bluuebunny/crossref_metadata_2025 huggingface dataset:
O problema da verdade e a perspectiva jurídica: indicações teóricas para uma teoria da verdade jurídica
Authors: Barbosa Taveira Valéria Cristina , Marques de Oliveira Victor Hugo , Machado Flávia Palhares , Lemes de Oliveira Paulo César
Published: October 2020

: Este artigo tem como principal escopo a compreensão da verdade à luz da interdisciplinaridade da filosofia e do direito. Doravante, ambas as ciências se ocupam do tema para a resolução de seus próprios conflitos, conceitos e matérias afins. Não se pode deixar de negar que, para a teoria do conhecimento, a verdade está atrelada tanto a aspirações lógico-matemáticas quanto à possibilidade de se chegar ao verdadeiro pela experiência empírica. Este modo de compreender a verdade é explicado pela teoria da correspondência (também chamada de adequação ou conformidade). Todas as doutrinas que buscam respaldar a teoria do conhecimento não gozam de aplicabilidade na seara jurídica, isto ocorre porque o problema da verdade jurídica é justamente a sua sustentação em total desprezo pelas teorias filosóficas que embasam a verdade. É que, tratando-se de Poder Judiciário, não se pode tão somente almejar a verdade dos fatos, mas o modo como o legislador dispõe de comprovar a dinâmica dos acontecimentos em juízo, contrariando por completo a teoria do conhecimento. Esta investigação científica visa atenuar tais controvérsias tanto no âmbito da filosofia quanto do direito, além de propiciar meios de compreender a função desempenhada pela verdade nessas áreas do conhecimento humano.
Eficiência de protótipo de microambiente com controle sobre ventilação, temperatura e umidade, para roedores
Authors: Almeida Juliana Teixeira de , Schiaveto de Souza Albert , Conti Pereira Mauro , Gomes Matheus Bueno
Published: October 2020

O ambiente no qual o animal experimental se encontra deve ser padronizado, pois pode influenciar os resultados das pesquisas. A tecnologia existente, além de onerosa, não reúne em um único aparelho todas as especificações necessárias para esse fim. No intuito de controlar e padronizar, foi desenvolvido protótipo de microambiente utilizando o sistema Peltier, que é um método alternativo de refrigeração, com controle sobre temperatura, umidade, iluminação e ventilação, e testado em estudo experimental, comparando entre o grupo controle e experimental os parâmetros ambientais, consumo alimentar e hídrico e ganho ponderal. Eles foram analisados pelo teste t-Student, programa SigmaPlot, versão 12.5, significância de 5%. O protótipo despontou como produto diferenciado, superior ao comercializado, eficiente no controle das variáveis ambientais, mantendo sua estabilidade, bem como proporcionando atmosfera isolada e adequada para abrigar animais e mantê-los em ambiente controlado e passível de reprodução com custo reduzido, acessível a biotérios e grupos de pesquisa desprovidos de grandes verbas.
Análise do desempenho econômico da região Centro-Oeste, Brasil, de 2002 a 2015
Authors: Dorsa Antonio Carlos Cantero , Constantino Michel
Published: October 2020

O processo de desenvolvimento econômico proporciona externalidades de formas distintas, dependendo da composição produtiva de cada território; nesse contexto, as diferenças regionais podem resultar em maior ou menor crescimento econômico. O presente artigo investigou o desempenho da região Centro-Oeste entre 2002-2015 e o comparou com a média nacional, utilizando análise quantitativa. Os indicadores utilizados para a análise foram o PIB, Gini, Exportação, Importação e Grau de Abertura Comercial (GAC). Os resultados mostraram que, no Gini, os estados de Mato Grosso e Mato Grosso do Sul, MS, foram acima da média nacional, e Goiás, GO, abaixo. A variável PIB seguiu a média nacional, enquanto as exportações apresentaram nível acima da média, e, nas importações, apenas MS foi superior. O GAC de GO e MS foi acima da média nacional, e o de MT, abaixo. Conforme a literatura, a presente pesquisa confirma que o Centro-Oeste continua acima da média nacional.
Desafios no âmbito do planejamento e da difusão de iniciativas de turismo sustentável em uma Unidade de Conservação brasileira
Authors: Arruda Dyego de Oliveira , Oliveira Beatriz Boaretto , Mariani Milton Augusto Pasquotto , Silva Maurilio Barbosa de Oliveira da
Published: October 2020

O presente artigo tem como propósito analisar os desafios do planejamento e implantação de iniciativas de turismo sustentável em uma Unidade de Conservação (UC) brasileira: o Parque Natural Municipal do Açude da Concórdia (PaNaMAC). Foram conduzidas quatro entrevistas com atores institucionais da UC, ao passo que também se realizou a coleta de comentários publicados na página do TripAdvisor, na internet, por visitantes que estiveram no PaNaMAC. Os dados foram sistematizados com o uso do software Iramuteq e submetidos à análise de conteúdo. Percebeu-se que o PaNaMAC tem potencial para iniciativas de turismo sustentável, principalmente em função de seus ativos ambientais. Os turistas percebem o local como um atrativo em que é possível a prática de atividades conectadas com a perspectiva do turismo sustentável. Porém constatou-se que o poder público é um dos principais causadores dos empecilhos para a difusão do turismo sustentável no parque.
Design and Experiments of Voltage Sensor Based on Electric Field Coupling Principle and Differential Input Structure
Authors: Zhou Tonghao , Zhuang Zhe , Zhou Xiu , Wu Xutao , Li Xiuguang , Xiong Qing , Ji Shengchang
Published: October 2020

Traditional potential transformers have problems of large volume, difficulty in insulation, iron core saturation, ferroresonance overvoltage and poor transient response characteristics. The voltage sensor based on the principle of electric field coupling and differential input structure does not need to contact the measured object or ground, and can avoid the above problems. However, it requires a sufficiently high capacitance between the differential electrodes to obtain sufficient accuracy and a high voltage division ratio. The existing method of using mutual capacitance between the differential electrodes will cause many problems and fail to meet the practical needs. To solve the above problems, this paper innovatively uses multi-layer ceramic capacitor to replace the mutual capacitance and designs a new type of voltage sensor. In addition, by using single bypass small resistance grounding method to increase the input impedance of the differential signal processing circuit, error of the sensor is further reduced. The experimental results show that the sensor has excellent accuracy and great transient response characteristics. The ratio error under power frequency is within ±0.5% and the phase error is within 1. The ratio error in the range of 500 Hz∼30 kHz is within ±5% and the phase error is within 5. Moreover, it has the advantages of low cost, miniaturization, flexible shape and easy to adjust the voltage division ratio. These characteristics indicate that the sensor has good voltage measurement and sensor network potential.
Hüseyin Cahit Yalçın’ın Malta Hatıraları
Authors: GAZEL Ahmet
Published: October 2020

Mondros Mütarekesi’nden sonra Osmanlı Devleti’nde, İngilizlerin de baskısıyla ülkenin önde gelen kişileri tutuklanarak Bekirağa Bölüğü’ne hapsedilmiş ve daha sonra bunların bir kısmı Malta Adası’na sürülmüştür. Sürgüne giden bu kişiler arasında İttihat ve Terakki’nin önde gelen isimlerinden Hüseyin Cahit Yalçın da yer almıştır.
Malta’ya sürgüne gönderilerin bazıları gibi Hüseyin Cahit de sürgün hatıralarını kaleme almıştır. Hatta bu hatıralarını değişik tarihlerde olmak üzere üç defa yayımlamıştır. İlk olarak 1925 yılında Tanin’de yayımlamıştır. 1934-35 yıllarında Yedigün dergisinde tekrar yayımlamıştır. Son olarak ise 1955 yılında Halkçı gazetesinde yayımlamıştır. Hüseyin Cahit’in farklı tarihlerde tekrar yayımladığı Malta hatıraları hemen hemen aynı metne sahiptir. Ancak bazı olaylar hakkında birinde olmayan bir ayrıntıyı diğerinde verebilmektedir.
Bu çalışmada, özellikle Yedigün dergisinde yayımladığı metne dayalı olarak Hüseyin Cahit Yalçın’ın Malta hatıraları anlatılmıştır. Bunun yanında bildiri hazırlanırken Tanin ve Halkçı’daki metinler de kontrol edilerek tespit edilen farklı bilgiler de dikkate alınmıştır.
Intelligent Gas Lift Compressor Adjust Injection With Dynamic Conditions
Authors: Munding Paul , Hudson John , Karami Hamidreza
Published: October 2020

Approximately 40% of unconventional wells in the United States with artificial lift are using gas lift. One of the blessings of gas lift is that it is very forgiving and rarely fails. This has led some operators to the conclusion that gas lift doesn’t require a proper control and optimization scheme. The objective of this study is to use field data and show the importance and benefit of a controlled and optimized gas lift compressor to aid production.

The intelligent gas lift compressor utilizes a heavy computational process of taking a composite Vogel reservoir inflow model coupled with a Hagedorn & Brown outflow model that informs the Guo model to solve for a minimum critical rate to lift liquid droplets out of the wellbore. First, an empirical range of injection rates is used to find the rate with maximum unloading as indicated by a drop in casing injection pressure. Once this rate is found, reservoir inflow performance relationship (IPR) parameters are estimated to meet that condition. These parameters are held constant for a time period and injection rate needed is calculated based on production rate and pressure coming into the programmable logic controller (PLC) via digital connections. This approach is tested on a well and the production is monitored over a 3-month period. The collected data are used to analyze the benefits of an intelligent gas lift compressor control.

The data from a well with this intelligent gas lift system is monitored over a 3-month period. This includes a 20-day period of the compressor searching for an injection rate that shows to be the most efficient. Then the compressor control is set up with a critical rate control mode. This calculation is performed with an edge server that runs the intense calculations every minute to instruct the compressor what volume of injection it needs to achieve manipulation of an automated suction control valve and speed control of the engine driver. The surface casing pressure data shows a very stable unloading behavior profile, which is confirmed with very stable oil and gas production data over the observation period. An estimate of gained production during the periods of high line pressure along with stable unloading is given as the justification for outfitting the well site with the intelligent compressor controls. Despite gas lift’s importance as a lift technique, its control and optimization are still not properly addressed within the industry. This work’s proposed intelligent gas lift scheme can be a potentially valuable solution to unstable unloading of liquids, and benefit the operators significantly in production and revenues.
A New Way of Looking at Safety Culture Maturity Models-The Lens of Employee Engagement
Authors: Knode Thomas
Published: October 2020

Over the years, various authors have put forth cultural maturity models for organizations to describe the pathway towards high levels of safety performance. While these models are readily accepted and viewed as benchmarks for assessments of the state of safety culture, what lies beneath the premise, and what may we be searching for? We now know through both the study of organizations employee attitudes and brain science that individuals respond well to having a say in their work output and environment. If we apply the lens of employee engagement to a typical culture maturity model, it will look different. Ideally, every employee would feel empowered to identify hazards and be a party to the development of risk mitigation solutions. If we ask employees to participate on discreet occasions in observation programs, toolbox talks, and safety committees, does that guarantee full engagement? An employee who is fully engaged in safety is looking for it beyond those moments and may be better prepared to manage risk.

A new model looking at employee engagement and active participation in workplace safety would move along a continuum. Historically there has been a lack of regulatory guidance and legislative framework to support active participation, leaving individuals and organizations to make their judgments and actions. From there, governments implemented laws and regulations that formed the basis of expectations. Industry and companies then realized that management systems would help integrate the regulations with their specific processes to form a complementary set of requirements. We then understood that safety leadership from supervisors was needed to ensure workers understood and followed the process and adhered to the rules. Finally, we began asking the front line to participate, and ultimately own responsibility for looking out for themselves and each other. Each step must be built on the previous as it would be challenging to create a safety culture in the absence of external and internal requirements or safety leadership from supervisors. This continuum helps drive the maturity from the belief that "They own safety" to "We own safety" and encourage behavior beyond discreet point-in-time activities to a more complete and engaging program and workforce.

This different way of looking at cultural maturity through the lens of what should be expected of supervisors and employees may help organizations develop plans and strategies to achieve an incident and injury-free workplace.
Qualification and Deployment of Float Equipment as an Independent Mechanical Barrier in Unconventional Wells
Authors: Champeaux Christopher J. , Arrazola Alvaro J. , Patin Vincent , Stair Todd , Rogers Hank
Published: October 2020

The generally overlooked implications of intentional or unintentional overdisplacement of shoe track cement in production casings, resulting in what is commonly known as a wet shoe, are discussed in addition to how these implications/risks have been addressed and mitigated with recent developments in float equipment technology and operational methods. Additionally detailed are the operational, cost, and production efficiencies afforded by an engineered wet shoe system for primary cementing and completion operations.

To utilize an intentionally overdisplaced production casing shoe track, or wet shoe, a float valve was developed, tested, and manufactured with the intent to be used as an independent mechanical barrier, preventing inflow of hydrocarbon into the casing. This was accomplished by performing a float equipment qualification, meeting the requirements in API SPEC 10F (2018), and exceeding the requirements with additional testing comprised of static high-pressure and low-pressure testing with nitrogen to simulate formation gas pressure during cement phase change and before completion. Each discrete manufactured valve was also tested with low-pressure gas to validate each valve was fit for service before deployment. During a 20-well trial, a typical float check was used to test the barrier in place at the conclusion of cement displacement. Wellhead pressure was then monitored to confirm gas-tight integrity of the float equipment over time before completion operations.

New technology using float equipment, conventionally not regarded or considered for use as a mechanical barrier, was successfully developed and qualified for use as an independent mechanical barrier in uncemented shoe tracks and successfully deployed in low-permeability wells to maintain a two-barrier system without shoe track cement. This success was the culmination of the equipment design and qualification process with operational risk assessment/mitigation.
Identification of Fractures and Preferential Flow Paths Using Streamlines and Dynamic Data in Dual Porosity Dual Permeability Reservoir Models
Authors: Hongquan Chen , Changqing Yao , Akhil Datta-gupta , Ali A. Alturki , Majdi A Baddourah
Published: October 2020

Identification of the location and orientation of fractures and preferential flow paths using the dynamic reservoir response can provide insightful guidance for naturally fractured reservoir development and management. However, data assimilation for high-resolution fractured reservoir models using well responses is time consuming. The streamline-based technology has proven to be effective and efficient for subsurface flow modeling and inverse problems. We propose a novel and robust streamline tracing method in dual porosity dual permeability (DPDK) systems and an efficient workflow to identify fracture location in fractured reservoir models using dynamic data.

In DPDK models, the matrix-fracture interactions are typically described by non-neighbor connections (NNCs) which make streamline tracing non-trivial. We use a boundary layer method to reconstruct the fluxes and avoid flux discontinuities at NNCs. The flux reconstruction allows us to trace streamlines and compute the time of flight (TOF) in DPDK models. The fracture identification workflow relies on the streamline-based analytic sensitivity computation and rapid model calibration using dynamic data. Multiple realizations of fracture distribution are initialized and calibrated using observed well responses, for example water cut and BHP. The ensemble of calibrated fracture models is then used for uncertainty analysis, and a probability map of the spatial distribution of fractures is finally generated.

The power and utility of our approach are demonstrated using several applications. We first validate the streamline tracing algorithm for DPDK model by comparing its TOF with the result generated by the finite volume formulation of TOF generalized for compressible flow. Next, we validate the fracture identification workflow using a synthetic case by comparing the fracture probability map with the "true" fracture distribution. Finally, we apply our method to a DPDK model of a fractured reservoir and generate fracture probability map by calibrating multiple model realizations to well production and pressure data. The fracture probability maps serve as valuable tools to guide reservoir management and field development strategy.

The novelty of this work is the newly developed streamline tracing algorithm for DPDK models and the efficient workflow to generate fracture probability maps based on dynamic data. The proposed approach is easy to implement and can be coupled with commercial simulators for field scale applications.
First Ever Polymer Flood Field Pilot to Enhance the Recovery of Heavy Oils on Alaska North Slope – Producer Responses and Operational Lessons Learned
Authors: Ning Samson , Barnes John , Edwards Reid , Schulpen Walbert , Dandekar Abhijit , Zhang Yin , Cercone Dave , Ciferno Jared
Published: October 2020

The US Department of Energy and Hilcorp Alaska, LLC are jointly cosponsoring a field pilot project entitled "First Ever Field Pilot on Alaska’s North Slope to Validate the Use of Polymer Floods for Heavy Oil Enhanced Oil Recovery (EOR)." The objective of this pilot is to perform a field experiment to validate the use of an advanced polymer flooding technology to unlock the vast heavy oil resources on Alaska North Slope (ANS). Two pairs of horizontal injection and production wells have been deployed in an isolated fault block of the Schrader Bluff heavy oil reservoir at the Milne Point Field to conduct a polymer flood pilot which was designed to acquire field performance data to optimize polymer flood design in the Schrader Bluff heavy oil reservoirs on ANS. Hydrolyzed polyacrylamide (HPAM) polymer injection started on August 28, 2018 using a custom made polymer mixing and pumping unit. Polymer solution properties such as concentration, viscosity, and filter ratio, have been closely monitored and adjusted as necessary. Operational procedures have been improved to ensure adequate injectivity and polymer propagation through the formation. Oil and water production is tested frequently to monitor water cut performance, and produced water is sampled and analyzed for polymer content. Tracers were pumped pre and post polymer injection startup to compare polymer flood breakthrough timing and sweep efficiency.

Polymer injectivity of the horizontal wells drilled in the Schrader Bluff NB sand is found to be sufficient to replace the reservoir production voidage although there were some declines as high viscosity polymer swept the near wellbore region. Production data show significant reduction in water cut and increase in oil production rate. No polymer production has been confirmed from the two horizontal producers after 23 months of polymer injection into the two supporting horizontal injectors. Tracer data show very low sweep efficiencies with waterflood alone, whereas significant improvement has been achieved with polymer flood. Many operational lessons have been learned and improvements have been made regarding polymer mixing, pumping, and onsite quality control, particularly in a challenging Arctic environment. Adequate polymer injection rate can be achieved with diligent monitoring and quality assurance of the properties of the injected polymer solution.
New Type Curves for Horizontal Well Rate Transient Analysis and Their Field Application
Authors: Su Chang , Zhao Gang , Cai Hua , Xiao Lei , Shen Xiaohong , Lu Kefeng , Yuan Wanju
Published: October 2020

This paper presents three sets of new integrative production decline type curves for the analysis of horizontal well production data in order to systematically estimate reservoir flowing capacity (kh), effective horizontal wellbore length and original oil/gas in place. In addition, diagnostics of dynamic flow regimes possible for the entire flow duration from early time transient to late time boundary dominated flow gives the proposed type curves unique value in field data analysis through using different idealized flow regimes as the reference systems. Comparing to the traditional classic type curves, these three sets of type curves offer more practical implemental strategy for well performance evaluation and reservoir formation characterization, resulting in less ambiguity in the outcome of data interpretation. The effects of horizontal wellbore length and reservoir geometry on the appearances and the characteristics of these three sets of new type curves are studied and documented. A detailed curve matching process has also been comprehensively developed to achieve systematically proper matching with field data using all of the three sets of type curves synchronously.

To showcase this work in field application, the production dynamics of a gas field containing two vertical non-commingled units, each being produced by a horizontal well independently, is analyzed using the three sets of new type curves. With successful estimation of the kh and the effective horizontal wellbore length, it helps geologists and geophysicists locate the "sweet spot" with more confidence and offer the potential to extend the seismic response pattern to support further exploration activity in this geology unit. The outcome of this work helped identify the existence of an untapped gas reserve in the lower unit, thus to promote the potential of infill drill to enhance ultimate gas recovery.
Multiphase Transient Analysis of Flowback and Early Production Data of Unconventional Gas Wells
Authors: Nguyen Kien , Zhang Miao , Garcez Jonathan , Ayala Luis F.
Published: October 2020

Analysis of fracturing water flowback data from hydraulic fractures in unconventional reservoirs plays an important role in determining key fracture properties and predicting future well performance. Current flowback data analysis tools mostly rely on empirical correlations and/or simplified models. This paper presents a semi-analytical, multiphase solution that is applicable to the analysis of not only water flowback but early gas production data of multi-fractured horizontal gas wells. The proposed solution couples a Green's function-based analytical solution for gas flow in matrix with a finite-difference numerical solution for two-phase (gas and water) flow in fracture domain. The validity of proposed semi-analytical solution is verified against simulation results generated using commercial numerical simulators. Inverse analysis techniques are developed based on the proposed semi-analytical solution and presented in the form of type curves. Synthetic case studies show that the proposed type-curve methods can provide explicit and accurate estimation of fracture and reservoir properties, including fracture conductivity, and fracture pore volume. For all case tested, the proposed model is shown to provide accurate and consistent prediction of reservoir performance and estimations of fracture properties while maintaining the simplicity of explicit, iteration-free calculations.
Evolution of Three Dimensional Fluid Phase Connectivity During Injection
Authors: Ganguly Eliza , Misra Siddharth , Wu Yaokun
Published: October 2020

The three-dimensional connectivity of the fluid phases in porous media plays a crucial role in governing the fluid transport, displacement, and recovery. Accurate three-dimensional quantification of the fluid phase connectivity following each fluid injection stage will lead to better understanding of the efficacy and efficiency of the fluid injection strategies. Two metrics for measuring the connectivity in 3D show robust performance; one uses fast marching method to quantify average time required for a monotonically advancing wave to travel between any two pixels and the other uses two-point probability function to approximate the average distance between any two connected pixels belonging to the same fluid phase. The two connectivity metrics are applied on the three-dimensional (3D) CT scans of one water-wet Ketton whole-core sample subjected to five stages of multiphase fluid injection to quantify the evolution of the three-dimensional connectivity of the three fluid phases (oil, water, and gas). The water-wet Ketton carbonate sample (4.9 mm in diameter and 19.5 mm in length) is subjected to five sequential stages of fluid injection: 100%-brine-saturated sample, oil injection, water-flooding #1, gas injection, and water-flooding #2. CT-scan of the core sample was acquired after each injection stage. The metric response for oil phase connectivity drops after each injection process, denoting a reduction in oil connectivity after each fluid injection. The spatiotemporal variations in the connectivity of a fluid phase help understand the fluid displacement across pores of varying sizes depending on the wettability.
Real Time Reservoir Fluid Log from Advanced Mud Gas Data
Authors: Hafidz Arief Ibnu , Yang Tao
Published: October 2020

In a recent paper (Yang et al., 2019a), we published a machine learning method to quantitatively predict reservoir fluid properties from advanced mud gas (AMG) data. This approach has clear advantages due to early access, low cost, and a continuous reservoir fluid prediction for all reservoir zones. In this paper, we demonstrate how real time reservoir fluid logs are generated and compare the results with PVT samples or production data from the same well.

We develop a workflow of generating reservoir fluid logs from AMG data and PVT database. The workflow consists of two main processes; first a quality assessment of AMG data and second the computation of reservoir fluid properties (in this paper we use gas oil ratio). The entire workflow is written in python and embedded into existing commercial petrophysics softwares. The final product of the workflow are three log tracks which we call the reservoir fluid logs and those are 1) the concentration readings of the AMG data, 2) the QC metric score, and 3) the predicted GOR log. These three logs are plotted together with other standard open hole logs such as gamma ray, neutron-density, sonic and resistivity log to get a more comprehensive formation evaluation.

Reservoir fluid logs derived from AMG data has two main advantages. First, it is the only approach to acquire continuous reservoir fluid properties along the well path. The continuous fluid profile can be used to understand the variation of reservoir fluids in both vertical and lateral direction. The second advantage is that the reservoir fluid log is obtained while drilling and therefore the information can be used to optimize the drilling process or the downhole sampling program during wireline operation.

In this paper, we demonstrate the application of the reservoir fluid logs in four conventional field cases. In the first study case we show the benefit of using the reservoir fluid logs in a horizontal well as a substitute for downhole fluid sampling. In the second case study, we demonstrate how the reservoir fluid log is utilized to optimize the downhole fluid sampling program which results in reducing the subsurface uncertainty. Next, we exhibit the use of the reservoir fluid logs to locate gas oil contact in a case where pressure data does not show clear distinction of gas and oil gradient in the reservoir. In the last example, we illustrate the use of reservoir fluid knowledge from AMG to characterizing the fluid variation across a field. The field applications demonstrate the success of the new method for conventional reservoirs, provided good-quality AMG data are available.
Rapid Production Forecasting with Geologically-Informed Auto-Regressive Models: Application to Volve Benchmark Model
Authors: Mohd Razak Syamil , Jafarpour Behnam
Published: October 2020

Reliable hydrocarbon production forecasting is necessary for optimizing field development and management and for assisting asset teams in making sound business decisions. In conventional reservoir modeling workflows, the data used to build a subsurface flow model comes with inherent uncertainties that are typically represented by, and propagated through, a set of prior model realizations. History matching, which is used to generate a set of calibrated reservoir models, typically involves repeated runs of computationally intensive forward simulations. For many existing automated history matching workflows, production data scarcity and its non-linearity with respect to reservoir input model parameters complicate the formulation and solution of model calibration problems. Additional complexities of the model calibration workflows include ensuring geologic realism (plausibility) and assessing the uncertainty of the solution and the resulting forecasts. Short-term predictions that can be used to inform daily operational decisions may be more conveniently derived from data-driven models without relying on complex integrated reservoir models and the related complex workflows. In this paper, we develop spatial autoregressive models to obtain short-term data-driven prediction models. To this end, the injectors and producers in a reservoir are related through a set of weights that can be interpreted as their lumped connectivity information, which may be initialized with prior geologic knowledge, whenever available. Each element in the matrix dictates the existence and strength of connectivity between any injector-producer pair. The well connectivity depends on the spatial geologic features within the reservoir, such as heterogeneity and compartmentalization induced by stratigraphic trap, faulting and diagenesis. As more dynamic data becomes available, the connectivity matrices are continuously updated to derive new forecast in a manner similar to the history matching process. When data is not sufficient to resolve the uncertainty in connectivity information, alternative scenarios may remain plausible. However, when additional information about inter-well connectivity is available, it can be imposed to reduce the uncertainty in inter-well connectivity. The model presents a practical tool that can be applied to evaluate and rule out certain inter-well connectivity scenarios and address what-if questions. We present the model and discuss its properties with both synthetic and field-scale examples.
Nanoengineered Cement for More Effective Remedial Cementing Jobs
Authors: Tabatabaei Maryam , Dahi Taleghani Arash
Published: October 2020

The success of remedial cementing jobs is crucial, as its failure, not only may further damage the well, but also may lead to the total loss of wellbore. Therefore, it becomes necessary to develop reliable technologies to make these treatments operationally and economically more effective. Obviously, more effective cementing materials would improve the chance to address any integrity issues related to presence of microannulus. We present a novel solution by engineering the cement at the material scale to carefully adjust its rheology and mechanical properties to sneak into narrow opening and develop stronger bonding with pre-existing cements. We seek for better penetration into narrow spaces behind the casing with appropriate thickening time, low set-cement permeability, and high strengths. The outcome could provide an economic solution although involved with manipulating cement properties at the molecular scales.
Automated Solids Content Determination in Drilling and Completions Fluids
Authors: Gul Sercan , Karimi Vajargah Ali , van Oort Eric , Leulseged Amare , Cayeux Eric
Published: October 2020

Monitoring of low- and high-gravity solids (LGS and HGS) content and maintaining these at ideal levels is essential for the optimum drilling fluid performance, efficient hole cleaning and ECD management, as well as preventing failures of surface and downhole equipment during drilling. LGS and HGS monitoring in the field is currently accomplished using the API retort measurement, which has certain drawbacks and is difficult to automate. In this paper, alternative approaches to solids characterization are presented that lend themselves much better to automation and real-time monitoring.

Two new approaches were investigated to automate the LGS and HGS content measurements of drilling fluids, which can potentially replace the retort test in the future. In the first approach, extensive lab experiments were conducted to generate a controlled dataset that includes fluid rheological properties and density changes by the addition of various levels of LGS and HGS. Using this dataset, multi-linear, Ridge, Lasso, K-nearest neighbors (KNN), and Random Forest (RF) regression models were trained and tested to predict LGS and HGS content of drilling fluids. A key advantage of this machine learning (ML) approach is that these fluid properties can be obtained in real-time with measurements that are relatively simple and easy to automate. In the second approach, X-Ray Fluorescence (XRF) was used to generate calibration curves for various common solids used in drilling fluids (i.e., barite, clays, salts). This method also lends itself well to automation with real-time inline measurement.

Side-by-side tests of various fluids were performed using the API retort measurement, the ML approach, and the XRF sensor. It was observed that the API retort measurement can provide erroneous LGS and HGS content estimations. On the other hand, the trained ML regressor provided results with an average absolute error of only 0.3%. It was also observed that with the XRF measurements, distinct solids can be tracked highly selectively by quantifying the concentration of their specific elemental compounds (i.e., barium for barite concentration, silicon for sand concentration, iron for clay concentration). A detailed comparison of the three methods (API retort, ML, and XRF) is provided, clearly showing the advantages of the ML and XRF approaches over the older retort method.

The technology described here opens the doors to automated mud monitoring, maintenance, and solids control operations, which can assist with real-time solids content management and optimization. This will benefit downhole ECD management, hole cleaning optimization, ROP improvement and reduced equipment failure, resulting in safer wells drilled at lower costs.
Experimental Analysis of Alkali-Brine-Alcohol Phase Behavior with High Acid Number Crude Oil
Authors: Magzymov Daulet , Clemens Torsten , Schumi Bettina , Johns Russell T.
Published: October 2020

A potential enhanced oil recovery (EOR) technique is to inject alkali into a reservoir with a high total-acid-number (TAN) crude to generate soap in situ and reduce interfacial tension (IFT). The method may be cost-effective if the IFT can be lowered enough to cause significant mobilization of trapped oil, while also avoiding formation of gel/viscous microemulsions.

This paper investigates the potential field application of injecting alkali to generate in situ soap and favorable phase behavior for a high TAN oil. Oil analysis results show that the acids in the crude are a complex mixture of various polar species and not mainly carboxylic acids. Phase behavior experiments show that the system does not undergo typical Winsor microemulsion behavior. Therefore, traditional microemulsion models can cause unreliable recovery estimates. The mixing of alkali and crude/brine can generate water-in-oil macroemulsions that are highly viscous instead of forming the classical Winsor types. Good core flood recovery cannot be explained by the formation of a Winsor microemulsion phase, as is expected in surfactant EOR, mainly because these macroemulsions form before such idealized phase behavior can occur. A substantial decrease in interfacial tension is observed without the formation of a viscous phase in a narrow window of alkali concentration. Corefloods with polymer perform well in this concentration range, although incremental recovery could be overestimated some owing to increased water solubility in oil within these macroemulsions.

The viscous phase behavior at large alkali concentrations is likely explained by the formation of salt-crude complexes, created by acids from the crude oil under the alkali environment. These hydrophobic molecules tend to agglomerate at the oil-water interface. Together with polar components from the crude oil, they can organize into a highly viscous network and stabilize water droplets in the oleic phase. Oil-soluble alcohol was added to counter those two phenomena at large concentrations, but typical Winsor phase behavior was still not observed. A physicochemical model is proposed to explain the salt-crude complex formation at the oil-water interface that inhibits classical Winsor behavior.
Unique Real and Relevant Time Formation Evaluation: A Case Study from the Gulf of Mexico with Innovative Advances in Logging While Drilling
Authors: Kenning Kevin , Parker Jay , Murray Roger , Durrant Jeff , Watcharophat Hathairat , Vallega Valentina , McCall Rory , Shrivastava Chandramani
Published: October 2020

This case study presents a success story of a development well in the Gulf of Mexicodrilled with oil-based mud, with latest high-definition borehole image and comprehensive formation evaluation-while-drilling suite. Historical data from multiple offset wells suggested that the standardresolution petrophysical logs were insufficient to accurately evaluate this low-resistivity, low-contrastreservoir. The presence of salt intrusions compromises the surface seismic interpretation and poseadditional geological challenges, adding uncertainty to the oil water contact—which, if incorrectlyidentified, would cause early water production and compromise the success of the well.

Deploying a unique, high-resolution dual-physics imaging-while-drilling system and the advanced petrophysical LWD logging suite for the first time in this field was critical toachieving the optimal reservoir characterization and making subsequent operational decisions. Real-timecapture-spectroscopy and sigma measurements were essential to evaluate the mineralogical compositionand saturation estimation. Water saturation computed from sigma gives an estimate of free- and bound fluid volume, independent of the resistivity measurement, which showed little contrast betweenhydrocarbon- and water-filled formations.

The real-time transmission of apparent resistivity images enabled the identification and interpretation of the low-resistivity low-contrast reservoir, which appeared to be comprised of cross-bedded, sand-silt laminated facies. High-definition borehole images detected features such as fine lamination and fractures, which were not possible to be identified with the standard-resolution logging suite previously deployed in this field. This information provided an insight into the reservoir architecture and possible extent of the depositional facies vertically and laterally. The ultrasonic high- and low-frequency borehole images further helped refine the understanding of reservoir architecture in relevant time to aid in completion design. Additionally, the apparent resistivity derived from the high-definition resistivity provided a proxy to ultra-shallow resistivity that was able to identify the movable fluid in the reservoir when compared to standard resistivity measurements in singular drilling pass and confirmed the oil-water contact which were a critical information for well completion design

This case study demonstrates the integration of petrophysics and geological interpretation of comprehensive LWD logging which has been fundamental to resolve the reservoir characterization uncertainties and optimizing the completion strategy in a challenging low resistivity reservoir in one drilling run with real-time transmission of high-quality data.
Managing to Bring Appropriate Full Field EOR Production Profile Into Decision Making of Field Application From Notional Stage
Authors: Yonebayashi Hideharu , Iwama Hiroki
Published: October 2020

Full field production profile is needed to evaluate enhanced oil recovery (EOR) option and to progress the EOR project. In general, the methodology of full-field profile estimation highly depends on the objective case: field development maturity level, technology readiness level of the EOR option to be planned, etc. Therefore, this paper is facilitating how we should select an adequate methodology to estimate full-field EOR profiles through comparison of four case studies.

Case-1 was picked up as an example of type curve method based on sector models for water alternating gas (WAG) application using CO2 or hydrocarbon miscible gas. Case-2 represented a full-field simulation approach to incorporate facility capacities into account adequately because of produced gas re-injection (i.e. gas EOR). Case-3 demonstrated to use the identical flow model, which was history-matched with long production records, for estimating a new CO2 foam EOR technology which was unavailable as option in the identical commercial simulator. The last Case-4 dealt an emerging microbial EOR/EGR process without any commercial simulator and no pilot data yet.

In Case-1, two type curves were generated to represent typical geologies in the objective field: homogeneous and heterogeneous areas. After sensitivity studies using the simple sector models to optimize each parameter, type curves were obtained from the detailed sector models. The type curves, assigned in corresponding areas, were summed to estimate full-field profile. In Case-2, even full-field simulation is debatable in general due to huge workload and computation, it still has important role to evaluate gas EOR with limited gas processing capacity because to ignore the facility limits might mislead to optimistic conclusion. In Case-3 in the mature field, the history-matched model was already established by a commercial simulator. Unfortunately, the simulator does not have an exact option to evaluate our emerging CO2 foam technology while available for the conventional foam EOR using surfactant as foaming agent. Thus, we managed to handle our EOR technology by matching laboratory experimental outputs with pseudo-calculated gas mobility reduction ratio. In Case-4, another emerging microbial EOR technique was estimated analytically even only laboratory experimental data was available. Any commercial simulator is not available, either. The unique approach took essence of experimental outputs into a well type curve, and then full-field profile was estimated.

Each workflow has pros/cons, and an adequate one should be selected. However, in usual, a unique workflow is just applied to estimate full-field profile in the evaluation of objective EOR option. Furthermore, there has been little discussion of workflow selections from the aspect of development stage, EOR technological emerging level, and evaluation tool availability. This paper can provide ideas to consider guidelines for generating full-field profiles.
Reservoir Characterization and Geostatistical Model of the Cretaceous and Cambrian-Ordovician Reservoir Intervals, Meghil Field, Sirte Basin, Libya
Authors: Masoud Mohamed , Meddaugh W.Scott. Scott , Masud Masud Eljaroshi
Published: October 2020

Reliable and representative models and detailed characterization of a geologically complex reservoir are crucially important in having better understanding of the reservoir behavior and directly guiding to the most efficient implementation of the field development plan. This study focused on developing models of the Upper Cretaceous Waha carbonate and Bahi sandstone reservoirs and the Cambrian-Ordovician Gargaf sandstone reservoir in the Meghil field, Sirte Basin, Libya. The goals of the study were to characterize the vertical and lateral spatial continuity of each of the three formations and to calculate deterministic and probabilistic volumetrics.

The Meghil Field, discovered in 1959, is located on the Zelten Platform and regionally classified as an extensional area of the larger Zelten field. Nineteen wells were drilled targeting the primary reservoir interval of interest at a drilled depth of around 8000 feet. A 3D seismic program was conducted to develop detailed structural maps for the Kalash and Waha/Bahi/Gargaf formations to evaluate future gas field development program. The field is characterized by three slightly asymmetrical anticlinal traps trending NW-SE. Major and minor faults that cut the interior of the structure were detected in the seismic block. The available drill stem DST and production tests were used to evaluate the level of communication between the structures. The structural framework for a 3D reservoir model is based on the interpretation and integration of the seismic volume and the available well logs.

The well log data show that the net hydrocarbon bearing zone thickness is about 270 feet, the average porosity ranges from 4% in the Bahi/Gargaf sandstone to 13% in the Waha limestone. The average water saturation ranges from 15% to 32% in the Waha limestone and the Bahi/Gargaf sandstone respectively. Geostatistical models were developed using the well log and core data along with the structural model developed from the 3D seismic volume. The models suggest that porosity decreases towards the flanks and that separate flow units are likely present. The deterministic and stochastic give estimates of the original gas in place of about 830 Bscf and 732.2 Bscf for the upper and lower reservoir intervals, respectively. This study demonstrated the potential for significant additional hydrocarbon production from the Meghil field as well as the potential impact of heterogeneity on well placement and spacing.