bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyzing Precision Agriculture Adoption Across the Globe: A Systematic Review of Scholarship from 1999 – 2020
Authors: Lee Chin-Ling , Strong Robert , Dooley Kim
Published: June 2021

Precision agriculture (PA) is a holistic, sustainable, innovative systems approach that assists farmers in production management. Adopting PA could improve sustainable food security and community economic sustainability. Developing an understanding of PA adoption attributes is needed to assist extension practitioners to promote adoption and better understand the innovation adoption phenomena. A systematic review of literature was conducted to investigate PA adoption. Thirty-three publications were examined, and four themes were found among the reviewed publications. The results were interpreted using Rogers’ diffusion of innovations framework to address the research objectives. Of the reviewed literature, we found relative advantage and compatibility were two dominant attributes to strengthen the adoption of PA, and the complexity attribute was rarely used to promote the adoption of PA. This study shows that change agents do not fully use five attributes of innovation when they promote PA technology to stakeholders to adopt. Thus, we recommend studies from the agricultural extension specialists’ perspectives in the future may determine contributions to motivate farmers’ adoption of PA, in particular related to complexity.
Spatial and Temporal Spread of the Coronavirus Pandemic using Self Organizing Neural Networks and a Fuzzy Fractal Approach
Authors: Melin Patricia , Castillo Oscar
Published: June 2021

In this article, the evolution in space and in time of the coronavirus pandemic is studied by utilizing a neural network with a self-organizing nature for the spatial analysis of data, and a fuzzy fractal method for capturing the temporal trends of the time series of the countries. Self-organizing neural networks possess the capability for clustering countries in the space domain based on their similar characteristics with respect to their coronavirus cases. In this form enabling finding the countries that are having similar behavior and thus can benefit from utilizing the same methods in fighting the virus propagation. To validate the approach, publicly available datasets of coronavirus cases worldwide have been used. In addition, a fuzzy fractal approach is utilized for the temporal analysis of time series of the countries. Then, a hybrid combination of both the self-organizing maps and the fuzzy fractal approach is proposed for efficient COVID-19 forecasting of the countries. Relevant conclusions have emerged from this study, that may be of great help in putting forward the best possible strategies in fighting the virus pandemic. A lot of the existing works concerned with the Coronavirus have look at the problem mostly from the temporal viewpoint that is of course relevant, but we strongly believe that the combination of both aspects of the problem is relevant to improve the forecasting ability. The most relevant contribution of this article is the proposal of combining neural networks with a self-organizing nature for clustering countries with high similarity and the fuzzy fractal approach for being able to forecast the times series and help in planning control actions for the Coronavirus pandemic.
Using Microcomputers in an Online Introduction to Horticulture Class
Authors: Burnett Stephanie Elaine
Published: June 2021

Online courses in horticulture increase the breadth of students who may be able to enroll. However, it is challenging to create hands-on learning experiences in online classes that are valuable for student learning. In an online introduction to horticulture class at the University of Maine, we created a hands-on project that is appropriate for students to work on independently at home. Students built an environmental monitoring system using a relatively inexpensive Raspberry Pi microcomputer and sensors for monitoring environmental factors that impact plant growth with a particular focus on monitoring temperature and humidity. They monitored the growing environment in their homes while growing house plants and used the information from their environmental monitoring system to determine whether their home environment was suitable for growing plants. Students were asked to use a pre-existing computer program in the Python language to monitor the environment. They also learned about how components of the code function and changed some simple parts of the code. A majority of students working on this project felt moderately confident, somewhat more confident, or very confident about their ability to use a Raspberry Pi microcomputer in the future. This project provides students with valuable hands-on experience in building environmental monitoring systems and provides them with a deeper understanding of the impact of the environment on plant growth.
Fast Learning in Complex Domains
Authors: Worden Robert
Published: June 2021

Bayesian formulations of learning imply that whenever the evidence for a correlation between events in an animal’s habitat is sufficient, the correlation is learned. This implies that regularities can be learnt rapidly, from small numbers of learning examples. This speed of learning gives maximum possible fitness, and no faster learning is possible. There is evidence in many domains that animals and people can learn at nearly Bayesian optimal speeds. These domains include associative conditioning, and the more complex domains of navigation and language. There are computational models of learning which learn at near-Bayesian speeds in complex domains, and which can scale well – to learn thousands of pieces of knowledge (i.e., relations and associations). These are not neural net models. They can be defined in computational terms, as algorithms and data structures at David Marr’s [1] Level Two. Their key data structures are composite feature structures, which are graphs of multiple linked nodes. This leads to the hypothesis that animal learning results not from deep neural nets (which typically require thousands of training exam-ples), but from neural implementations of the Level Two models of fast learning; and that neu-rons provide the facilities needed to implement those models at Marr’s Level Three. The required facilities include feature structures, dynamic binding, one-shot memory for many feature struc-tures, pattern-based associative retrieval, unification and generalization of feature structures. These may be supported by multiplexing of data and metadata in the same neural fibres.
On the Use of Electrical Resistivity Method in Mapping Potential Sources and Extent of Pollution of Groundwater Systems in Lapai Town, Niger State, Nigeria.
Authors: Tsepav Matthew Tersoo , Badeggi Aliyu Yahaya , George Obaje Nuhu , Tanko Usman Yusuf , Ibbi Ibrahim Samuel
Published: June 2021

Electrical resistivity method employing the Schlumberger array was used to occupy forty four (44) vertical electrical sounding points in Lapai town with the aim of determining the depth to aquifers, aquifer thicknesses and aquifer protective capacity. The G41 Geotron resistivity meter was used in obtaining the apparent resistivity data which was processed using Interpex 1XD resistivity interpretation software. The results revealed four lithologic sections which include top lateritic soil, sandy clay, fractured basement and fresh basement. Both confined and unconfined aquifers were identified within the area, with four classes of aquifer proactive capacities as high, moderate, weak and poor. While the aquifer at VES 20 was highly protected, twenty other aquifers were moderately protected, eight others had weak protection and fifteen aquifers were poorly protected. The aquifers were generally of good thicknesses and at varying reasonable depths, making them good reservoirs of water in appreciable quantity. The average aquifer thickness was estimated to be 48.36m while the average depth to aquifers was estimated to be 56.68m.
A Decomposed Fracture Network Model for Characterizing Well Performance of Fracture Networks on the Basis of an Approximated Flow Equation
Authors: Liu Jiazheng , Liu Xiaotong , Zhu Hongzhang , Ma Xiaofei , Zhang Yuxue , Zeng Jingying , Luo Wanjing , Teng Bailu , Li Yang , Nie Wan
Published: June 2021

The gridless analytical and semianalytical methodologies can provide credible solutions for describing the well performance of the fracture networks in a homogeneous reservoir. Reservoir heterogeneity, however, is common in unconventional reservoirs, and the productivity can vary significantly along the horizontal wells drilled for producing such reservoirs. It is oversimplified to treat the entire reservoir matrix as homogeneous if there are regions with extremely nonuniform properties in the reservoir. However, the existing analytical and semianalytical methods can only model simple cases involving matrix heterogeneity, such as composite, layered, or compartmentalized reservoirs. A semianalytical methodology, which can model fracture networks in heterogeneous reservoirs, is still absent; in this study, we propose a decomposed fracture network model to fill this gap. We discretize a fractured reservoir into matrix blocks that are bounded by the fractures and/or the reservoir boundary and upscale the local properties to these blocks; therefore, a heterogeneous reservoir can be represented with these blocks that have nonuniform properties. To obtain a general flow equation to characterize the transient flow in the blocks that may exhibit different geometries, we approximate the contours of pressure with the contours of the depth of investigation (DOI) in each block. Additionally, the borders of each matrix block represent the fractures in the reservoir; thus, we can characterize the configurations of complex fracture networks by assembling all the borders of the matrix blocks. This proposed model is validated against a commercial software (Eclipse) on a multistage hydraulic fracture model and a fracture network model; both a homogeneous case and a heterogeneous case are examined in each of these two models. For the heterogeneous case, we assign different permeabilities to the matrix blocks in an attempt to characterize the reservoir heterogeneity. The calculation results demonstrate that our new model can accurately simulate the well performance even when there is a high degree of permeability heterogeneity in the reservoir. Besides, if there are high-permeability regions existing in the fractured reservoir, a BDF may be observed in the early production period, and formation linear flow may be indistinguishable in the early production period because of the influence of reservoir heterogeneity.
Cartografia escolar e jogos eletrônicos
Authors: Rizzatti Maurício , Becker Elsbeth Léia Spode , Cassol Roberto
Published: June 2021

Os mapas se fazem presentes em inúmeros jogos eletrônicos e os jogadores, que conseguem interpretá-los, possuem uma grande vantagem sobre os adversários. A Cartografia Escolar fornece subsídios para atividades de leitura e interpretação de documentos cartográficos na Educação Básica, com noções dos tipos de visão, alfabeto cartográfico, estruturação da legenda, escala e proporção. Com base nisso, esse trabalho tem por objetivo os mapas disponíveis no jogo Call of Duty: Warzone e demonstrar a importância de desenvolver um aluno alfabetizado cartograficamente para  conseguir interpretá-los de forma que o auxilie na tomada de decisões de acordo com seu estilo de jogo. No mencionado game, o nível de informação do mapa varia de acordo com a escala de visualização. Assim, em uma escala menor, os pontos são representações simbólicas, com grande nível de abstração, visto que círculos e quadrados correspondem a estações de compra e veículos, respectivamente. O jogador, ao aplicar zoom na visualização, tem o mapa com uma escala cartográfica maior, fato que promove um nível de detalhamento, conseguindo visualizar os tipos de veículos com uma representação icônica. Assim, para a interpretação do mapa, o jogador deve recorrer a legenda, identificando a variação dos signos em decorrência da escala de visualização da representação cartográfica. Os professores podem utilizar esse recurso para instigar seus alunos, fazendo uso de mapas de jogos digitais em aula, fato que pode promover a atenção, sobretudo dos alunos gamers, despertando sua curiosidade com um tema discutido nas aulas de Geografia.
Expanding the Envelope of Fiber-Optic Sensing for Reservoir Description and Dynamics
Authors: Al-Qasim Abdulaziz , Alabduh Sharidah , Alabdullateef Muhannad , Alsubhi Mutaz
Published: June 2021

Fiber-optic sensing (FOS) technology is gradually becoming a pervasive tool in the monitoring and surveillance toolkit for reservoir engineers. Traditionally, sensing with fiber optic technology in the form of distributed temperature sensing (DTS) or distributed acoustic sensing (DAS), and most recently distributed strain sensing (DSS), distributed flow sensing (DFS) and distributed pressure sensing (DPS) were done with the fiber being permanently clamped either behind the casing or production tubing. Distributed chemical sensing (DCS) is still in the development phase. The emergence of the composite carbon-rod (CCR) system that can be easily deployed in and out of a well, similar to wireline logging, has opened up a vista of possibilities to obtain many FOS measurements in any well without prior fiber-optic installation.

Currently, combinations of distributed FOS data are being used for injection management, well integrity monitoring, well stimulation and production performance optimization, thermal recovery management, etc. Is it possible to integrate many of the distributed FOS measurements in the CCR or a hybrid combination with wireline to obtain multiple measurements with one FOS cable? Each one of FOS has its own use to get certain data, or combination of FOS can be used to make a further interpretation.

This paper reviews the state of the art of the FOS technology and the gamut of current different applications of FOS data in the oil and gas (upstream) industry. We present some results of traditional FOS measurements for well integrity monitoring, assessing production and injection flow profile, cross flow behind casing, etc.

We propose some nontraditional applications of the technology and suggest a few ways through. Which the technology can be deployed for obtaining some key reservoir description and dynamics data for reservoir performance optimization.
Sand Handling Solutions Through the Use of Low Geometric Index Progressing Cavity Pumps, La Hocha Field, Colombia
Authors: Martinez Lozano Jorge Alberto , Cruz Torres Ediberto , Hernandez Castro Nadia Maoly , Coronel Avila Jorge Alberto , Soltys Tim , Ariza Gonzalez Gustavo Andres
Published: June 2021

A solution for extend run life with no intervention in a high sand cut and high viscous fluid application for La Hocha field (Huila, Colombia) is presented through the installation of Progressing Cavity Pumps (PCP) designed with aggressive geometries including low rotor swept angle and minimum geometry index concepts. This application has 100-300 BFPD flow rate, sand cut up to 40%, 16°API fluid and 850 cp @ 100°F.

This document shows the methodology applied in the selection of well candidates with high frequency of interventions due pump failures associated to sand production and well sanded. The effect of the PCP geometry design, cross sectional area, pitch length, helix angle, pump fit, and elastomer were evaluated consistently as selection criteria in order to verify their impact on PCP run life for sand production applications. The document aims to validate the PCP theoretical design principles with the statistic and results gathered from field during the past 3 years in La Hocha field application.

The "Fat Boy project" resulted in less intervention, well services, minimizing production delays and associated costs. The project started on mid-2012, due to successful results has been expanded and nowadays represents the 85 percent of the wells in La Hocha field. This is all part of a combined effort looking for reliable and cost-effective solutions for challenging applications. Progressing Cavity Pumps are used in a variety of oil and gas applications where their beneficial characteristics such as positive displacement, high efficiency, low internal shear rates and pulseless flow provide advantages over other artificial lift systems. PC pumps are available in several geometries which determine their suitability for specific applications assuring optimal performance and extended run life.
Analysis of Nitrogen Minimum Miscibility Pressure MMP and Its Impact on Instability of Asphaltene Aggregates - An Experimental Study
Authors: Elturki Mukhtar , Imqam Abdulmohsin
Published: June 2021

Minimum miscibility pressure (MMP) is a critical parameter when undergoing miscible gas injection operations for enhanced oil recovery (EOR). Miscibility has become a major term in designing the gas injection process. When the miscible gas contacts the reservoir oil, it causes changes in the basic oil properties, affecting reservoir oil composition and equilibrium conditions. Changes in conditions may also favor flocculation and deposition of organic solids, mainly asphaltene, which were previously in thermodynamic equilibrium. The main purpose of this study is to investigate how the most important parameters, such as oil temperature and oil viscosity, could affect the nitrogen (N2) MMP and the instability of asphaltene aggregation. Three sets of experiments were conducted: first, the determination of MMP was performed using a slim-tube packed with sand. The impact of crude oil viscosity using 32, 19, and 5.7 cp; and temperature using 32, 45, and 70 °C, were investigated. The results showed that the N2 MMP decreased when crude oil temperature increased. The temperature is inversely proportional to the N2 MMP due to the N2 remaining in a gaseous phase at the same conditions. In terms of viscosity, the MMP for N2 was found to decrease with the reduction in oil viscosity. Second, the effect of miscibility N2 injection pressure on asphaltene aggregation using 750 psi (below miscible pressure) and 1500 psi (at miscible pressure) was investigated using a specially designed filtration vessel. Various filter membrane pores sizes were placed inside the vessel to highlight the effect of asphaltene molecules on plugging the unconventional pore structure. The results demonstrated that increasing the pressure increased asphaltene weight percentage. The asphaltene weight percent was higher when using miscible injection pressure compared to immiscible injection pressure. Also, the asphaltene weight percentage increased when the pore size structure decreased. Finally, the visualization of asphaltene deposition over time was conducted, and the results showed that asphaltene particles started to precipitate after 2 hours. After 12 hours, the colloidal asphaltenes were fully precipitated.
An Enhanced Approach to the Remediation of Scale Induced Formation Damage - Offshore Trinidad
Authors: Francis-LaCroix Kyethann , King Joel , Moonilal Laura , Rauceo Reon
Published: June 2021

The remediation of flow assurance challenges in field's offshore Trinidad is a foci of oil and gas operators in Trinidad West Indies. These challenges are heightened by field maturity and the corresponding increase in water production. With this increased water influx, production chemistry and specific flow assurance challenges also arise. One of the primary challenges include the precipitation and deposition of inorganic mineral scales. Coupled with this, mineralogy data and core data studies indicated that the sands of some of the producing fields offshore Trinidad are highly susceptible to scale precipitation in the formation water (Holder, 1990). As such, measures are often implemented to assure the successful and economical flow of hydrocarbon stream from the reservoir to the point of sale.

In this geographical area, stimulation acid treatments were typically deployed for remediation of formation damage of which scale precipitation was a main type. However, based on the previous production histories, the production gains following these acid treatments were short-lived. In addition, the accompanying financial loss is often compounded by other flow assurance challenges that were precursed by scale deposition.

This paper will discuss the use of inhibitory squeeze application techniques as a preventative approach to formation damage resulting from scale precipitation. This application is the first of its kind performed in the Teak field. Thus, results obtained will highlight further opportunity to successfully stimulate other fields in this region prone to scale deposition. The results obtained from this application will be represented in the form of a comparative analysis. The production indices attained via the conventional means of scale remediation, will be compared with that achieved via the strategic placement of phosphonate-based chemistries. Additionally, methods employed to avert the challenges of squeeze treatments in offshore environments will also be discussed as well as lessons learned from this approach.
Unlocking Idle Production in an Offshore Sandstone Oil Field With Gas Hydrate Issues
Authors: Daramola Babalola
Published: June 2021

This publication presents how an oil asset unlocked idle production after numerous production upsets and a gas hydrate blockage. It also uses economics to justify facilities enhancement projects for flow assurance. Field F is an offshore oil field with eight subsea wells tied back to a third party FPSO vessel.

Field F was shut down for turnaround maintenance in 2015. After the field was brought back online, one of the production wells (F5) failed to flow. An evaluation of the reservoir, well, and facilities data suggested that there was a gas hydrate blockage in the subsea pipeline between the well head and the FPSO vessel. A subsea intervention vessel was then hired to execute a pipeline clean-out operation, which removed the gas hydrate, and restored F5 well oil production. To minimise oil production losses due to flow assurance issues, the asset team evaluated the viability of installing a test pipeline and a second methanol umbilical as facilities enhancement projects.

The pipeline clean-out operation delivered 5400 barrels of oil per day production to the asset. The feasibility study suggested that installing a second methanol umbilical and a test pipeline are economically attractive. It is recommended that the new methanol umbilical is installed to guarantee oil flow from F5 and future infill production wells. The test pipeline can be used to clean up new wells, to induce low pressure wells, and for well testing, well sampling, water salinity evaluation, tracer evaluation, and production optimisation.

This paper presents production upset diagnosis and remediation steps actioned in a producing oil field, and aids the justification of methanol umbilical capacity upgrade and test pipeline installations as facilities enhancement projects. It also indicates that gas hydrate blockage can be prevented by providing adequate methanol umbilical capacity for timely dosing of oil production wells.
Rate Transient Analysis in Two-Layered Reservoir Without Crossflow
Authors: Vasquez Michael B. , Adrian Pedro M.
Published: June 2021

Analysis of modern production data also known as Rate Transient Analysis (RTA) is a technique to perform reservoir characterization using the combination of bottomhole flowing pressure and flow rate data without the need to close wells. These methods allow the estimation of the Hydrocarbon Initially In-Place (HIIP), production forecast and main reservoir parameters.

Several RTA methods have already been developed to analyze different reservoir models such as homogeneous, naturally fractured, geopressurized, hydraulically fractured, however, in the case of layered reservoirs the studies are almost null although there are several studies conducted in the area of pressure transient analysis.

This paper presents the analytical derivation of the Palacio-Blasingame type curves to analyze production data of a two-layered reservoir model without crossflow or hydraulic communication between them.

A new set of type curves were generated by applying the Gaver Stehfest algorithm with Matlab to achieve the solution of the inverse of the Laplace space considering a constant flow of production flow and a flow regime in the radial pseudosteady-state, then applying the definitions dimensionless the proposed method was derived.

Synthetic data were generated with a commercial simulator to validate the method. Furthermore this paper presents a field case study application. The results were compared to the type curve for homogenous reservoirs, volumetric method as well as well testing results.

Results confirmed the applicability of rate transient analysis technique in a two-layered reservoir without crossflow with a single drainage area and the same initial pressure for all layers (same pressure gradient of formation), and different values of thickness of the layers, permeability and porosity.
Simulating Downhole Temperature Logging Data for Optimum Downhole Production Surveillance
Authors: Hashmi Gibran M. , Hamza Farrukh , Azari Mehdi
Published: June 2021

Reservoir management best practices originate from efficient well operations. The fluid flow profile from individual wells can change over time, sometimes unpredictably; as the reservoirs become depleted, changes in hydrocarbon properties occur, and water cut begins to increase. During primary, secondary, and tertiary recovery from conventional and unconventional wells, production surveillance is pivotal for optimum reservoir management. Determining the downhole production flow profile from multiple zones helps to manage drawdown pressure, regulate surface choke settings, and mitigate excessive water production.

This paper presents a rigorous mechanistic analysis of the heat transfer and fluid flow around the wellbore to aid in determining a generalized wellbore flow profile. The approach enables the calculation of multiphase rates independently of downhole spinner data and is based almost solely on temperature measurements. Because temperature measurements are reliable and more commonly available, the method provides a robust technique to determine flow contributions across a broad spectrum of surveillance applications. The technique is shown to work with other logs, such as capacitance, fluid density, and gas holdup tool, to relay more refined information about fluid phases during production.

The methodology presents an application of transient-temperature modeling for computing flow rates from temperature data obtained during a wireline run. The approach includes an analytical wellbore fluid transient-temperature model. Temperature calculations depend on mass flow rate and flow duration; therefore, an inversion technique is applied to match the measured temperature and calculated temperature for a given time duration to estimate flow rate. The model is observed to depend on determining an accurate geothermal gradient, particularly in cases of early time flow. The various heat transfer resistances in the system are calculated based on the completion mechanics. The method also accounts for the effect of friction and pressure drop in the wellbore on fluid temperature. The case study included demonstrates the utility and value of the transient model. The transient nature of the model also facilitates multiple applications. Real-time flow rate monitoring, zonal contributions, flow behind casing, quantitative determination of leaks, and completion integrity are all potential applications of the proposed method.

The transient-temperature modeling methodology can be used with production logging spinners to calibrate the model and provide a permanent downhole monitoring tool to help avoid costly logging reruns. The study provides a foundation for various applications arising from conventional production logging measurements and could be particularly useful in cases, such as offshore fields, where more evolved unconventional techniques can be difficult and costly to apply.
Proposal EOR Fiscal Incentives to Increase the Recovery Factor in Mexican Fields Implementing Enhanced Oil Recovery Methods through Sensitivity Analysis with Different Contracts
Authors: Espinola Oswaldo , Nunez Fernando , Malibran Pedro Tomas
Published: June 2021

The current business strategy of Operators in Mexico has considered finance Enhance Oil Recovery projects. Moreover, the potential in Mexico for EOR is represented by 80% of the total production coming from mature fields. However, these projects are difficult to be executed below current circumstances, oil prices and existing fiscal terms. For this reason, there is an opportunity to evaluate how to switch the situation and generate scenarios where it might be possible to perform such as complex project.

Therefore, this study presents a methodology from a technical and economical perspective that includes the selection of a representative reservoir, evaluating different production forecast scenarios below EOR schemes, comparing fiscal models and running sensitivity analysis to end up with an incentive adjustment, to evaluate the potential benefits of fiscal incentives and how they could be applied effectively to EOR implementation projects.

To demonstrate the potential of these projects in Mexico, a reservoir with specific characteristics had been selected to simulate the performance of a mature field where thermal pilot projects are conceptualized. Nevertheless, the focus of this study is to evaluate the current fiscal terms and taxes versus innovative fiscal terms with applied incentives.

This work pursuits to find a window of opportunity for complex projects that embraces current oil prices, appropriate fiscal terms, tax incentives, and technical considerations. Overall, the proposed methodology defines how to apply the appropriate incentive in combination with several parameter to enable the execution of these projects.

Finally, as a result of this study, it had been demonstrated that at given conditions and adding a package of incentives, there is a win-win schema where the Government and the Operators obtain higher returns than the conditions of exploiting the fields only with natural depletion. These proposed conditions can be used to promote economic benefits that encourage EOR projects and attract investment in Mexico, and consequently, increase recovery factor of mature fields.
Digital Workflow to Enhance Reservoir Management Strategies for A Complex Oil Field Through Real Time and Advanced Engineering Monitoring Solution
Authors: Alvarez Julieta , Espinola Oswaldo , Diaz Luis Rodrigo , Cruces Lilith
Published: June 2021

Increase recovery from mature oil reservoirs requires the definition of enhanced reservoir management strategies, involving the implementation of advanced methodologies and technologies in the field's operation.

This paper presents a digital workflow enabling the integration of commonly isolated elements such as: gauges, flowmeters, inflow control devices; analysis methods and data, used to improve scientific understanding of subsurface flow dynamics and determine improved operational decisions that support field's reservoir management strategy. It also supports evaluation of reservoir extent, hydraulic communication, artificial lift impact in the near-wellbore zone and reservoir response to injected fluids and coning phenomenon. This latest is used as an example to demonstrate the applicability of this workflow to improve and support operational decisions, minimizing water and gas production due to coning, that usually results in increasing production operation costs and it has a direct impact decreasing reservoir energy in mature saturated oil reservoirs.

This innovative workflow consists on the continuous interpretation of data from downhole gauges, referred in this paper as data-driven; as well as analytical and numerical simulation methodologies using real-time raw data as an input, referred in this paper as model-driven, not commonly used to analyze near wellbore subsurface phenomena like coning and its impact in surface operation. The resulting analyses are displayed through an extensive visualization tool that provides instant insight to reservoir characterization and productivity groups, improving well and reservoir performance prediction capabilities for complex reservoirs such as mature saturated reservoirs with an associated aquifer, where undesired water and gas production is a continuous challenge that incorporates unexpected operational expenses.
Artificial Intelligence AI / Machine Learning ML Drives Increased Capital Efficiency and Minimizes Geological Risk in E&P Operations
Authors: Aming Anthony
Published: June 2021

This paper presents how Artificial Intelligence (AI) / Machine Learning (ML) technology uses unsupervised genetics algorithms in Exploration, Drilling Operations, Field Appraisal, Development and multiple 3D seismic volumes comparisons to minimize geological risk and uncertainty resulting in increased capital efficiency. We will present a high level overview of why this technology was invented and how it works. We will show you how you can use it to significantly reduce the time to achieve your organizational goals while reducing geotechnical risk and uncertainty and optimize the cycle time from Lead to Production. Outputs include a comprehensive analysis of your entire 3D Seismic Data Volume to identify and high grade, quality leads and prospects with high resource potential in the near, medium and long term. This approach will allow an evaluation of the field geological risk (reservoir distribution, trap, seal, source, hydrocarbon migration pathway from source into reservoir) and initial possible hydrocarbon content/type evaluation (e.g. DHI evaluation) without disrupting your current workflow. The results will quickly delineate possible structural and stratigraphic targets. This will also provide the Production Asset with additional support in their appraisal and development drilling programmes. Optimally place horizontal wells and injectors / offtakes in Improved Oil Recovery/Enhanced Oil Recovery (IOR / EOR) projects in areas of the field having the highest reservoir continuity to optimize the cycle time from concept to production. The case studies and examples presented will demonstrate how the technology and approach serve to increase the probability of success leading to increased capital efficiency and profitability.
A Simulation Study of the Effect of Injecting Carbon Dioxide with Nitrogen or Lean Gas on the Minimum Miscibility Pressure
Authors: Mansour Ahmed GH , Gamadi Talal , Saoyleh Hussain R
Published: June 2021

The objective of this study is to determine the effects of the concentration of injected gases on recovery factors. CO2 has been used for flooding because it requires low injection pressures to achieve miscibility. However, the availability of CO2 is an issue. CO2 required for the process is not sufficient for the reservoir under consideration. Moreover, its benefit-cost ratio (b/c) represents another issue; higher volumes of CO2 increases the economic expenditures. An alternative is to inject lean gas or nitrogen along with CO2 to achieve better recoveries at optimum costs and suitable pressure.

Slim tube simulation using a commercial simulator is utilized to measure the minimum miscibility pressure (MMP) of an injected gas mixture. The mixture contains CO2/N2 or CO2/lean gas. Using different concentrations in the injected mixture, an effect on the recovery factor is studied. The first 30 runs have 100% concentration of each individual gases i.e. N2, CO2 and lean gas. Based on these runs, the simulation model is validated using the co-relations present in the literature. Gas mixtures of CO2/N2 and CO2/lean gas were then simulated using the compositional model to test the effect on MMP by varying the concentration of each gas in the mixture. By changing the volumes of the gas in the injected mixture, we can find the optimum concentration of each component in the mixture in terms of MMP.

From the results obtained through simulation, it can be deduced that higher percentages of CO2 in the mixture would result in reduced minimum miscibility pressure. The addition of a secondary slug to the injected CO2 fluid increases the pressure required to achieve miscibility. Of N2 and Lean gas, Lean gas provided better results as it showed low miscibility pressure responses compared to the same amount of N2 gas. For example, for a case, 50% CO2 and 50 %N2 or lean gas mixture, the MMP for the lean gas mixture is 3500 Psi, while for N2 mixture it was 4667 Psi. However, lean gas is expensive as compared to N2 and N2 is easily available. N2, if used in optimum concentration along with CO2 can produce greater recoveries keeping the process cost-effective while satisfying other constraints. CO2 is widely used for miscible injection, but it presents problems like costs, corrosion, and asphaltene deposition etc. The study can give an idea of the success of carrying out EOR through gas flooding by using N2 and CO2 to enhance recovery at low cost. N2 is easily available from air and it is cheap.
20 Years of Independent Oil and Gas Audits: The Trinidad and Tobago Story
Authors: Welsh Christian Paul
Published: June 2021

Over the 20 year period from 2001 to 2020, the Ministry of Energy and Energy Industries (MEEI) of Trinidad and Tobago commissioned 19 gas and 3 oil audits conducted by independent consultants. Trinidad and Tobago's natural gas Technically Recoverable Resources (TRR) moved from a P1+C1 TRR to Production Ratio of greater than 30 in 2001 to less than 10 years as production has grown from a low of 1.5 Bcf/d to a high of 4.3 Bcf/d. Despite this, the opening of a new exploration basin in the Deepwater has resulted in greater than 100% technically recoverable resource replacement in the last three years for natural gas and a 770% increase in Prospective Resources for crude oil. The data from these successful audits have served to demonstrate the astute management by the Government and People of Trinidad and Tobago of the country's hydrocarbon resources.
Effects of Small-Dose S-Ketamine On Anesthesia-Induced Atelectasis In Patients Undergoing General Anesthesia Accessed By Lung Ultrasound: Study Protocol For A Randomized, Double-Blinded Controlled Trial
Authors: Zhang Di , Liang Yi , Bao Di , Xiong Wei , Li Lu , Wang Yaxin , Liu Bin , Jin Xu
Published: June 2021

Background: Aelectasis after anesthesia induction in most patients undergoing general anesthesia may lead to postoperative pulmonary complications (PPCs) and affect postoperative outcomes. However, there is still no existing effective method used for the prevention of perioperative atelectasis. S-ketamine may prevent atelectasis due to airway smooth muscle relaxation and anti-inflammatory effects. Lung ultrasound is a portable and reliable bedside imaging technology for diagnosing anesthesia-induced atelectasis. In this study, we aim to assess whether a small dose of S-ketamine can reduce the incidence of atelectasis after intubation under general anesthesia using lung ultrasound, in order to prevent the early formation of perioperative atelectasis and PPCs.Methods: This is a single-institution, prospective, randomized controlled, parallel grouping, and double-blind study. From October 2020 to March 2022, 100 patients (18-60 years old) scheduled for elective surgery will be recruited from Beijing Tiantan Hospital, Capital Medical University, and randomly assigned to the S-ketamine group (Group S) and the normal saline group (Group N) at a ratio of 1:1. The label-masked agents will be administered 5 min before induction, and all patients will undergo a standardized general anesthesia protocol. Related data will be collected at three-time points: after radial artery puncture (T1), 15 min after tracheal intubation (T2), and before extubation (T3). The primary outcome will be the total lung ultrasound scores (LUS) at T2. Secondary outcomes will include LUS in six chest regions at T2, total LUS at T3, arterial blood-gas analysis results (PaCO2, PaO2) and PaO2/FiO2 at T2 and T3, plateau pressure(Pplat) and dynamic lung compliance (Cdyn) at T2 and T3. The incidence of postoperative complications associated with S-ketamine and PPCs at 2 h and 24 h after surgery will be recorded.Discussion: This trial aims to explore whether a simple and feasible application of S-ketamine before the induction of general anesthesia can prevent atelectasis. The results of this study may provide new ideas and direct clinical evidence for the prevention and treatment of perioperative pulmonary complications during anesthesia.Trial registration: ClinicalTrials.gov identifier: NCT04745286.
A Lived Experience Co-Designed Study Protocol for a Randomised Control Trial: The Attempted Suicide Short Intervention Program (ASSIP) or Brief Cognitive Behavioural Therapy as Additional Interventions After a Suicide Attempt Compared to a Standard Suicide Prevention Pathway (SPP).
Authors: Stapelberg Nicolas JC , Bowman Candice , Woerwag-Mehta Sabine , Walker Sarah , Davis Angela , Hughes Ian , Michel Konrad , Pisani Anthony R , Engelen Heidy Van , Delos Mia , Hageman Tamara , Fullerton-Smith Kim , Krishnaiah Ravikumar , McDowell Sarah , Cameron Alison , Scales Trudy-Lee , Dillon Cherie , Gigante Titta , Heddle Cindy , Mudge Natalie , Zappa Anne , Edwards Michelle , Gutjahr Sigrun , Joshi Hitesh , Turner Kathyrn
Published: June 2021

Background

Despite being preventable, suicide is a leading cause of death and a major global public health problem. For every death by suicide, many more suicide attempts are undertaken, and this presents as a critical risk factor for suicide. Currently there are limited treatment options with limited underpinning research for those who present to Emergency Departments with suicidal behaviour. The aim of this study is to assess if adding one of two structured suicide specific psychological interventions (Attempted Suicide Short Intervention Program [ASSIP] or Brief Cognitive Behavioural Therapy [CBT] for Suicide Prevention) to a standardised clinical care approach (Suicide Prevention Pathway [SPP]) improves outcomes for consumers presenting to a Mental Health Service with a suicide attempt.
Methods

This is a randomised controlled trial with blinding of those assessing the outcomes. People who attempt suicide or experience suicidality after a suicide attempt, present to the Gold Coast Mental Health and Specialist Services, are placed on the Suicide Prevention Pathway (SPP) and meet the eligibility criteria, are offered the opportunity to participate. A total of 411 participants will be recruited for the study, with 137 allocated to each cohort (participants are randomised to SPP, ASSIP + SPP, or CBT + SPP). The primary outcomes of this study are re-presentation to hospital with suicide attempt and/or suicidal ideations. Death by suicide rates will also be examined. Self-reported level of suicidality, depression, anxiety, stress, resilience, problem-solving skills, self- and therapist-reported level of therapeutic engagement are also being examined. Psychometric data are collected at baseline, end of interventions, 6,12, and 24 months.
Discussion

This project will move both ASSIP and Brief CBT from efficacy to effectiveness research, with clear aims of assessing the addition of two structured psychological interventions to treatment as usual, providing a cost-benefit analysis of the interventions, thus delivering outcomes providing a clear pathway for rapid translation of successful interventions.
Trials registration

: NCT04072666 - Registered on 28th August 2019 on Clinical Trials US Gov (https://www.clinicaltrials.gov/ct2/show/NCT04072666?term=NCT04072666&draw=2&rank=1) and ANZCTR (https://www.anzctr.org.au/TrialSearch.aspx)
The Investigations of Atrial Fibrillation Burden after Cryoballoon Ablation Detected by Insertable Cardiac Monitor in Patients with Paroxysmal Atrial Fibrillation: A Study Protocol for a Multicenter Randomized Controlled Trial (Cryo-ICM AF study)
Authors: Luo Di , Liu Yanhong , zhang yue , Xu Gang , Liu Enzhao , Liu Tong , Li Guangping
Published: June 2021

Background: With the increasing number of aged population in China, the mortality and disability caused by atrial fibrillation (AF) and its complications lead to serious social burden and becoming more prominent. Due to the high false-negative rates of AF detected by routine ECG, the results on the recurrent rate and AF burden after cryoballoon ablation (CBA) in real world are inconsistent so far. Since the extension of monitoring time, the increased detection of AF in patients, insertable cardiac monitor (ICM) has its unique merits. Methods: Cryo-ICM AF study is a prospective, multicenter randomized controlled trial with 200 participants with paroxysmal atrial fibrillation from 4 centers. Monitoring AF load after CBA though two monitoring methods— ICM and 24 hours holter during the 1 years follow-up of the two groups. All data will be observed and recorded in baseline, 30th days and 3 th , 6 th , 9 th and 12 th months after CBA, which including incidence rates of postoperative complications and recurrence conditions, cardioelectrical indexes from 24-hours holter in all subjects and ICM in ICM group, UCG parameters about atrium/ventricular size and diastolic/systolic function, and biochemical indicators. Disucssion: This is the first study design to confirm the effectiveness of cryoballoon in real world, monitoring AF load with ICM in patients with paroxysmal AF after CBA.Trial registration: Chinese Clinical Trial Registry, No. ChiCTR1900026364. Registered 9 Oct 2019, http://www.chictr.org.cn/index.aspx
Impact of The Correlation Between Channel Input And Side Information On Physical Layer Security Performances of Wireless Wiretap Channel
Authors: Pakravan Saeid , Hodtani Ghosheh Abed
Published: June 2021

In this paper, a discrete memoryless wiretap channel with non-causal side information known at the encoder is considered. We (i) characterize capacity region for the Gaussian version of this channel by considering correlation between channel input and side information available at the transmitter; (ii) analyze the impact of correlation on the performance of physical layer security in a Rayleigh fading wiretap channel by deriving closed-form expressions on the average secrecy capacity (ASC) and secrecy outage probability (SOP). Further, to more show the impact of side information, asymptotic behavior of SOP is studied. Numerical evaluation of theoretical results is done finally.
Human muscle stem/progenitor cells are bi-potential adult stem cells
Authors: Shao Xiexiang , Fu Xin , Han Lili , Li Sheng , Wang Hongye , Zhou Shenao , Wang Jianhua , Hu Ping
Published: June 2021

Tendon injury occurs at high frequency and is difficult to repair. Identification human stem cells being able to regenerate tendon will greatly facilitate the development of regenerative medicine for tendon injury. We identified human muscle stem/progenitor cells having tendon differentiation potential both in vitro and in vivo. Interestingly, the tendon differentiation potential is not present in mouse muscle stem cells. These findings reveal that human muscle stem cells are bi-potential adult stem cells and can serve as a new source for tendon regeneration.