bluuebunny/crossref_metadata_2025 huggingface dataset:
Scenario Based Optimization Methodology for Field Development Planning
Authors: Litvak Michael , Rosenzweig Jacob , Marblestone Grant , Matringe Sebastien , Wang Pengju
Published: June 2023

An innovative optimization methodology for field development planning is presented. A new mixed integer optimizer is described. The optimization tool's "user-friendly" plug-in in a commercial reservoir characterization and simulation package is developed, and methodology applications in exploration projects are outlined.

An effective methodology is developed to optimize well placement and facility options in oil fields with multiple reservoirs. The optimized field development plan is selected for individual reservoirs from various well placements, well trajectories, injection strategies, and facility scenarios significantly impacting field oil recovery. Multiple subsurface models representing uncertainties in subsurface descriptions are applied in the optimization process. An effective mixed integer optimizer is developed. The optimizer is based on sequential cycles of a) selection of "promising" scenarios changing one decision variable per simulation and b) evaluations of combinations of the "promising" scenarios using Latin Hypercube sampling.

The optimization workflow is implemented as a user-friendly plug-in to a commercial package, which allows one to a) define locations and trajectories of potential wells, b) define well placement and facility scenarios, c) run optimization workflows, and d) evaluate optimization results.

The developed optimization methodology is successfully applied in several exploration projects. Effectiveness and significant benefits from the optimization applications are demonstrated.

This paper can bring significant benefits to the state of knowledge in the petroleum industry by a) describing the novel methodology for optimizing field development scenarios that have significant impacts on oil recovery, b) applying the new optimizer, c) implementing the optimization plug-in in a commercial package.
An Analytical Method for Estimation of Thermal Fracturing Initiation During CO2 Injection in Depleted Gas Reservoirs
Authors: Huijskes Thijs , de Kok Joop
Published: June 2023

During CO2 injection, cooling and pressure buildup in the near-wellbore may lead to fracturing of the reservoir rock. These fractures affect the injectivity and can have a significant impact on flow assurance. This paper presents the derivation of a quick and simple method to evaluate the onset of thermal fracturing.

This paper starts with geomechanics theory and expressions of minimum horizontal stress in depleted reservoirs. It describes the relations between thermo-poro-elastic stress and the criterion for initiation of (thermal) fracturing. The thermal stress part uses a simplified analytical solution of the stresses around the wellbore taking into account differences due to near-wellbore cooling and far-field virgin temperature conditions. A similar methodology is used to accommodate for pressure difference between the near-wellbore area and the far-field. A set of geomechanical and reservoir parameters are used to set-up diagnostic plots for evaluation. Consequences of the difference between the depletion stress path and injection stress path are discussed. Finally, results are compared to numerical reservoir simulation results.

A proposed thermal stress correction factor, which accounts for differences between a simple analytical solution and a full-field evaluation, is checked and adjusted by comparing analytical and numerical results. First indications show that this geometrical factor and the derived equivalent cold zone radius holds for many cases. The sensitivity of thermal fracturing for several reservoir and rock parameters is discussed. The analytical method found is quick, simple and generates equivalent results to the numerical simulator and is therefore assumed to be accurate for estimation of the moment of fracture initiation.

The resulting diagnostic plots present a quick and simple alternative to geomechanical simulation for evaluating the possibility and moment of fracture initiation. This method can help in early-stage feasibility work and determine if more detailed modelling is needed.
Applying Machine Learning to Minimize Wireline Formation Testing Failures in Thin Laminated Sands
Authors: Fayzullin Maksim , Schmidt Dennis , Deckers Marie
Published: June 2023

This paper demonstrates how supervised machine learning (ML) aids planning and acquisition of wireline formation testing (WFT) in thin laminated sands. Available well data was used to train a set of algorithms to identify intervals where tests are likely to fail. The trained model aims to prevent WFT failures what in turn results in reduced rig downtime, increased efficiency of the logging contracts and improved reservoir characterization.

Wireline formation testing is essential to acquire rock and fluid characteristics in multilayered reservoirs setting up the base for the upcoming decisions. This becomes significantly complicated in thin laminated sands with a thick hydrocarbon column, requiring hundred(s) of points to meet given objectives. The percentage of failed tests can be much higher than those of being successful. In this context an automated advisory system, based on the abundant historic WFT dataset, can mitigate personal biases of the subsurface team and boost the share of successful tests in future wells.

A combined set of wireline logs served as features to predict WFT outcome in two classification approaches. Binary classification predicts likelihood of having a good test or a failure, whereas multi-classification further details failure types into 5 categories. The overall dataset comprised more than 500 points (testing attempts) within the concession to train various ML models, using variety of preprocessing and hyper parameters. Their accuracy and area under curve (AUC) were used as the ranking criteria. The performance mostly depends on the number of classes to be predicted, the number of input features and the number of data points available for training. Less classes to predict and more input features result generally in better model metrics. The final selected model attained a maximum accuracy of 0.75 in two exploration wells in the adjacent concessions, i.e. correctly predicting 75 outcomes out of 100 wireline formation tests. A log interpretation suite accesses the deployed model via a cloud endpoint for the upcoming infill wells.

The approach could improve wireline formation testing in other reservoirs or regions prone to WFT failures, where accumulated data is sufficient for machine learning applications. This could result in tangible savings during well operations.
Modified Cam-Clay Model Parameters for Well-Cement
Authors: Soustelle Vincent , Moghadam Al , Corina Anisa Noor
Published: June 2023

Geothermal heat is expected to become an important sustainable energy source for the Netherlands. Geothermal wells are expected to last for decades and provide an acceptable return on investment. The well cement in geothermal wells experiences a unique stress condition due to the injection/production of cold/hot water in a doublet. The impact of these cyclical loads on cement has yet to be discovered. Critical state constitutive models such as the Modified cam-clay (MCC) are most suitable to describe cement's mechanical behavior. In this work, we present a new experimental protocol to measure the MCC model parameters for well-cement and to quantify the plastic damage accumulation under realistic cyclical conditions relevant to the Dutch geothermal wells. The protocol was tested on class G cement.

The experiments were carried out in a triaxial apparatus and consisted of (1) unconfined compressive strength (UCS) tests; (2) hydrostatic compression tests to find the initial size of the yield surface (p0) and the slope of the swelling and compression lines (κ and λ); (3) triaxial tests on both the dry and wet side of the yield surface; and finally (4) cyclic loading tests under conditions relevant to a mid-enthalpy doublet. The effect of cyclic loading on cement integrity is quantified by measuring the inelastic deformation and elastic moduli after each cycle, followed by a triaxial test.

The UCS tests on class G cement show peak stresses of 34-41 MPa, and critical state stresses (CSS) of approximately 10 MPa. The triaxial tests performed on the dry and wet sides display a strain softening and hardening behavior, respectively, as predicted by the MCC model. CSS values from all the tests align along the newly defined critical state line (CSL) for class-G cement. The CSL has a slope M = 1.5 and an intercept (p) of −3.7 MPa, close to the anticipated tensile strength of class-G cement. Hydrostatic tests give p0 of 23-29 MPa and κ and λ of 0.0046 and 0.02. The cyclic test simulating the producer well shows negligible plastic deformation after 10 cycles. Conversely, the deep injector well shows cement damage accumulation.
Geothermal Reservoir Optimization Empowered by a Generalized Thermal Decline Model and Deep Learning
Authors: Yan Bicheng , Gudala Manojkumar , Sun Shuyu
Published: June 2023

Geothermal energy is naturally renewable harnessed from subsurface reservoirs and is feasible to help enrich the energy spectrum and decarbonize the economy. Cold geo-fluid such as water is injected to extract the heat from hot rocks, and then hot fluid can be produced, which can be used for the purpose of heating or power generation. The reservoir management of geothermal recovery process is an integration of geology, drilling, reservoir and production, and particularly it requires expensive simulations that couple the thermo-hydro-mechanical (THM) effect. In this study, we developed a reservoir simulation model to simulate the enhanced geothermal systems (EGS). After evaluating the produced fluid temperature curves, we proposed a generalized thermal decline model that considers the thermal breakthrough and the following decline behavior. This model is parsimonious with only 3 variables. Moreover, a forward surrogate model by deep neural network is developed to predict the decline model variables and the ultimate total net power based on the reservoir parameters. The forward surrogate is integrated with a differential evolution optimizer, which considers reservoir uncertainties and nonlinear constraints for the optimization of the total net power. Accelerated by the thermal decline model and forward surrogate model, we were able to efficiently perform reservoir optimization in high-performance computing environment, and this makes the workflow quite scalable for real-time reservoir management.
Numerical Investigation of Subsurface Hydrogen Storage: Impact of Cyclic Injection
Authors: Zhang Haiyang , Al Kobaisi Mohammed , Arif Muhammad
Published: June 2023

The use of hydrogen (H2) as a clean fuel has gained enormous interest in recent years. For this purpose, excess H2 can be stored in subsurface geological formations. The underground hydrogen storage (UHS) can help to mitigate the challenges associated with seasonal variability in renewable energy production and provide a reliable source of hydrogen for future utilization. While recent studies showed that repeated hydrogen injection and production in aquifer can result in hydrogen and water cyclic hysteresis, the existing classical trapping models fail to model such phenomena in the context of hydrogen and brine. Moreover, the impact of cyclic hysteretic behavior effect received little or no attention on the reservoir scale and thus still remains poorly understood. This study conducts numerical simulations to analyze the impact of cyclic hysteresis on the efficiency of underground hydrogen storage. The results showed that the cyclic hysteresis effect will result in a shorter lateral migration of the injected H2 and more H2 accumulating in the vicinity of the wellbore due to the poorer hydrogen flow ability and higher critical hydrogen saturation. The accumulated hydrogen will in turn contribute to a higher hydrogen recovery factor and thus improve the efficiency of underground hydrogen storage.
Chasing Gas Asset Value Maximization: An Integrated Workflow Led by Reservoir Monitoring
Authors: Mariotti Pamela , Toscano Claudio , Vecera Carmela , Da Marinis Annunziata , Frau Simone , Poggio Franco , Pangestu Imam , Praja Kurna
Published: June 2023

Currently the oil and gas industry is becoming more digitalized. The abundance of data varieties that are recorded has driven the industry to move forward from the conventional data management to more fashioned data acquisition. The field under study (Field A) is a deep-water gas asset, characterized by a complex internal architecture of many separate and discrete gas charged stacked sand bodies. Objective of this paper is to show the key role of the reservoir monitoring strategy, fully integrated in a multidisciplinary workflow that allowed to detail the reservoir conceptual model leading to the identification of valuable production optimization opportunities.

Field A produces through smart wells with selective completions, equipped with permanent down hole gauge (one for each open layer) allowing Real Time Monitoring of the key dynamic parameters (e.g., rate, flowing bottom hole pressure) and implementation of surveillance actions such as selective Pressure Transient Analysis. A workflow is implemented to be able to describe each open layer performance integrating all available data starting from well back allocation verification through virtual metering implementation. Then, Inflow Performance Relationship per layer is used to back-allocate well production to each unit. Robust continuous update of material balance analysis for each layer allowed to verify alignment between the geological gas volume in place and the dynamic connected volume, leading to update coherently also the dynamic model.

Comparison between geological gas volume in place and dynamic connected one triggered a revision of geological modelling, reviewing seismic uncertainty and facies modelling, trying to embed dynamic evidence. Among parameters taken in account, layers internal connectivity resulted as the most impacting one. The revised model allowed to identify and rank residual opportunities on developed layers and possible additional explorative targets. The result of this screening led to the strategic business decision to plan an infilling well, with primary target the best unexploited sub-portion identified inside one of the analyzed layers together with other stacked minor targets. The expectation of primary target resulted confirmed by the data acquired in the new well drilled.

Moreover, the real time monitoring workflow has been implemented in a digital environment for continuous automated update resulting in continuous reservoir monitoring and management.

The successful experience on Field A proved the key role of a structured Reservoir Monitoring strategy as "drive mechanism" for a decision-making process extremely impacting on the core business. The automation of data extraction, will lead the way to an increasingly efficient use of "big amount" of data coming from real time monitoring, thus further improving the overall process of asset maximization opportunities identification.
Rapid Time-Lapse Monitoring of Geological Carbon Storage
Authors: Gonzalez Keyla , Misra Siddharth
Published: June 2023

Precision monitoring of the subsurface carbon-dioxide plume ensures long-term, sustainable geological carbon storage at a large scale. Electrical resistivity tomography (ERT) can accurately map the evolution of the CO2 saturation during geological carbon storage. To better monitor the CO2 plume migration in a storage reservoir, we develop an unsupervised spatiotemporal clustering to process the CO2 saturation maps derived from the ERT measurements acquired over 80 days. Using dynamic time wrapping (DTW) Kmeans clustering, four distinct clusters were identified in the CO2-storage reservoir. The four clusters exhibit Davies-Bouldin (DB) index of 0.71, Calinski-Harabasz (CH) index of 262791, and DTW-silhouette score of 0.58. Unlike traditional clustering methods, the DTW K-means incorporates a temporal distance metric. Compared to DTW KMeans, traditional clustering methods, such as agglomerative and meanshift clustering, exhibit a lower performance with DB index of 0.95 and 1.01, respectively, and CH index of 131593 and 69438, respectively. Statistical analysis indicates that contrast stretching and fast-Fourier transform are strong geophysical signatures of the spatiotemporal evolution of CO2 plume. We also identified a strong correlation between injection flow rate and the spatial evolution of high CO2 content. A tensor-based feature extraction was critical for capturing both the temporal and spatial components relevant to the evolution of CO2 plume in storage reservoir.
Maintaining the Integrity of Geothermal Wells During the Construction Process
Authors: Al Fakih Abdulqawi , Natasya Sarah , Balamir Ozgur , Sebbane Slimane , Dhanto Michael Ari
Published: June 2023

Geothermal well construction activity has been accelerating considerably to assist in meeting the zero carbon emissions goal of many countries and industries by 2050. In some areas, the geothermal well construction methods are inherited from oil and gas wells, and the construction activity is carried out using the same equipment and similar processes and guidelines. This is particularly visible when it comes to well-control management. However, as more and more oilfield professionals enter the geothermal arena, it becomes essential to understand the differences between oil and gas and geothermal wells that heavily impact the construction of the geothermal well. There is an emerging need to differentiate between the oil and gas and geothermal well control and well integrity criteria required to drill conventional geothermal wells. Considering the broad range of geothermal well types and their associated flow conditions, the authors limited the discussion to conventional geothermal wells and, more specifically, to the geothermal wells drilled in volcanic fields.

Common failures pertaining to well control that were recorded throughout the history of geothermal well drilling (starting circa the 1920s) revolve around the handling of thermal (steam) kicks. After careful investigation, the root causes of most of the steam kicks were found to be (i) engineering and crew incompetence and lack of specific experience, (ii) lack of targeted risk assessment, and (iii) lack of clear standard work instructions to be followed during routine drilling and well control operations. A clear need was then identified for a specific well control procedure and detailed drilling plan enhancements, which would also address the differences between well control operations during drilling hydrocarbon and geothermal wells.

This paper lays out the basics of the preferred approach to maintain the geothermal well integrity by well control during its well construction process, intended to reduce risk and improve performance. It will also illustrate the main differences between geothermal and hydrocarbon well control during the well construction phase.
Potential Evaluation on the Artificial Geothermal Energy of Post Steamed Heavy Oil Reservoirs
Authors: Dong Xiaohu , Zhang Hao , Lu Ning , Xiao Zhan , Lyu Xiaocong , Liu Huiqing , Chen Zhangxin
Published: June 2023

Steam injection process is usually the primary extraction method for heavy oil reservoirs. But, in recent decades, with the steam injection operation continues, most of the steamed heavy oil reservoirs have achieved a depleted status (residual oil zone). Meanwhile, for most post steamed heavy oil reservoirs, the average formation temperature can reach above 150℃. It indicates that they can be considered as a potential artificial geothermal energy source. In this work, those post steamed heavy oil reservoirs are proposed as a source of artificial geothermal energy, and the extraction potential is evaluated.

A heavy oil reservoir simulation model is firstly constructed based on a geological model which involves a five-spot well pattern of steam flooding operation in Shengli oilfield, Sinopec. This model can be used to represent a depleted status of a steamed heavy oil reservoir. Subsequently, based on this five-spot well pattern of steam flooding, a geothermal heat extraction model is developed. In order to accurately evaluate the extraction potential of this artificial geothermal energy, the wellbore heat loss is also considered by using a discretized wellbore model. Thus, two different extraction methods of water injection and CO2 injection are simulated. Then, based on the simulation model, the factors that control the heat extraction rate in high temperature depleted heavy oil reservoirs are also discussed. Results show that a post steamed heavy oil reservoir can be a potential source of geothermal energy. By using the existing steam flooding well pattern, the initial investment is reduced, thus, a high-efficient development can be achieved. From the simulation results, it is found that the method of geothermal energy extraction in high temperature depleted heavy oil reservoir (165 ℃, 2 MPa) using CO2 can achieve a high-speed geothermal energy extraction process in the early stage (<1.5 years). In comparison, a method of water injection process performs better within a longer time period (>1.5 years). Simultaneously, it is found that the bottom-hole pressure, heat extraction time and CO2 injection rate can have the biggest impact on the heat extraction rate.

Because of the high temperature condition, the post steamed heavy oil reservoirs can have a huge potential of heat mining. The technology of geothermal energy extraction can further enhance their development value and prolong the working life.
Numerical Models for Upscaling of Caprock Properties from Small Sample Laboratory Testing
Authors: Cerasi Pierre Rolf , Ringstad Cathrine , Skorpa Ragnhild
Published: June 2023

This work had as objective to provide simple numerical models capable of bridging between small sample or cuttings mechanical tests in the laboratory and reservoir-scale models. Numerical models are developed for tests such as the Brazilian indirect tensile test and the direct shear punch test. Intermediately upscaled shale models can be developed to model shale caprock behavior under subsurface storage operations such as CO2 or H2 storage. Of importance to creating a useful material model is to take into account the anisotropic nature of shale caprock, by introducing parallel weak planes in the models. Simulating laboratory tests allows one to tune spacing and properties of such planes with no need for microscopic and detailed accuracy. The effect of weak plane spacing and orientation on the elastic deformation of a layered material is investigated using a simple finite difference scheme. In uniaxial deformation, weakening or hardening is included through a stress-dependent stiffness modulus. Strength dependence on weak plane orientation is modelled using the finite element code DIANA. Tuning of weak plane frequency and stiffness contrast to rock bulk results in stress strain plots where the upscaled stiffness corresponds to simple analytical models. This makes it possible to specify anisotropy parameter inputs for large-scale models. Further tuning to laboratory experiments is possible through the use of the stress-dependent stiffness, making more accurate predictive upscaled models. Similarly, results from tensile strength and shear strength numerical testing highlight the fractures and their interaction with weak planes.
Visualization of Surfactant Flooding in Tight Reservoir Using Microfluidics
Authors: Scerbacova Alexandra , Pereponov Dmitrii , Tarkhov Michael , Kazaku Vitaly , Rykov Alexander , Filippov Ivan , Zenova Elena , Krutko Vladislav , Cheremisin Alexey , Shilov Evgeny
Published: June 2023

Surfactant flooding is among the most studied and widespread EOR technologies that is being introduced into tight and low-permeable reservoirs to mobilize trapped oil. Typically, the selection of formulations for chemical flooding is associated with numerous challenges and constraints such as time-consuming core flooding tests, the high cost of the tests with modern saturation control methods, and a limited amount of core samples. To overcome these issues, microfluidic technology was applied to optimize the screening of surfactant compositions for flooding. The workflow of this project consisted of five main steps: (1) fabrication of microfluidic chips, (2) surfactant screening in bulk, (3) surfactant flooding in microfluidic chips, (4) image analysis and data interpretation.

Silicon-glass microfluidic chips, which are 2D representatives of the reservoir porous media, were used in the experiments. The porous structure geometry was developed based on CT images of core samples from a particular field with low permeability. For the selected surfactants, interfacial behavior on the boundary with n-decane was studied and correlated with hydrocarbon recovery ability. The results obtained revealed that the IFT patterns have a significant influence on displacement efficiency. Thus, the surfactant compositions with a lower initial IFT than the equilibrium value achieved higher recovery factors.
The Race to Conquer the Hydrogen Business: The Seven Territories of Australia's Strategy
Authors: Trujillo Maria Isabel , Veen Paulien , Szemat-Vielma Waldemar , Escobar-Burnham Esther
Published: June 2023

Australia has embarked on a fast race to become the leading hydrogen provider in the Asia Pacific, supported by countries such as Japan and South Korea as firm customers. The seven territories of Australia are developing their business strategies to achieve competitiveness and a place in the race.

A strategy based on a strengths, weakness, opportunities, and threats (SWOT) analysis has been derived from each territory, considering the current state-of-the-art hydrogen technologies and their main drivers. These strategies have been benchmarked against the Australia Council National Hydrogen Strategy and the Australia Electricity Market Operator Strategy regarding the scenario of a hydrogen superpower for Australia to become an essential player in the hydrogen market using the IBA (Interactive Bundle Analysis) framework.

The seven territories’ strategies were analyzed, and a set of recommendations are derived from this analysis with the aim to reinforce each territory strategy, providing the Australian Federal Government a framework to assess which project to finance projects first and assist in de-risking them to attract private capital, which is essential for the country to become a large-scale hydrogen producer and exporter.

This analysis recommends that should Australia focus on the development of blue hydrogen first and secures market share via Western Australia using steam methane reformer (SMR) and Victoria with the brown coal gasification, both fitted with the corresponding carbon capture and storage (CCS). In parallel, the Australian Federal government should incentivize Tasmania to produce green hydrogen followed by Queensland and Western Australia while other territories need to develop as per their individual strengths.
Discussion on the Wettability Alteration Behavior Induced by CO2-Brine-Silica Interaction and Its Effect on the Performance of Hybrid Steam-CO2 Flooding
Authors: Li Yu , Liu Huiqing , Luo Chen , Dong Xiaohu , Wang Qing , Liu Chuan , Wang Zhipeng
Published: June 2023

Hybrid steam-CO2 flooding, mature technology to enhance oil recovery, promotes the deposition of asphaltene from heavy oil and the CO2-brine-silica interaction to change the wettability of silica surface. The asphaltene deposition can promote lipophilicity of the silica surface while the CO2-brine-silica interaction can enhance its hydrophilicity. Therefore, aiming to study the wettability alteration during hybrid steam-CO2 flooding, we explore the interaction characteristics of CO2 with oil and brine on the silica surface.

In this work, a series of experiments are conducted to reveal the wettability alteration of silica by the interaction of CO2 with different fluids under different conditions. The CO2-brine-silica interaction experiments and the CO2-oil-silica experiments are carried out in the temperature and pressure-resistant vessel to comprehensively acquire the silica under the influence of various fluids in the static process. In addition, based on the core flooding experiments, computerized tomography (CT) technology is applied to realistically and automatically extract the dynamic contact angle in the dynamic process.

The result of contact angle from CO2-brine-silica interaction experiments shows the interaction between CO2 and brine evidently enhances the hydrophilicity of the silica surface under high temperature, and the ability of CO2 and brine to promote the increase of hydrophilicity is much greater than that in the absence of CO2. Moreover, the result of contact angle from CO2-oil-silica experiments indicates the increase of temperature and CO2 pressure makes the silica surface covered by heavy oil present the tendency of hydrophobia. The micro-CT images from core displacement experiments are automatically processed by an intelligent algorithm to extract the remaining oil distribution and display the data of dynamic contact angle. Under the influence of steam, the remaining oil mainly performs the form of membrane oil attached to the silica surface. Furthermore, the edges of the remaining oil take on an irregular shape and the contact angle reflecting hydrophobicity reach 45.2% after steam flooding. After the stage of CO2 flooding, the obvious reduction in membrane oil thickness occurs and the number of contact angles reflecting hydrophobicity decreases to 35.3%. Moreover, the oil film gradually transforms into many oil droplets on the surface under the steam and CO2, which may be conducive to the migration of heavy oil in a porous medium.

Taking static and dynamic characteristics of contact angle into account under different environments, the conditions and mechanism of wettability alteration can serve as a perspective for CO2 application in pore-scale displacement.
Utilization of Microfluidics Technology for an Efficient Polymer Screening Process in Enhanced Oil Recovery (EOR) Applications
Authors: Al Ismaili Safa , Gaol Calvin , Langanke Nils , Ganzer Leonhard
Published: June 2023

This work introduces an efficient approach in addition to the traditional scheme of polymer screening for the application of enhanced oil recovery. Microfluidics technology which requires less sample volumes, and less time consumption, is applied to the polymer screening procedure. This approach delivers an efficient screening process and enables the upscaling of polymer flow behavior in porous media.

This work investigates three commercial polymer products, A, B, and C, which vary in average molecular weight at shear rate (0.1 – 1000 s−1) and temperature (20°C– 60°C). Fifteen polymer solutions with different concentrations are made from the three products and screened through three evaluation stages. The first stage is measuring the bulk shear viscosity of the polymer solutions in the rheometer. The second stage is conducting single-phase polymer flooding through a novel micromodel. The stage of this approach applies the results from the earlier stages by running two-phase flooding experiments that implement polymer flooding for reservoir conditions of an oil field in Oman. The micromodel structure used in this work is generated based on X-ray micro-computed tomography (μCT) images of a Bentheimer core plug. Thus, the micromodel's porosity, permeability, pore, and grain size distribution are similar to the core plug. This characteristic gives an upscaling potential to a larger scale, such as core plug or even a field implementation.

A database with bulk shear viscosity and model fits (Power law & Carreau) is generated from the rheometer measurements for polymers A, B, and C. A novel 3D surface model that relates the shear rate, temperature, bulk viscosity, and concentration is developed from the data in the first stage. The single-phase flooding experiments allow the investigation of the behavior of polymer in porous media under shear and extensional flow. Furthermore, the comparison of bulk shear viscosity and in-situ viscosity shows the potential to support the analysis of an empirical constant (C-factor). In addition, polymer injectivity and retention are investigated by analyzing the pressure drop and residual resistance factor after each single-phase polymer flooding experiment. The last stage of this work provides the improvement of displacement efficiency and the recovery factor, which measures the success of the approach.

The novelty of this approach is the utilization of the linear Bentheimer micromodel for delivering an efficient polymer screening process. This micromodel reflects similar rock properties as Bentheimer rocks, which provide the potential to upscale the results from microfluidics to reservoir rocks. In addition, the novel 3D surface model developed in this work allows comprehensive screening, which is accomplished through combining the parameters required in polymer evaluation at one domain.
Red biases sex categorization of human bodies
Authors: Chen Na , Nakamura Koyo , Watanabe Katsumi
Published: June 2023

Color is associated with gender information (e.g., red-female). This study aimed to investigate whether the color red could influence the categorization of human bodies by sex. Visual stimuli were created using body silhouettes with varying along the waist-to-hip ratio from female to male perceptions. These stimuli were presented in conjunction with red, green, and gray colors, which were used either as body color (Experiment 1) or background color (Experiment 2). Participants were instructed to categorize the sex of the body stimuli as either male or female by pressing labelled keys. The results revealed that the color red had distinct effects on body perception, contingent on its role as a body color or background color. Specifically, when used as a body color, red induced a feminine body perception, whereas as a background color, it leaned towards a perception of masculinity. These findings highlight the significance of color cues in shaping gender-related body bias.
An explication of the 800-day COVID-19 pandemic spread behaviour of seven countries from different continents and the world total in a non-linear time series framework
Authors: KAVAL Mesut , TATLIPINAR Hasan
Published: June 2023

The time series consisting of 800-day COVID-19 spread data from USA, Germany, Brazil, India, Japan, Egypt, Turkey, and world total taken from the Our World in Data database, was analysed within the framework of non-linear time series. Correlogram diagrams, Fourier power spectra and Lyapunov exponents were examined for each series and it was seen that they did not behave linearly. For these non-linear time series, the lag time and embedded dimension were calculated and 3-dimensional phase spaces for each case were constructed. By examining the constructed phase space profiles, the spread dynamics of COVID-19 in each country and the world total is discussed comparatively. As a result of the phase space analysis, it was seen that the spread of COVID-19 was complex and three different complex behaviour patterns emerged according to the examined countries. This behavioral decomposition was also seen in the correlogram diagrams of the countries, the Fourier power spectrum and the Lyapunov exponents. The nonlinear time series method we used will contribute to the understanding of the qualitative characteristics of the complex behaviour of the COVID-19 pandemic.
Stabilizing negative charge in organic molecules for high-efficiency, long-lifetime delayed electroluminescence
Authors: Huang Tianyu , Wang Qi , Zhang Hai , Xin Yangyang , Li Guomeng , Zhang Yuewei , Zhang Dongdong , Duan Lian
Published: June 2023

The internal quantum efficiencies of organic light-emitting diodes (OLEDs) with thermally activated delayed fluorescence (TADF) have reached 100%. However, the combination of a high efficiency and a long operational lifetime is still a major conundrum of commercialization. Here, we develop TADF emitters with auxiliary acceptors to stabilize negative charge by delocalizing electron distribution, not only strengthening the intrinsic molecular stability in both excited and anionic states, but also leading to faster exciton consumption by balancing triplet-up-conversion and singlet-radiation. The targeted compounds as emitters in OLEDs exhibited high maximum external quantum efficiencies of 27.9-37.1% and remarkably long LT95s (times to 95% of the initial luminance) of 446 and 628 h for blue and greenish-blue devices at 1,000 cd m-2, which can be further extended to 451 and 2,491 h by using them as sensitizers for blue and green multi-resonance (MR) emitters with y color coordinates of 0.27 and 0.71, respectively.
Electrodialysis: as a potential technology for 4-nitrophenol abatement from wastewater
Authors: Lopez Manuel , Cornaglia Laura María , Gutierrez Laura Beatriz , Bosko María Laura
Published: June 2023

4-Nitrophenol is a widely used emerging pollutant in various industries, including the production of agrochemicals, drugs, and synthetic dyes. Due to its potential environmental harmful effects, there is a need to study its reuse and removal from wastewater. In this study, electrodialysis technology was used to separate 4-Nitrophenol ions using a four-compartment stack. The effects of supporting electrolyte concentration, pH, voltages, and current density on the performance of electrodialysis for separating 4-nitrophenol were investigated. A high extraction percentage of 77% was achieved with low energy consumption (107 kwh kg− 1) when high 4-nitrophenol flows and transport numbers were reached.
The Association of Marital Status with Kidney Cancer Surgery Morbidity - A Retrospective Cohort Study
Authors: Tang Yuzhe , Valovska Marie-Thérèse , Nolazco José , Yim Kendrick , Chung Benjamin , Chang Steven
Published: June 2023

Purpose:
To better understand whether the marital status impacts 90-day postoperative outcomes following kidney cancer surgery.
Methods:
We performed a retrospective cohort study of adult patients undergoing elective partial or radical nephrectomy to manage kidney masses from 2003 to 2017 using the Premier Hospital Database, a national hospital discharge dataset. Multinomial logistic regression models controlling for a wide range of clinicodemographic, surgical, and hospital characteristics were used to assess an association between marital status and postoperative complications. The primary outcome was 90-day complications, including minor complications (Clavien grades 1-2), non-fatal major complications (Clavien grades 3-4), and mortality (Clavien grade 5). Secondary outcomes included patient disposition and readmission rates.
Results:
The study cohort comprised 106,752 patients, of which 61,188 (57.32%) were married. The overall incidence of minor complications, major complications, and death was 24.04%, 6.00%, and 0.71%, respectively. Marriage was associated with a significantly lower incidence of minor (OR 0.97; 95% CI: 0.94-0.99) complications following open or radical nephrectomy and major complications (OR 0.89; 95% CI: 0.84-0.95) for all surgical types and approaches (Figure 1). There was no association between marital status and mortality (OR 0.94; 95% CI: 0.81-1.10).
Conclusions:
Marriage is associated with a significant reduction in major complications following kidney cancer surgery, likely because it is associated with greater social support, which is beneficial in the postoperative phase of care. Marital status and social support may play a role in the preoperative decision-making process and counseling for patients considering kidney cancer surgery.
Assessment of river recreation safety using spatial river recreational index by integration of hydrodynamic model and fuzzy logic
Authors: Kwon Siyoon , Seo Il Won , Kim Byunguk , Jung Sung Hyun , Kim Yong Do
Published: June 2023

As the demand for recreational activities in rivers has increased, the assessment of the existing safety measures of these activities has become crucial to prevent accidents. Current safety measures have mainly focused on water quality factors, while the safety of in-water activities is also influenced by river hydraulic conditions. Hence, we proposed a spatial river recreational index (SRRI) that considers hydraulic parameters to evaluate the safety of recreational activities in rivers. Using a 3D hydrodynamic model, we reproduced the spatial distribution of hydraulic parameters under various discharge conditions to estimate the SRRI based on fuzzy logic. The application of the SRRI at the confluence of the Nakdong-Guemho River in South Korea revealed that each hydraulic parameter contributed differently to the safety according to discharge and morphological conditions. For instance, flow direction decreased safety in the near-field of the river confluence, while water depth played a significant role in the meandering reach of the Nakdong River. Flow velocity was the most critical factor for nonpowered activities, such as sailing and paddling/wading, under high-flow conditions. Sailing was found to be unsafe in the main flow zone and near-field of the river confluence due to its sensitivity to discharge change. In contrast, paddling/wading and leisure boats were less sensitive to discharge changes and could be partly allowed under high-flow conditions, except in the deep-water zone in the meandering reach. Therefore, SRRI is expected to help many users with safe recreational activities in rivers by providing spatial safety information based on various hydraulic conditions.
Influence of Changes in OM Content and Form on the Adsorption of Two Typical Antibiotics to SPM
Authors: Shen Zihao , Sun Yali , Yang Ye , Zheng Xiaolan , Shang Jingge , Liu Yanhua , Guo Ruixin , Chen Jianqiu , Liao Qianjiahua
Published: June 2023

Antibiotics are commonly detected in natural waters. Suspended particulate matter (SPM) in surface water has a good adsorption capacity for antibiotics, and the organic matter (OM) in SPM is the key factor for this adsorption. We investigated the contribution of OM content and form to the adsorption of tetracycline (TC) and norfloxacin (NOR) in the SPM of Taihu Lake. To change the content and form of OM in SPM, we burned it at 505 ℃ and oxidised it with H2O2, respectively. The OM in the sample that was combusted (expressed as SPM-505 ℃) was almost entirely eliminated, and the adsorption amount of TC decreased by 14.8% when compared to the original sample, while the adsorption amount of NOR decreased by 64.8%, indicating that OM content contributes to the adsorption of antibiotics. Although the OM content in the oxidised sample (expressed as SPM-H2O2) decreased, the adsorption amounts of TC and NOR increased by 31.7% and 2.8%, respectively, compared with the original sample. The infrared spectrum and elemental analysis results showed that the morphology of the OM changed, suggesting that the structure of the OM contributes substantially to the adsorption of antibiotics. The contribution of OM to NOR adsorption was greater than that of TC. In conclusion, the results verify the importance of OM in adsorbing antibiotics onto SPM, which may provide basic data for antibiotic migration in surface water.
Smart metering and communication interventions reduce significant water leakage by faulty toilets in purpose-built student accommodation
Authors: Zang Jian , Kumar Manish , Werner David
Published: June 2023

Water efficiency is a global sustainability challenge encapsulated in the United Nation’s Sustainable Development Goal 6 (SDG6), target 6.4. We used building level smart metering to investigate low endpoint water use efficiency in purpose-built student accommodation blocks, a rapidly growing residence type in the United Kingdom. Baseflow accounted for up to 42% of the annual water demand in three accommodation blocks housing 240 students at Newcastle University. Audits identified faulty, continuously running toilets as the main reason for these high baseflows. Each faulty toilet wasted between 4,800 to 12,000 litres per day of potable water, equivalent to the baseflow corrected water use of between 47 and 106 students. The median payback period for recovering the cost of toilet repairs via reduced water bills was 2.9 days, less than the median 6-day period of water wastage before a faulty toilet was identified and repaired. Management, maintenance and cleaning staff, and student occupant engagements reduced baseflows in Windsor Terrace from 4,577 cubic meters in the calendar year 2017 to 2,453 cubic meters in the calendar year 2019. These water savings amounted to an annual water bill saving of £4,023, five times higher than the £828 annual smart metering costs. We conclude that rapid identification and repair of faulty appliances supported by smart metering is a cost effective and sustainable water efficiency strategy. With timely repairs of faulty appliances, significant water savings can be achieved without up-front investment into additional infrastructures such as water storage tanks and pipes, which have embedded environmental impacts.
Biochar-layered double hydroxide composites for the adsorption of tetracycline from water. Synthesis, Process Modeling and Mechanism
Authors: Zubair Mukarram , Manzar Mohammad Saood , El-Qanni Amjad , Haroon Hajira , Alqahtani Hissah A. , Al-Ejji Maryam , Mu’azu Nuhu Dalhat , AlGhamdi Jwaher M. , Haladu Shamsuddeen A. , Al-Hashim Dana , Ahmed Syed Z.
Published: June 2023

In this study, the MgFeCa layered double hydroxides was supported in biochar (B) using co-precipitation, hydrothermal, and co-pyrolysis methods. The prepared B-MgFeCa composites were investigated for tetracycline (TC) adsorption from an aqueous solution. The B-MgFeCa composites synthesized through co-precipitation and hydrothermal methods exhibited better crystallinity, functional groups, and well-developed LDH structure within the biochar matrix. However, the co-pyrolysis method resulted in the LDH structure breakage, leading to the low crystalline composite material. The maximum adsorption of TC onto all B-MgFeCa was obtained at an acidic pH range (4-5). The B-MgFeCa composites produced via hydrothermal and co-pyrolysis methods showed higher and faster TC adsorption than the co-precipitation method. The kinetic results can be better described by Langmuir kinetic and mixed order models at low and high TC concentrations, indicating that the rate-limiting step is mainly associated with active binding sites adsorption. The Sip and Freundlich models showed better fitting with the equilibrium data. The TC removal by B-MgFeCa composites prepared via hydrothermal and co-pyrolysis was mainly dominated by physical and chemical interactions. The composite obtained via the co-precipitation method adsorbed TC through chemical bonding between surface functional groups with anionic species of TC molecule. The B-MgFeCa composite showed excellent reusability performance for upto five cycles with only 30% decrease in TC removal efficiency. The results demonstrated that B-MgFeCa composites could be used as promsing sorbent material for effective wastewater treatment.