and standardize the design and evaluation of wells in the ACG field, a novel, commercially available sand control software was introduced for performing pre-job modelling, on-the-job calibration and post-job analysis in an integrated workflow for all stages of the sand control operation including wellbore displacements, step rate tests, gravel pack and reverse out. The software supports all common sand control technologies and flow paths, enabling the determination of optimal completion and hydraulic configurations during planning, identification of potential issues and redesign of the treatment during installation, as well as automatic analysis of surface and downhole data for a more detailed understanding of downhole events and mechanisms during post-job evaluation.

This integrated workflow is presented using case studies from the ACG field to illustrate its application and benefits. The workflow is found to be simpler, more effective and more accurate than the techniques used in the past, enabling all necessary modeling to be quickly and easily performed in-house for improved planning and optimization of upcoming operations. Further, the automated analysis of surface and downhole gauge data enabled detailed evaluation to be completed in a timely manner which maximized the value of the acquired data and ensured lessons learned could be effectively implemented. Finally, the ability to directly compare simulated and actual treatment data allowed the engineers to calibrate and validate the model for more accurate modelling of future treatments.
A Pore Network Model for Studying Boundary Layer Effect on Fluid Flow in Tight Formation
Authors: Mingqiang Chen , Linsong Cheng , Renyi Cao , Chaohui Lv , Jiuzhu Wu , Hao Liu
Published: October 2017

Due to intensive heterogeneity and micro-nano-meter-scale pores in tight formation, flow mechanism differs significantly from that in conventional reservoirs. Therefore, the capability to simulate pore scale flow in tight formation is of great importance in many applications, such as oil extraction from tight reservoirs and accurate prediction of oil production. In this paper, a 3D random network model which can characterize the heterogeneity of tight formation is proposed. Based on the established network model, a flow mathematical model in consideration of boundary layer effect is developed, whereas parameters in boundary layer thickness formula are determined by Particle Swarm Optimization algorithm. Then, repeated iterations are used to solve the flow mathematical model until the relative error of pressure in each pore between two adjacent iterations arrives at the given error, which guarantees the accuracy of the simulation result. The result is then validated by micro-tube experiment. Furthermore, factors influencing pore scale flow in tight formation are studied. Results show that: as a result of boundary layer effect, absolute permeability is no longer a fixed value, it increases with the increase of pressure gradient and reaches a stable value when displacement pressure gradient is large enough. In low displacement pressure gradient, non-linear flow appears. As average coordination number increases, connectivity of tight formation becomes better, absolute permeability and velocity are larger at the same pressure gradient; When pore radius remains unchanged, as aspect ratio increases, throat radius becomes smaller, effective space for fluid flow is compressed, leading to smaller absolute permeability and velocity at the same pressure gradient; Change of 3D random network model size through varying throat lengths has little effect on pore scale flow; With the increase of fluid viscosity, boundary layer becomes thicker and the effective flow space grows smaller, resulting in lower permeability and velocity at the same pressure gradient. When displacement pressure gradient is large enough, absolute permeability tends to a stable value, which has nothing to do with fluid viscosity.
Risk and Uncertainty Assessment While Estimation of Reserves
Authors: Rahimov F. V. , Eminov A. Sh. , Huseynov R. M.
Published: October 2017

Risks are inherent practically in all sphere of oil and gas production: from geological exploration works on oil and gas to industrial development of reserves. But it is not enough to study only risks, we often face insufficiency of knowledge of variety of manifestations of geologic-geophysical trade properties of the studied object. It is especially important to consider risks and uncertainty at the initial stages of geological field works. Studying of geological risk, arising at estimation of oil reserves became a subject of our research. The work process was divided into some stages: 1) Choice of significant geological field parameters, 2) Definition of variable property manifestations factors of the studied geological field parameters, 3) Multiple modeling of the studied processes, 4) Creation of Tornado plot

For further work, the analysis of an assessment of risks at reserves estimation was chosen as a probabilistic method. It was chosen hypothetical fields which subcalculating parameters, were collected in tables

Using the data provided to the table, we make Tornado Plot extent of influence of geological risks is visually shown in the made matrix.

The made matrix reflects degree of risks in an assessment of subcalculating parameters and their influences on resultant indicators. The vertical scale reflects risk, which is classified on low, average, high. Using the results received in the analysis of uncertainty and a scale of influence of parameters on resultant indicators and a scale of level of risks, geological field parameters were located on the constructed matrix. From the received matrix, it is visible that among the taken parameters the greatest risk and high level of influence renders porosity. Therefore, the bigger attention at calculation of stocks and creation of geological and mathematical model has to be paid to this parameter.
Statfjord Field Late Life - Learnings from Planning to Current Depressurization Experience
Authors: Agaev G. S. , Lauritsen H. T. , Nesse O. B. , Frafjord D. , Stangeland E.
Published: October 2017

The production experience from the Statfjord Field on the Norwegian Continental Shelf is one of the greatest adventures in modern oil and gas history. After achieving very high oil recovery factor using a predominant drainage strategy with pressure maintenance by water and gas injection, the drainage strategy in the field has since 2007/2008 been changed to reservoir depressurization.

Prior to depressurization start-up, the field has produced about 652 million Sm3 (4.1 billion bbl) oil and 187 billion Sm3 gas. Currently, the field is producing at an oil rate of approximately 5 300 Sm3/d and a gas rate of about 11 million Sm3/d. Estimates indicate that successful implementation of the new drainage strategy will continue and lead to an ultimate oil recovery of higher than 67% and a significant additional gas production, as a result of the depressurization process. In addition, the field life will be extended from 2009 to 2025, and this will contribute to lifetime extension of the attached satellite fields.

The main purpose of this paper is to provide a description of the multidisciplinary approach used for evaluation and planning of the Statfjord Late Life (SFLL) with reservoir depressurization, share learnings from depressurization start-up and address challenges, uncertainties and opportunities.
Power Interconnection between two Existing Deepwater FPSOs - A Key Enabler for Production Increase
Authors: Leforgeais Bruno , Tayat Faradj
Published: October 2017

The first-ever power interconnection between Deep Offshore floating units, i.e Girassol and Dalia FPSOs, including retrofit of existing power generation and integration of an overall Power Management System, has enable the implementation of subsea multiphase pumping to activate the existing production loops.

Despite gas lift activation at riser base, the back pressure generated by pressure drop in the subsea network was limiting the liquid production of the high productivity wells. Providing a pressure boost in the production network using the subsea multiphase pumps enabled to lower the well head pressure, thus increasing production rates and ultimate recovery.

The paper will present the miscellaneous technical challenges that have been faced during the project development from the early design stage down to commissioning, start up and operation of both FPSOs as an integrated asset while maintaining and enhancing the full oil and gas production.

It will cover both surface and subsurface aspects with the design and implementation of power generation upgrade, electrical network modifications, overall power management system involving load sharing and load shedding as well as the interconnecting power cable with specific dynamic sections and the power supply and integration of the subsea multi phase pumps with an offset up to 18 km.
Practical Staged Implementation of Digital Field with Short Term Benefits
Authors: Gauder Denis , Koloskov Mikhail , Dmitry Sukhamera
Published: October 2017

The digital oilfield technology is typically associated with high level of field automation and instrumentation, as well as advanced petroleum engineering modelling.

This paper discusses the application of digital oilfield to large brown fields based on real, but anonymous cases, where the level of instrumentation is low, production models might not be available, and the local expertise might be limited.

In such situation, the principles of digital oilfield need to be adapted. This paper presents a staged implementation methodology, where the benefits and costs can be evaluated at every step of the project, allowing to build a system with the right amount of functionality and complexity.

The first step focuses on improving data quality, even if the data is captured manually, through automated quality checks and raising awareness during the data capture process. The second step focuses on automating routine tasks, such as reporting, leading to efficiency improvement, but also increased accuracy and traceability of the reported figures. The third step focuses on developing a production monitoring platform, allowing to perform exception-based surveillance, particularly important for large fields, as well as providing a single point of access for different disciplines, hence acting as a collaborative environment. At last, the model-based more complex workflows are discussed, such as virtual metering, production optimization and short-term production forecasting.

The main conclusion of this paper is that the Digital Oilfield can deliver value for brown fields, even if they are close to their life end. The relatively low cost of these solutions, and the immediate benefits they can provide makes it meaningful, even in a short-term perspective. A staged implementation lowers both the project risks and the required initial investment, while easing the adoption process by the users.

The main differences with application to green fields is an increased focus on data quality improvement, and a lower focus on models and complex engineering workflows. The surveillance platform should also focus more intensively on exception based surveillance, allowing to pre-process large amounts of data, rather than providing extremely fine detail.
PRODUÇÃO DE MINI-REPOLHO ORGÂNICO POR REBROTA SOB DIFERENTES NÍVEIS DE ADUBAÇÃO NITROGENADA
Authors: SOUZA JACIMAR LUIS DE , Favarato Luiz Fernando , Angeletti Maria Da Penha , Guarçoni Rogério Carvalho , Guimarães Gabriel Pinto , Peterle Gabriel
Published: October 2017

Uma das limitações à expansão do mercado de alimentos orgânicos no Brasil é a carência de estudos e tecnologias apropriadas a estes sistemas de produção. O mercado de mini-hortaliças no Brasil é crescente e de grande valor comercial. São produtos de elevado valor agregado, apresentam boa rentabilidade para pequenas escalas de produção e são menos suscetíveis a oscilações de preços do que as tradicionais. Na produção de repolhos orgânicos no Brasil, observa-se dificuldade em se obter um produto comercial com peso médio desejado pelo consumidor. O objetivo deste trabalho foi avaliar a eficiência agronômica e a rentabilidade econômica da produção de mini-repolhos por rebrota, em função de níveis de adubação nitrogenada residual. Esse trabalho foi desenvolvido na Unidade de Referência em Agroecologia do INCAPER, localizada no município de Domingos Martins-ES, a uma altitude de 950 m. O experimento foi disposto no delineamento blocos casualizados, com 4 repetições. Os tratamentos consistiram de adubações à base de composto com cinco níveis de N, com aporte de 0, 450, 600, 750 e 900 kg/ha de N-total. O número, peso médio, diâmetro médio, produção total e comercial de cabeças de repolho, tanto na produção primária quanto de mini-repolhos apresentaram uma elevação significativa com os níveis de nitrogênio. No maior nível de adubação nitrogenada, obtiveram-se rendimentos comerciais de 59.628 kg/ha de repolhos e de 30.575 kg/ha de mini-repolhos, proporcionando receitas líquidas de R$ 61.559,00 e R$ 141.815,90, respectivamente. Os mini-repolhos apresentaram pesos médios de 227g a 253g e diâmetros médios de 8,9cm a 10,2cm. A produção de mini-repolhos confirmou-se como alternativa de grande vantagem econômica, com gasto de mão-de-obra 34,0% e custo de produção 45,8% menores que a produção primária. A rentabilidade da produção de mini-repolhos foi 130% maior que a produção primária de repolho.
EXTRAÇÃO DE MINERAIS PELO CAPIM MARANDU FERTILIZADO COM ESTERCO DE GALINHA SEM E COM ESCARIFICAÇÃO
Authors: Eguchi Edson Sadayuki , Cecato Ulysses , Muniz Antonio Saraiva , Silva Samuel Laudelino da , Cruz Cristiano da
Published: October 2017

O uso de esterco de aves como fonte de nutrientes para pastagens em áreas degradadas é uma forma de destinação ambientalmente correta para reduzir os impactos ambientais. O objetivo do trabalho foi avaliarao final de um ano os minerais presentes e sua extração pelo capim Marandu fertilizado com esterco de galinha sem e com uso de arado escarificador no solo. O delineamento utilizado foi em blocos ao acaso com quatro repetições num arranjo fatorial 5 x 2, com cinco doses (0; 1,037; 2,074; 4,148; 6,222 Mg ha-1) de esterco, sem e com manejo de escarificação do solo e mais um tratamento adicional com adubação mineral NPK contidos em 2,074 Mg ha-1. Os cortes foram efetuados conforme interceptação luminosa de 95% do dossel na altura de0,15 m de resíduo. Na interação dose de esterco x manejo foi significativa para Ca, Mg, N, Cu e Zn, efeito de dose para P e sem efeito significativo para o K. Na extração anual a interação dose de esterco x manejo com escarificação houve ajuste linear, o N é o mineral de maior extração, seguido pelo K, Ca, Mg, P e Zn. Na extração mineral por corte efetuado com interação dose sem escarificação houve ajuste ao modelo linear decrescente entre as doses para o Ca, relacionado ao efeito da diluição em razão dos números de cortes. As fertilizaçõescom esterco de galinha e manejo do solo alteram a extração anual dos principais minerais relacionados.
ÓLEO ESSENCIAL DE PITANGUEIRA NA GERMINAÇÃO E SANIDADE DE SEMENTES DE VARIEDADES CRIOULAS DE FEIJOEIRO
Authors: Moura Gabriela Silva , Pietrobelli Silmara Rodrigues , Oliveira Idaiane Maria Ribeiro de , Oliveira Ivan Junior de , Franzener Gilmar
Published: October 2017

Diversos fitopatógenos podem afetar a sanidade de sementes de feijoeiro. Esse trabalho objetivou avaliar o efeito do óleo essencial (OE) de pitanga na incidência de patógenos e germinação de sementes defeijoeiro. O delineamento experimental foi inteiramente casualizado com cinco tratamentos e quatro repetições. O OE de pitangueira foi avaliado nas concentrações de 0; 0,05 %; 0,1%; 1% e 2%. As sementes foram imersas nos tratamentos por cinco minutos e acondicionadas em gerbox contendo papel de germinação. Foram avaliadas a porcentagem de germinação, plântula normal e anormal, comprimento de parte área e de raiz e massa da matéria fresca e seca. Também foi realizado teste de patologia de sementes com avaliação da incidência de fungos e bactérias. Foram utilizadas as variedades Mourinho e Rajado Vermelho.. Foram identificados nas duas variedades os patógenos dos gêneros Fusarium, Penicillium, Aspergillus, Colletotrichum, Bacillus e Xanthomonas. O OE de pitanga promoveu redução na incidência do fungo Fusarium na variedade Rajado Vermelho. Embora tenha apresentado efeito protetor, o óleo essencial, nas maiores concentrações, também apresentou efeito inibitório sobre o desenvolvimento de plântulas normais e sobre atributos do desenvolvimento das plântulas,indicando efeito fitotóxico nas maiores concentrações.
Oral Leiomyoma in an Adult Male: A Case Report
Authors: Nguyen Amanda Phoon , Frydrych Agnieszka M
Published: October 2017

Introduction:

Oral leiomyomas are rare, benign neoplasms of smooth muscle origin, presenting as a solitary, asymptomatic, nodular mass.

Case Presentation:

Here we present the case of a 54-year-old male with a lesion in the midline of his hard palate, which was diagnosed as a localized benign leiomyoma, along with a review of the recent literature.

Discussion:

Diagnosis of a leiomyoma must be based on the histopathological assessment of tissue as the clinical appearance is non-specific. The peak prevalence of head and neck leiomyoma is observed in the 4thand 5thdecade of life with uncertain gender predilection. Histological features include interlacing fascicles of smooth muscle small cells with eosinophilic cytoplasm. Complete excision is usually curative and recurrence is rare.

Conclusion:

Due to their rare nature, it is important that cases of oral leiomyoma can be reported in the literature to improve our understanding of this entity.
CD4 Lymphocyte Enumeration and Hemoglobin Assessment Aid for Priority Decisions: A Multisite Evaluation of the BD FACSPresto™ System
Authors: Thakar Madhuri , Angira Francis , Pattanapanyasat Kovit , Wu Alan H.B. , O’Gorman Maurice , Zeng Hui , Qu Chenxue , Mahajan Bharati , Sukapirom Kasama , Chen Danying , Hao Yu , Gong Yan , Indig Monika De Arruda , Graminske Sharon , Orta Diana , d’Empaire Nicole , Lu Beverly , Omana-Zapata Imelda , Zeh Clement
Published: October 2017

Background:

The BD FACSPresto™system uses capillary and venous blood to measure CD4 absolute counts (CD4), %CD4 in lymphocytes, and hemoglobin (Hb) in approximately 25 minutes. CD4 cell count is used with portable CD4 counters in resource-limited settings to manage HIV/AIDS patients. A method comparison was performed using capillary and venous samples from seven clinical laboratories in five countries. The BD FACSPresto system was assessed for variability between laboratory, instrument/operators, cartridge lots and within-run at four sites.

Methods:

Samples were collected under approved voluntary consent. EDTA-anticoagulated venous samples were tested for CD4 and %CD4 T cells using the gold-standard BD FACSCalibur™system, and for Hb, using the Sysmex®KX-21N™analyzer. Venous and capillary samples were tested on the BD FACSPresto system. Matched data was analyzed for bias (Deming linear regression and Bland-Altman methods), and for concordance around the clinical decision point. The coefficient of variation was estimated per site, instrument/operator, cartridge-lot and between-runs.

Results:

For method comparison, 93% of the 720 samples were from HIV-positive and 7% from HIV-negative or normal subjects. CD4 and %CD4 T cells venous and capillary results gave slopes within 0.96–1.05 and R2≥0.96; Hb slopes were ≥1.00 and R2≥0.89. Variability across sites/operators gave %CV <5.8% for CD4 counts, <1.9% for %CD4 and <3.2% for Hb. The total %CV was <7.7% across instrument/cartridge lot.

Conclusion:

The BD FACSPresto system provides accurate, reliable, precise CD4/%CD4/Hb results compared to gold-standard methods, irrespective of venous or capillary blood sampling. The data showed good agreement between the BD FACSPresto, BD FACSCalibur and Sysmex systems.