bluuebunny/crossref_metadata_2025 huggingface dataset:
The Implementation of the POPMAR (Policy, Organising, Planning and Implementing, Measuring Performance, Audit and Reviewing) Model in Occupational Health and Safety Risk Management in an Indonesian Batik Company
Authors: Maharani Fandita Tonyka , Lynch Zena
Published: November 2021

Introduction: In 2009, UNESCO declared Batik Indonesia as an Intangible Cultural Heritage of Humanity. This study examines the occupational health and safety hazards and risks that arise in a Batik company based on a case example of a Batik company in Surakarta, Indonesia. In Indonesia, Batik is categorized as traditional attire. Two kinds of Batik are produced - Batik tulis (traditionally handcrafted) and Batik printing, which uses specific printing tools. The UK Health Safety Executive (HSE) risk assessment framework is referred to in this study, which consists of: hazard identification, population exposure, risk evaluation, precaution development, recording findings, and regular appraisal of systems. Methods: Both observation and interviews (of workers) at the Batik company were utilized for this study as well as an independent risk assessment. Results: The findings highlighted physical, ergonomic, chemical, mechanical, and biological hazards, originating from the materials, tools, and working methods utilized in the batik production. Conclusion: Many of the issues highlighted by this study can be addressed via in-depth risk assessment, using the POPMAR model to frame the activities. This approach can create a positive pathway, leading to a continuous cycle of improvement which puts the workers’ health at the forefront of the business activities.Keywords: Batik, workers, hazard identification, HSE Model, risk management
THE EFFECT OF INTERVENTION PROGRAMS ON HOW TO WORK COMPLAINTS IN MECHANICAL WORKERS IN HEAVY EQUIPMENT COMPANIES
Authors: Ilyas Muhammad , Soffiudin Muhammad , Adi Nuri Purwito , Sulistomo Astrid , Kekalih Aria
Published: November 2021

ABSTRACTLow back pain (LBP) is experienced by almost everyone during his life, and data in Indonesia ranged from 3-17% based on hospital records. LBP can occur due to awkward body postures and manual handling during working and need intervention to reduce complaints. This study to know intervention to reduce risk at ergonomic can induce LBP. This study uses a quasi-experimental design using control with a sample of 35 in each group. The intervention program monitoring was carried out by the SHE team at the work site based on conducting weekly observations regarding workers doing awkward work postures and manual handling activities and ensuring that mechanical workers receive ergonomics training. After one year of the intervention program, the data collection was carried out using a questionnaire to find out the changes in the length of the squat position, bending position, and manual handling activities in both groups. Significant differences between the two groups were obtained in the long work category with squat posture with p-value <0,001, bent posture with p-value 0.001, and a non-significant difference were found in the manual handling category with a p-value of 0.614. The intervention program can change manual handling in the intervention group 3.6 times at work duration more than 1 hour in a squatting position and decrease in the length of bending position more 1 hour by 1.4 times compared to control. Keywords: ergonomic training, squatting position, bending position, manual handling.
Do Accounting, Market, and Macroeconomic Factors Affect Financial Distress? Evidence in Indonesia
Authors: Taufik Muhammad , Sugianto Clarita Valeria
Published: November 2021

This paper aims to investigate the effect of accounting, market, and macroeconomic factors on financial distress. The investigations were expanded by constructing seven research models to simulate all factors. The research sample includes companies listed on the IDX from 2016 to 2020 which produce 1.710 data. This paper finds that retained earnings (RETA) and earnings (EBITTA) as part of accounting factors have a role in weakening financial distress and can be consistently tested in several research models. Equity (MVE) as part of the market factor weakens financial distress and is consistently tested. Although solvency (SOLV) was described as the company's ability to maximize debt, it is not consistently tested in several research models. Finally, it was found that deflationary conditions caused financial distress which represented macroeconomic factors. This paper makes a practical contribution to companies and governments to evade financial distress
Falls As a Problem of an Aging Population, a Modern Look at Risk Factors and Assessment Methods. Role of Fear of Falls in Increasing their Risk
Authors: Larina V. N. , Samkova I. A. , Kudina E. V.
Published: November 2021

The article presents modern views on the problem of falls in the elderly. There is a global trend of changing the demographic situation - the permanent increase in the proportion of elderly and senile people in the general population, the issues of geriatrics as one of the medical specialties are becoming the most relevant. Among the problems that geriatricians and all specialists involved in the treatment of elderly patients have to solve, one of the most serious is the problem of falls. The article provides a medical review of the assessment of the frequency of falls depending on gender, age, diseases and external factors. The main risk factors for falls and their prevention measures are discussed in detail. Special attention is given to the fear of falls as a significant risk factor. The methods of validation the risk factor with the use of unified questionnaires - “The scale of assessment of the fear of fa lls” and “the Falls efficacy scale” are presented. The purpose of this article is to attract the attention of practitioners to the problem of falls and the fear of falls as one of the significant risk factors, methods of its identification and prevention
Editorial
Authors: Castelo Branco Judikael , Alexandre Nicolau Marcos Fábio
Published: November 2021

Editorial Perspectivas v. 6, n. 1
Presentimento di una religione senza dio in Friedrich Feuerbach
Authors: Andolfi Ferruccio
Published: November 2021

O artigo trata da hipótese de que nos escritos de Friedrich Feuerbach sobre a a religião do futuro e sobre a igreja do futuro, possamos encontrar elementos de reflexão úteis para a articulação do tema, hoje tão discutido, de uma religião sem deus. De um lado, esse exercício sublinha a perspectiva humanista da filosofia em questão e, por outro, destaca a necessidade da criação de uma nova forma de laço capaz de difundir uma fé que una os homens com um vínculo mais forte que o vínculo do cristianismo, isto é, que promova e sustente a aspiração, que nos nossos dias se manifesta de modos diversos, a integrar as insuficiências das forças individuais com um espírito comum. Trata-se sempre do amor do próximo fundado sobre a nossa “natureza comum”, particularmente sobre a recíproca necessidade que experimentamos uns dos outros e que nos leva a considerar-nos “irmãos e irmãs no homem”.
Modernidade e democracia
Authors: Castelo Branco Judikael
Published: November 2021

O artigo articula modernidade e democracia a partir da análise dos registros políticos da linguagem na obra de Eric Weil. A ideia de modernidade é tomada da descrição weiliana da sociedade moderna, vista por ele como calculista, materialista, mecanicista e mundial, características que não apenas põem em oposição a sociedade e as comunidades históricas, mas que exercem uma pressão não indiferente sobre os indivíduos. Naturalmente, esse quadro tem imensas repercussões sobre as nossas democracias. A análise dos registros políticos da linguagem nos leva a considerar o papel do discurso e da discussão nas democracias, mas, sobretudo, a pensar a importância do diálogo como linguagem política em “sentido forte”, cuja retomada se torna particularmente urgente no cenário político atual.
A APROPRIAÇÃO DA NARRATIVA JORNALÍSTICA PELAS FAKE NEWS
Authors: Ferreira Josué
Published: November 2021

Este artigo faz uma discussão teórica sobre a narrativa jornalística e como ela tem sido apoderada pelas fake news. Utilizamos o conceito de narrativa baseado em alguns autores como Barthes e Motta, e discorremos sobre como essa estrutura é emprestada da literatura para o jornalismo e, agora, para a desinformação. Busca-se debater como as fake news estão ligadas diretamente à constituição do indivíduo devendo, portanto, ser tratada como uma prática cultural que toma forma e cresce a cada momento. Por fim, reforça a necessidade de munir o jornalismo de ferramentas diárias para enfrentar essa prática maléfica, principalmente durante a pandemia da Covid-19, em que o jornalismo se mostra essencial para evitar, inclusive, mortes devido à desinformação.
The Evolution of Hox Genes in Spiralia
Authors: Hejnol Andreas , Gasiorowski Ludwik , Martin-Duran Jose-Maria
Published: November 2021

The decoding of genomes of a larger number of animal species have provided further insights into the genomic Hox gene organization and with this indicated the evolutionary changes during the radiation of several clades. The expansion of gene expression studies during development and life history stages of more species, complete the picture of the relationship between cluster organisation and temporal and spatial correlation of the Hox activity. Now these results open the opportunity to look deeper into the regulatory pathways that form these patterns and identify what exact changes caused the evolution of the application of this iconical gene set for the evolution of new larval forms and new structures. Here we review recent progress of Hox gene related research in the large clade Spiralia, that comprises Annelida, Mollusca, Lophophorata, Platyhelminthes, Nemertea and others. Albeit their relationship to each other is not resolved yet, there are emerging patterns that indicate that Hox genes are mainly used for patterning late, adult body parts and that Hox genes are often not expressed on the larval stages. Hox genes seem also often recruited for the formation of morphological novelties. Together with the emerging genomic information Hox genes show a much more dynamic evolutionary history than previously assumed.
Multimodal Social Network Dataset Based on Goldbach Conjecture Proved Event in Zhihu
Authors: Liu Tingzhen , Geng Shijie , Huang Zhiquan , Wu Senxin , Wang Zixi
Published: November 2021

At the end of 2018, a high school student asked a question in Zhihu community, claiming that he had proved Goldbach's conjecture. The problem caused an explosive reaction and a large number of users participated in the discussion. And has caused the widespread influence. On January 1, 2019, the questioner issued his "proof". His proof was soon proved wrong. The heated discussion caused by the incident contains a lot of information of social science analysis value. Therefore, we follow up the event in the first time and build a time series dataset for the event. Taking the questioner's "proof" as the dividing line, all the answers, comments, sub comments and user information of writing these texts before and after two days were recorded. This series of temporal information can reflect the dynamic features of the interaction between user opinions, and the impact of exogenous shocks (proof release) on community opinions. The dataset can be used not only for the demonstration of various social network analysis algorithms, but also for a series of natural language processing tasks such as fine-grained sentiment analysis for long texts, as well as multimodal tasks combining natural language processing and social network analysis. This paper introduces the characteristics and structure of the dataset, shows the visualization effect of social network, and uses the dataset train the benchmark model of emotion analysis.
Fluoroscopic 3D Image Generation from Patient-Specific PCA Motion Models Derived from 4D-CBCT Patient Datasets: A Feasibility Study
Authors: Dhou Salam , Alkhodari Mohanad , Ionascu Dan , Williams Christopher , Lewis John H.
Published: November 2021

A method for generating fluoroscopic (time-varying) volumetric images using patient-specific motion models derived from 4-dimensional cone-beam CT (4D-CBCT) images is developed. 4D-CBCT images acquired immediately prior to treatment have the potential to accurately represent patient anatomy and respiration during treatment. Fluoroscopic 3D image estimation is done in two steps: 1) deriving motion models and 2) optimization. To derive motion models, every phase in a 4D-CBCT set is registered to a reference phase chosen from the same set using deformable image registration (DIR). Principal components analysis (PCA) is used to reduce the dimensionality of the displacement vector fields (DVFs) resulting from DIR into a few vectors representing organ motion found in the DVFs. The PCA motion models are optimized iteratively by comparing a cone-beam CT (CBCT) projection to a simulated projection computed from both the motion model and a reference 4D-CBCT phase, resulting in a sequence of fluoroscopic 3D images. Patient datasets were used to evaluate the method by estimating the tumor location in the generated images compared to manually defined ground truth positions. Experimental results showed that the average tumor mean absolute error (MAE) along the superior-inferior (SI) direction and the 95th percentile in two patient datasets were (2.29 mm and 5.79 mm) for patient 1 and (1.89 mm and 4.82 mm) for patient 2. This study has demonstrated the feasibility of deriving 4D-CBCT-based PCA motion models that have the potential to account for the 3D non-rigid patient motion and localize tumors and other patient anatomical structures on the day of treatment.
Malay, Islam, Beraja and The [Islamic] Educational Philosophy in Brunei Darussalam
Authors: Thoriquttyas Titis , Nasih Ahmad Munjin , Sultoni Achmad , Yani Achmad
Published: November 2021

The ideology of Brunei Darussalam contributes in shaping the [Islamic] Education system. Politically, Brunei applies the concept of Malay, Islam, Beraja (MIB) as an ideological basis. This research is oriented to two main discussions. First is the historical trajectory of MIB in Brunei and its relation to the education system. The second is the dimension of educational philosophy and Islamic education philosophy in Brunei by drawing its relation to the MIB. This research uses a qualitative-naturalistic approach. This research was conducted in Brunei, October 2019. Data was collected through interviews, focus group discussions (FGD), observation, document and literature studies. In data collection, this research involved academics from Kolej Universiti Perguruan Ugama Seri Begawan (KUPU) and Sultan Sharif Ali Islamic University (UNISSA). The findings show that the MIB is related to the model perennialism and progressivism. However, from Islamic education philosophy, MIB gives a traditionalist style to the mazhabi and modernist education system.
Negation and Implication in Quasi-Nelson Logic
Authors: Nascimento Thiago , Rivieccio Umberto
Published: November 2021

Quasi-Nelson logic is a recently-introduced generalization of Nelson’s constructive logic with strong negation to a non-involutive setting. In the present paper we axiomatize the negation-implication fragment of quasi-Nelson logic (QNI-logic), which constitutes in a sense the algebraizable core of quasi-Nelson logic. We introduce a ﬁnite Hilbert-style calculus for QNI-logic, showing completeness and algebraizability with respect to the variety of QNI-algebras. Members of the latter class, also introduced and investigated in a recent paper, are precisely the negation-implication subreducts of quasi-Nelson algebras. Relying on our completeness result, we also show how the negation-implication fragments of intuitionistic logic and Nelson’s constructive logic may both be obtained as schematic extensions of QNI-logic.
A Conﬂict Tolerant Logic of Explicit Evidence
Authors: Studer Thomas
Published: November 2021

Standard epistemic modal logic is unable to adequately deal with the FrauchigerRenner paradox in quantum physics. We introduce a novel justiﬁcation logic CTJ, in which the paradox can be formalized without leading to an inconsistency. Still CTJ is strong enough to model traditional epistemic reasoning. Our logic tolerates two diﬀerent pieces of evidence such that one piece justiﬁes a proposition and the other piece justiﬁes the negation of that proposition. However, our logic disallows one piece of evidence to justify both a proposition and its negation. We present syntax and semantics for CTJ and discuss its basic properties. Then we give an example of epistemic reasoning in CTJ that illustrates how the diﬀerent principles of CTJ interact. We continue with the formalization of the Frauchiger–Renner thought experiment and discuss it in detail. Further, we add a trust axiom to CTJ and again discuss epistemic reasoning and the paradox in this extended setting.
A Tale of Excluding the Middle
Authors: Beall Jc , Priest Graham
Published: November 2021

he paper discusses a number of interconnected points concerning negation, truth, validity and the liar paradox. In particular, it discusses an argument for the dialetheic nature of the liar sentence which draws on Dummett’s teleological account of truth. Though one way of formulating this fails, a different way succeeds. The paper then discusses the role of the Principle of Excluded Middle in the argument, and of the thought that truth in a model should be a model of truth.
Default Negation as Explicit Negation plus Update
Authors: Kahle Reinhard
Published: November 2021

We argue that under the stable model semantics default negation can be read as explicit negation with update. We show that dynamic logic programming which is based on default negation, even in the heads, can be interpreted in a variant of updates with explicit negation only. As corollaries, we get an easy description of default negation in generalized and normal logic programming where initially negated literals are updated. These results are discussed with respect to the understanding of negation in logic.
Nano-Texturing of Hydrocarbon Reservoirs with Omniphobic Nanoparticles to Mitigate Liquid Phase Trapping
Authors: Sayed Mohammed , Saini Rajesh , Ow Hooisweng
Published: November 2021

Gas reservoirs contain substantial amounts of natural gas and, in some cases, associated high API liquid hydrocarbons. Condensation of heavy hydrocarbons, especially in the area closer to the wellbore, occurs as a direct result of the decline in reservoir pressure. This hydrocarbon condensate, and in some cases water, tends to accumulate in the pore space and form a liquid bank. This liquid bank will result in a reduction in gas relative permeability and overall reduction in the well's productivity. This paper illustrates the synthesis and utilization of surface modified silica nanoparticles to mitigate the liquid banking phenomenon in gas reservoirs.

Silica nanoparticles (S-NPs), of different sizes, were synthesized using the Stöber process. The impact of the nanoparticle size and degree of functionalization with different hydrophobic and omniphobic groups on altering the rock wettability properties to mitigate liquid banking in gas reservoirs were studied. The S-NPs (of sizes between 50-400 nm) were functionalized with various linear and branched fluoroalkyl groups, terminal amine, and epoxy groups. The particle size of surface modified silica nanoparticles was determined using dynamic light scattering (DLS). The performance of the surface modified silica nanoparticles was evaluated through measuring surface charge, change in contact angle, and by performing core flow experiments at reservoir conditions.

A glass slide dip coated with 135 nm surface modified silica nanoparticles solution derivatized with terminal amine and perfluoroalkyl group provided a contact angle of 120° and 83° with water and decane, respectively. The contact angle can be tailored by changing the amount of amine and perfluoroalkyl concentrations on the particle surfaces. A contact angle of around 90° indicates a nonwetting neutral surface that results in minimizing capillary pressure and enhancing mobility of both hydrocarbon and water liquid phases. Using core flow studies and by estimating the improvement in gas and liquid relative permeabilities, surface modified silica nanoparticles treatment demonstrated a comparable performance to commercially available solutions at 1/5 the treatment volume. The surface modified silica nanoparticles sustained its performance indicating a stable and permanent coating on the rock surface.

The silica nanoparticles functionalized with fluoroalkyl group, terminal amine and epoxy can be directly pumped without the need for a pretreatment of the rock surface. This results in less complexity when it comes to the field operation. The dual- functionalized silica nanoparticles were found to be effective in changing the rock surface wettability to neutral or nonwetting, thereby providing a potential solution to liquid banking problem in gas reservoirs.
Fate of Emulsifier in Invert Emulsion Drilling Fluids: Hydrolysis and Adsorption on Solids
Authors: Khramov Dimitri , Barmatov Evgeny
Published: November 2021

Emulsifier concentration in SBM is an important factor of drilling fluid stability. Proper concentration of amidoamine emulsifier is imperative for controlling low fluid loss and maintaining emulsion stability. This study investigates the physical and chemical interactions between emulsifier and other additives and describes the processes by which emulsifier is depleted from the drilling fluid. Three main pathways of emulsifier consumption are identified: emulsifier adsorption on solids found in drilling fluids and low gravity solids (LGS), chemical degradation, and to stabilize the invert emulsion.

Design of experiments model and analytical procedure based on 1H NMR (nuclear magnetic resonance) spectroscopy was used to quantify the required emulsifier concentration in Non-Aqueous Fluid system (NAF). Additionally, model systems were used to estimate the excess of emulsifier, evaluate the emulsifier losses due to alkaline hydrolysis at elevated temperature, and measure adsorption of emulsifier on barite and various LGS types. Calculations for emulsifier depletion based on model systems were correlated to performance of formulated drilling fluids for verification.

Typical emulsifier requirement in high performance NAF is 8-12 pounds per barrel (ppb). Majority of the emulsifier is adsorbed on weighting agents (barite) and rheology modifiers (clays), which are used to formulate NAF, that contribute to their effective dispersion in the solution and control fluid rheology. The adsorption process is found to be sensitive to the emulsifier concentration, solids mineralogy, wetting agent and temperature. Analytical Langmuir-Freundlich isotherm was used to describe adsorption data and estimate the adsorption capacity of the system. The emulsifier degradation pathway is another important factor of emulsifier consumption; however, emulsifier degradation at 250°F is not significant. While NAF are generally run ‘rich’ to mitigate depletion and maintain fluid stability, adsorption onto minerals will become an issue especially at high LGS concentration.

These results will be greatly beneficial in the further development of NAF drilling fluid formulations and will assist field engineers in understanding the effect excess emulsifier will have on the drilling fluid and enable them to more effectively control the fluid properties under variations in emulsifier and LGS concentration during drilling.
A Novel Epoxy Resin Composition as a Lost Circulation Material: Formulation, Lab Testing and Field Execution
Authors: Alanqari Khawlah , Wagle Vikrant , Al-Yami Abdullah , Mohammed Ali
Published: November 2021

The novel resin composition described in this paper has been designed to treat moderate to severe losses. The resin composition comprises an epoxy resin and a chemical activator that undergo a polymerization reaction without any addition of water. The polymerization was designed to delay and successfully controlled to gel up and form the target resin composition after the fluid goes inside the wellbore. This is very important to avoid early setting of the fluid. The objective of this paper is to discuss the formulation of epoxy resin as a lost circulation material and also detail the lab testing and field execution.

In this study, we used two different epoxy resins to study the development of the novel loss circulation material. One contains two epoxy groups and the other contains only one epoxy group. Two different chemical activators have been used in this study as well; each of them differs in the number of amine groups and geometry. The effect of these differences on the polymerization in terms of time and properties were investigated. In addition, the effect of the chemical activator concertation on the setting time of the resin composition was investigated to accomplish a controlled and a delayed polymerization. Also, the chemical conditions were evaluated to simulate a variety of downhole conditions to prove the effectiveness of this novel resin composition as a loss circulation treatment. The lab testing includes thickening time measurements.

The novel resin composition is designed to have a controlled thickening time under a variety of downhole conditions. This is important to have an accurate placement of the fluid inside the wellbore; thus, avoiding an early setting of the fluid. We found that the thickening time of the resin composition can be controlled by mainly varying the concertation of the chemical activator. We found as well that changing the type of epoxy resin or chemical activator produce different gelling time and properties. We designed the loss circulation composition to provide a predictable and controlled pumping time. This novel resin composition can remain in a liquid phase from a few minutes to several hours based on the desired conditions. This is favorable in order to have an accurate placement of the fluid inside the wellbore over a predictable and controlled period of time. The final and target resin composition, will appear and gel as a solid thereby preventing loss circulation.

The resin was pumped from the BHA in a single stage which helped mitigate and reduce the dynamic losses from 260 bbl./hr. to 200 bbl./hr. using only 25 bbls and eventually to zero.
Screening Friction Reducer Performance Using Zeta Potential
Authors: Ayazi Philip , Peregoy Nathan , Monreal Gabriel , Zamora Frank
Published: November 2021

Friction reducers (FRs) are essential additives for water used in hydraulic fracturing treatments for shale reservoirs. These polymers swell and unfurl in the frac water so that polymer chains align along the direction of flow to inhibit turbulence thereby reducing friction at high flow rates. Source water ion content, application pH, and compatibility with the formation are key drivers in deciding which FR chemistries are fit-for-purpose for the operation, balancing desired fluid performance with treatment economics. This investigation explores zeta potential measurement as a novel and meaningful analytical metric to correlate chemical and rheological properties of FRs in a range of source water qualities with their friction reducing performance. The approach of this investigation involves measuring zeta potential of frac fluids formulated using anionic or cationic FRs in waters with varying ionic activity over a range of FR concentrations and pH. The evaluation encompasses a variety of FRs spanning general purpose materials to more sophisticated additives designed to function in fluids with higher concentrations of salt. Dry FR materials as well as corresponding slurry or emulsion forms of the additives are tested. Monovalent and divalent salts and mixtures thereof are used in brine formulations. FR characterization is performed including rheological sweeps, viscoelasticity measurements, and flow loop tests. Results from this study support the conclusion that zeta potential measurement can be used during the FR screening process as a viable supplement to industry standard tests for assessing FR performance in brine.
Modeling Acid Fracturing Treatments in Heterogeneous Carbonate Reservoirs
Authors: Dong Rencheng , Wheeler Mary F. , Su Hang , Ma Kang
Published: November 2021

The goal of acid fracturing operations is to create enough fracture roughness through non-uniform acid etching on fracture surfaces such that the acid fracture can keep open and sustain a high enough acid fracture conductivity under the formation closure stress. A detailed description of the rough acid-fracture surfaces is required for accurately predicting the acid-fracture conductivity. In this paper, a 3D acid transport model was developed to compute the geometry of acid fracture for acid fracturing treatments. The developed model couples the acid fluid flow, reactive transport and rock dissolution in the fracture. We also included acid viscous fingering in our model since the viscous fingering mechanism is commonly applied in acid fracturing to achieve non-uniform acid etching.

Carbonate reservoirs mainly consists of calcite and dolomite minerals but the mineral distribution can be quite heterogeneous. Based on the developed model, we analyzed the effect of mineral heterogeneity on the acid etching process. We compared the acid etching patterns in different carbonate reservoirs with different spatial distributions of calcite and dolomite minerals. We found that thin acid-etched channels can form in carbonate reservoirs with interbedded dolomite layers. When the reservoir heterogeneity does not favor growing thin acid-etched channels, we investigated how to utilize the acid viscous fingering technique to achieve the channeling etching pattern in such reservoirs. Through numerical simulations, we found that thin acid-etched channels can form inside acid viscous fingers. The regions between viscous fingers are left less etched and act as barriers to separate acid-etched channels. In acid fracturing treatments with viscous fingering, the etching pattern is largely dependent on the perforation spacing. With a proper perforation design, we can still achieve the channeling etching pattern even when the reservoir does not have interbedded dolomite layers.
Chemical Flooding in Western Canada – Successes and Operational Challenges
Authors: Renouf G. , Bolton G. , Nakutnyy P.
Published: November 2021

Over the last 30 years, chemical flooding of oil reservoirs has been broadly adopted as a technique for enhanced and incremental oil recovery around the world. Western Canadian oil producers have embraced polymer flooding to recover heavy oil, but have applied other forms of chemical flooding more sparingly. This study examines 31 chemical floods - ASP, AP, SP, alkali, and nanosurfactant floods - from mostly heavy oil fields (20 heavy oil, 10 medium oil, and one light oil). The success of the chemical floods was related to over forty reservoir and operating parameters, including water quality. We also discuss the operational challenges common in western Canada.

Chemical flooding projects were identified through searches of government documents. Production and injection data were gathered using Accumap software; and reservoir and operating parameters were gathered from government documents and literature. Incremental recovery was calculated by performing decline curve analysis of the waterflooding production. The incremental recovery was the difference between the actual production during chemical flooding, and the predicted production had waterflooding continued rather than shifting to chemical flooding. Multivariate analysis was used to determine the most important parameters to the success of the chemical floods.

The incremental recoveries ranged from 0 to 22% of original oil-in-place (OOIP), or 0 to 44% of OOIP per pore volume. Twenty-three of the 31 floods improved their water-oil ratios (WOR) after the start of chemical flooding. Water quality was a significant issue to the success of the chemical floods, leading to problems that were not anticipated in the planning and development stages. Some case histories are discussed to better illustrate the best practices for chemical recovery of heavy and medium oils. Water sources, management, treatment and chemistry all pose significant challenges that are often not fully assessed before starting the chemical flood projects. The review highlights challenges common to chemical flooding of heavy oil, and discusses common effects experienced as a result of water and chemistry compromises.
Water-Based Nanofluid-Alternating-CO2 Injection for Enhancing Heavy Oil Recovery: Underlying Mechanisms that Influence its Efficiency
Authors: Cao Changxiao , Song Zhaojie , Su Shan , Tang Zihan , Xie Zehui , Chang Xuya
Published: November 2021

The efficiency of CO2 water-alternating-gas (WAG) flooding is highly limited in low-permeability heavy oil reservoirs due to the viscosifying action of W/O emulsification and high mobility contrast between oil and CO2. Here we propose a new enhanced oil recovery (EOR) process which involves water-based nanofluid-alternating-CO2 (NWAG) injection, and investigate the synergistic effect of nanofluid and CO2 for enhancing heavy oil recovery. Firstly, the oil-nanofluid and oil-water emulsions were prepared, and the bulk rheology and interfacial properties of emulsion fluid were tested. Then, core flooding tests were conducted to examine the NWAG flooding efficiency and its underlying mechanisms. The results showed that the bulk viscosity and viscoelasticity of oil-nanofluid emulsion reported much lower than those of oil-water emulsion, and nanofluid presented a positive contribution to the phase inversion from W/O to O/W emulsification. Compared with oil-water emulsion, the interfacial storage modulus of oil-nanofluid emulsion was obviously increased, which confirmed that more of crude oil heavy components with surface activity (e.g., resin and asphaltene) were adsorbed on interfacial film with the addition of silica nanoparticles (NPs). However, the interfacial viscosity of oil-nanofluid emulsion was much lower than that of oil-water emulsion, showing the irregularity of interfacial adsorption. This implied that the self-assembly structure of crude oil heavy component of the oil-water interface was destroyed due to the surface activity of silica NPs. During the core flooding experiments, NWAG injection could reduce the displacement pressure by 57.14% and increase oil recovery by 23.31% compared to WAG injection. By comparing produced-oil components after WAG and NWAG injection, we found that more of crude oil light components were extracted by CO2 during NWAG flooding, showing that the interaction between CO2 and crude oil was improved after oil-nanofluid emulsification. These findings clearly indicated two main EOR mechanisms of NWAG injection. One was the phase inversion during the nanofluid flooding process. The addition of silica NPs promoted phase-inversion emulsification and thus improved the displacement efficiency. The other was the enhanced interaction between CO2 and crude oil after oil-nanofluid emulsification. Because of the enhanced adsorption of crude oil heavy component on the oil-water interface, the proportion of light hydrocarbon increased in the bulk phase, and so the interaction between CO2 and oil phase was improved. This work could provide a new insight into the high-efficiency exploitation of low-permeability heavy oil reservoirs.
Ranking Anti-Agglomerant Efficiency for Gas Hydrates Through Molecular Dynamic Simulations
Authors: Mohr Stephan , Hoevelmann Felix , Wylde Jonathan , Schelero Natascha , Sarria Juan , Purkayastha Nirupam , Ward Zachary , Navarro Acero Pablo , Michalis Vasileios K.
Published: November 2021

Computational and experimental methods were employed to assess the capacity of four surfactant molecules to inhibit the agglomeration of sII hydrate particles. Using both steered and non-steered Molecular Dynamics (MD), the coalescence process of a hydrate slab and a water droplet, both covered with surfactant molecules, was computationally simulated. The experimental assessment was based on rocking cell measurements, determining the minimum effective dose necessary to inhibit agglomeration. Overall, the performance ranking obtained by the simulations and the experimental measurements agreed very well. Moreover, the simulations gave additional insights that are not directly accessible via experiments, such as an analysis of the mass density profiles or the orientations of the surfactant tails. The possibility to perform systematic computational high-throughput screenings of many molecules allows an efficient funnel approach for molecular optimization and customization.
Facile Fabrication of Nanoemulsions through the Efficient Catanionic Surfactants for Spontaneous Imbibition in Tight Oil Reservoirs: Experimental and Numerical Simulation
Authors: Wei Bing , Mao Runxue , Tang Haoran , Wang Lele , Wang Dianlin , Wang Yiwen , You Junyu , Lu Jun
Published: November 2021

Spontaneous imbibition (SI) is an essential method for accelerating mass exchange between fracture and matrix in tight oil reservoirs. However, conventional systems such as brine and surfactant solution have limited imbibition effects, so there is still abundant remaining oil in the matrix. Nanoemulsion holds the most promising potential in improving tight oil recovery owing to the favorable surface activity and nanoscale droplets, but it still lacks economic and facile methods to fabricate nanoemulsions. Therefore, in this paper, we prepared a kind of O/W nanoemulsion of catanionic surfactants with a low dosage of surfactant and energy consumption, which was then used to assess spontaneous imbibition performance in Changqing outcrop cores by experimental and numerical simulation. We have fully considered the possible imbibition mechanisms of nanoemulsion including wettability alteration, IFT reduction, solubilization and emulsification, etc., and successfully applied to the nanoemulsion imbibition model. The model and experimental data were found to be in good agreement. The results showed that the imbibition rate and oil recovery factor of the nanoemulsion in the first 100 hours are lower than that of brine. In the late stage, we observed a longer equilibrium time and a faster and higher oil imbibition process in nanoemulsion with ultralow IFT. Finally, we confirmed that solubilization and emulsification is one of the domiant mechanisms for nanoemulsion imbibition by comparing with the modelling without considering solubilization and emulsification.
Research on the Relationship Between Crude Oil Composition and Asp Flooding Effect
Authors: Sun Zhe , Kang Xiaodong , Zhang Shanshan
Published: November 2021

In recent years, ASP flooding has been widely applied and obtained the remarkable effect. During the ASP flooding process, the oil composition has a great effect on the interfacial tension, which plays a vital role in the oil displacement effect. However, through literature research, few have made a profound study on the effect of oil composition on the recover rate. As a result, it is very important to carry out relevant research.

For the oil sample (I) and sample (II) from two different regions in DQ, the crude oil composition analysis is first carried out. After the mixing of oil system and ASP system, the distribution ratio of agent is obtained. Furthermore, the oil composition does have an impact on the interfacial tension and recovery rate, and its influence law is explored. Finally, its application is introduced and analyzed.

Research results show that, compare with sample (II), the sample (I) has more heavy components. After the mixing of oil samples and ASP, more surfactant and alkali enters into the oil phase of sample (I). Therefore, based on the similar miscibility principle, the surfactant is more likely to leave the oil water interface and enter into the oil phase of sample (I), which has a negative effect on reducing the interfacial tension. Furthermore, the phenomenon of chromatographic separation aggravates the adsorption of surfactant on rock surface. Therefore, combining the above factors, the oil increment effect of sample (I) becomes worse. In additional, the results of field test verify the laboratory experiments.

From the above research, we canconclude that the relationship between crude oil composition and ASP flooding is of great significance. As a result, this paper has carried out a lot of related research work and revealed the internal relationship between the two, which has important practical significance to improve the effect of increasing oil and reducing water in ASP flooding technology.
Development of Fluorescence Tagged Scale Inhibitors for Squeeze Applications in Gulf of Mexico
Authors: Liu Ya , Lee Dong , Lu Haiping , Russek Jeffrey
Published: November 2021

Fluorescence tagged (F-tagged) scale inhibitors are drawing more interest in the oil industry and are being applied in the field. One main reason is being easily detectable and differentiable from other scale inhibitors. However, when applied to a new oilfield, it is necessary to evaluate their thermal stability, limit of detection (LOD), and fluorescence measurement interference from other chemicals. Two F-tagged scale inhibitors were tested in this study. They are the same polymeric inhibitors with different and differentiable fluorescent tags. Both F-tagged inhibitors were able to be detected in synthetic brine and field brine from a Gulf of Mexico (GoM) field, with LOD of 1ppm. A coreflood test was also conducted for inhibitor squeeze treatment evaluation. The residual scale inhibitor in core flooding samples was measured by both fluorescence method and high performance liquid chromatography (HPLC). The results from two methods generally match with each other. This strongly indicates that the F-tag is stable on scale inhibitors and fluorescence measurement is a reliable method for scale inhibitor detection. Thermal aging test and long storage test were conducted. For both F-tagged scale inhibitors, the thermal aged samples and samples with different storage lifetime did not show significant difference on scale inhibition performance and fluorescence measurement. The two F-tagged inhibitors tested can tolerate high temperature up to at least 130°C (266°F). With proper storage, F-tagged inhibitors after long shelf storage were still as effective as fresh inhibitors. Based on all the test results in this paper, these two scale inhibitors are ready for squeeze application in GoM.
How Does EOR Polymer Impact Scale Control During ASP Flooding?
Authors: Liu Ya , Vilain Rebecca , Shen Dong
Published: November 2021

Polymer based enhanced oil recovery (EOR) technology has drawn more and more attention in the oil and gas industry. The impacts of EOR polymer on scale formation and control are not well known yet. This research investigated the impacts of EOR polymer on calcite scale formation with and without the presence of scale inhibitors. Seven different types of scale inhibitors were tested, including four different phosphonate inhibitors and three different polymeric inhibitors. Test brines included severe and moderate calcite scaling brines. The severe calcite brine is to simulate alkaline surfactant polymer (ASP) flooding conditions with high pH and high carbonate concentration. The test method used was the 24 hours static bottle test. Visual observation and the residual calcium (Ca2+) concentration determination were conducted after bottle test finished. It was found that EOR polymer can serve as a scale inhibitor in moderate calcite scaling brines, although the required dosage was significantly higher than common scale inhibitors. Strong synergistic effects were observed between EOR polymer and phosphonate scale inhibitors on calcite control, which can significantly reduce scale inhibitor dosage and provides a solution for calcite control in ASP flooding. The impact of EOR polymer on polymeric scale inhibitors varied depending on polymer types. Antagonism was observed between EOR polymer and sulfonated copolymer inhibitor, while there was weak synergism between EOR polymer and acrylic copolymer inhibitors. Therefore, when selecting scale inhibitors for polymer flooding wells in the future, the impact of EOR polymer on scale inhibitor performance should be considered.
Long-term Strategy Optimization of Scale Squeeze Treatment in a Carbonate Reservoir Under CO2-WAG Water-Alternating-Gas Injection
Authors: Azari Vahid , Rodrigues Hydra , Suieshova Alina , Vazquez Oscar , Mackay Eric
Published: November 2021

The objective of this study is to design a series of squeeze treatments for 20 years of production of a Brazilian pre-salt carbonate reservoir analogue, minimizing the cost of scale inhibition strategy. CO2-WAG (Water-Alternating-Gas) injection is implemented in the reservoir to increase oil recovery, but it may also increase the risk of scale deposition.

Dissolution of CaCO3 as a consequence of pH decrease during the CO2 injection may result in a higher risk of calcium carbonate precipitation in the production system. The deposits may occur at any location from production bottom-hole to surface facilities. Squeeze treatment is thought to be the most efficient technique to prevent CaCO3 deposition in this reservoir. Therefore, the optimum WAG design for a quarter 5-spot model, with the maximum Net Present Value (NPV) and CO2 storage volume identified from a reservoir optimization process, was considered as the basis for optimizing the squeeze treatment strategy, and the results were compared with those for a base-case waterflooding scenario. Gradient Descent algorithm was used to identify the optimum squeeze lifetime duration for the total lifecycle. The main objective of squeeze strategy optimization is to identify the frequency and lifetime of treatments, resulting in the lowest possible expenditure to achieve water protection over the well's lifecycle.

The simulation results for the WAG case showed that the scale window elongates over the last 10 years of production after water breakthrough in the production well. Different squeeze target lifetimes, ranging from 0.5 to 6 million bbl of produced water were considered to optimize the lifetime duration. The optimum squeeze lifetime was identified as being 2 million bbl of protected water, which was implemented for the subsequent squeeze treatments. Based on the water production rate and saturation ratio over time, the optimum chemical deployment plan was calculated. The optimization results showed that seven squeeze treatments were needed to protect the production well in the WAG scenario, while ten treatments were necessary in the waterflooding case, due to the higher water rate in the production window.

The novelty of this approach is the ability to optimize a series of squeeze treatment designs for a long-term production period. It adds valuable information at the Front-End Engineering and Design (FEED) stage in a field, where scale control may have a significant impact on the field's economic viability.