bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyzing problem framing in design teams: a systems mapping approach
Authors: Litster Gregory , Cardoso Carlos , Hurst Ada
Published: November 2024

Early phases of the design process require designers to select into view elements of the problem that they deem important. This exploration process is commonly referred to as problem framing and is essential to solution generation. There have recently been calls in the literature for more precise representations of framing activity and how individual designers come to negotiate shared frames in team settings. This paper presents a novel research approach to understand design framing activity using a system thinking lens. Systems thinking is the way that we understand a system’s components and the interrelations to create interventions, which can be used to move the system outcomes in a more favorable direction. The proposed approach is based on the observation that systems as mental representations of the problem bear some similarity to frames as collections of concepts implicit in the designer’s cognition. Systems mapping – a common visualization tool used to facilitate systems thinking – could then be used to model external representations of framing, made explicit through speech, and sketches. We thus adapt systems mapping to develop a coding scheme to analyze verbal protocols of design activity to retrospectively represent framing activity. The coding scheme is applied on two distinct datasets. The resulting system maps are analyzed to highlight team problem frames, individual contributions, and how the framing activity evolves over time. This approach is well suited to visualize the framing activity that occurs in open-ended problem contexts, where designers are more focused on problem finding and analysis rather than concept generation and detailed design. Several future research avenues for which this approach could be used or extended, including using new computational methods, are presented.
Oro-faecal transmission of SARS-CoV-2: A systematic review of studies employing viral culture from gastrointestinal and other potential oro-faecal sources and evidence for transmission to humans
Authors: Gandini Sara , Conly John , Spencer Elizabeth A. , Evans David , Rosca Elena C , Brassey Jon , Maltoni Susanna , Onakpoya Igho , Plüddemann Annette , Jefferson Tom , Heneghan Carl
Published: November 2024

The extent to which the oro-faecal route contributes to the transmission of SARS-CoV-2 is not established.

We systematically reviewed the evidence on the presence of infectious SARS-CoV-2 in faeces and other gastrointestinal sources by examining studies that used viral culture to investigate the presence of replication-competent virus in these samples. We conducted searches in the WHO COVID-19 Database, LitCovid, medRxiv, and Google Scholar for SARS-CoV-2 using keywords and associated synonyms, with a search date up to 28 November 2023.

We included 13 studies involving 229 COVID-19 subjects – providing 308 faecal or rectal swab SARS-CoV2 reverse transcription-polymerase chain reaction (RT-PCR)-positive samples tested with viral culture. The methods used for viral culture across the studies were heterogeneous. Three studies (two cohorts and one case series) reported observing replication-competent SARS-CoV-2 confirmed by quantitative RT-PCR (qPCR) and whole-genome sequencing, and qPCR including appropriate cycle threshold changes. Overall, six (1.9%) of 308 faecal samples subjected to cell culture showed replication-competent virus. One study found replication-competent samples from one immunocompromised patient. No studies were identified demonstrating direct evidence of oro-faecal transmission to humans.

Our review found a relatively low frequency of replication-competent SARS-CoV-2 in faecal and other gastrointestinal sources. Although it is biologically plausible, more research is needed using standardized cell culture methods, control groups, adequate follow-up, and robust epidemiologic methods, including whether secondary infections occurred, to determine the role of the oro-faecal route in the transmission of SARS-CoV-2.
Knowledge and perception of older adults toward end of life and advanced directive in Nigeria
Authors: Cadmus Eniola Olubukola , Oyinlola Oluwagbemiga , Obadare Abiola , Adebusoye Lawrence Adekunle , Mahmoud Kafayat
Published: November 2024

Objectives

Older adults often have a heightened awareness of death due to personal losses. In many low- and middle-income countries, including Nigeria, conversation about end-of-life issues and advanced care planning (ACP) among older adults is gradually emerging. Our study explored older adults’ knowledge and perceptions towards advanced directives and end-of-life issues in a geriatric care setting in Nigeria.

Methods

A cross-sectional study was conducted among older adults (aged ≥60 years) in a geriatric outpatient clinic. Data were collected using an interviewer-administered, semi-structured questionnaire, tested at a significance level set at alpha 0.05.

Results

The study included 204 participants with a mean age of 71.3 ± 7.2 years, predominantly female (67.2%). Few of the participants have heard about end of life (20.1%), living will (19.1%), power of attorney (19.6%), and ACP (25.9%). About 29.9% of the respondents considered having a living will, of which about 34.4% have written one. Only 23 (11.3%) would consider discussing ACP in the future, 32 (15.7%) would discuss place of care, and 30 (14.7%) place of death. Preparedness for end of life and knowledge of ACP was higher among males, those with formal education, and those with good self-rated health (p < 0.05).

Significance of results

The study highlighted gap in awareness and engagement in ACP among older adults in a country like Nigeria. This lack of knowledge can lead to inadequate end-of-life care and unpreparedness for critical health decisions for older adults in Africa. Thus, improving awareness and understanding of ACP can empower older adults, ensuring their end-of-life preferences are respected, enhancing the quality of care, and reducing the emotional and financial burden on families.
The Roots of Direct Democracy in the United States: South Dakota’s 1898 Referendum Creating the First Statewide Initiative Process
Authors: Dinan John , Heckelman Jac C.
Published: November 2024

We investigate voter preferences for changes in voting rules, focusing specifically on the creation of citizen-initiative processes that were originally adopted in South Dakota in 1898 and eventually enacted by half of the states. Various claims have been advanced about why the process was adopted and who supported or opposed it, but without presenting evidence from referenda where voters approved the creation of the process. We test these claims by examining county-level election returns from South Dakota’s 1898 referendum that created the first statewide initiative process in the United States. We find that support for the initiative process was generally higher among groups that are disadvantaged in various ways by existing representative institutions and perceive advantages in creating direct democratic institutions capable of bypassing representative processes. These findings stand in contrast to the notion that the adoption of constitutional rules will be relatively free from calculations rooted in self-interest and perceived advantage from the rules changes.
From Congress to the States: Explaining the Emergence and Membership of Freedom Caucuses in State Legislatures
Authors: Green Matthew N. , Gawehns Florian
Published: November 2024

Since 2017, Republican lawmakers in a growing number of US states have formed ideological intraparty organizations, modeled after the US House Freedom Caucus, that seek to move state policy further rightward. What explains the appearance of these state freedom caucuses, and what kinds of lawmakers are more likely to join them? We show that the creation of these caucuses was initially motivated by concerns that state-level legislative Republican parties are too ideologically heterogeneous but has since been driven by conservative entrepreneurs seeking to spread freedom caucuses nationally. We also provide evidence that conservative legislators are more likely to join a new state freedom caucus, as one would expect, but also that, in a few states, lawmakers who are more electorally vulnerable lawmakers or lack internal influence have also been more likely to join. These findings underscore how state-level ideological caucuses can appeal to members’ multiple goals and serve as instruments of vertical polarization in a federal system.
Quantitative Decoupling Analysis for Assessing the Meteorological, Emission, and Chemical Influences on Fine Particle Pollution
Authors: Wang Junhua , Ge Baozhu , Kong Lei , Chen Xueshun , Li Jie , Lu Keding , Dong Yayuan , Su Hang , Wang Zifa , Zhang Yuanhang
Published: November 2024

A comprehensive understanding of meteorological, emission and chemical influences on severe haze is essential for air pollution mitigation. However, the nonlinearity of the atmospheric system greatly hinders this understanding. In this study, we developed the quantitative decoupling analysis (QDA) method by applying the Factor Separation (FS) method into the model processes to quantify the effects of emissions (E), meteorology (M), chemical reactions (C), and their nonlinear interactions and impact on fine particulate matter (PM2.5) pollution. Taking a heavy‐haze episode in Beijing as an example, we show that different from the integrated process rate (IPR) and the scenario analysis approach (SAA) in previous studies, the QDA method explicitly demonstrate the nonlinear effects by decomposing the variation of PM2.5 concentration into individual contributions of E, M and C terms as well as the contributions from interactions among these processes. Results showed that M dominated the hourly fluctuation of the PM2.5 concentration. The C terms increase with increasing the level of haze, reaching maximum (0.37 μg m−3 h−1) at the maintenance stage. Moreover, our method reveals that there are non‐negligible non‐linear effects of meteorological, emission, and chemical processes during pollution stage, with the mean accounting for 50% of the increase in PM2.5 concentrations, which is often ignored in the current air pollution control strategies. This study highlights that the QDA approach can be used to gain insight into the formation of heavy pollution, and to identify uncertainty in numerical models.
Distinct causes underlie double-peaked trilobite morphological disparity in cephalic shape
Authors: Drage Harriet B. , Pates Stephen
Published: November 2024

Trilobite cephalic shape disparity varied through geological time and was integral to their ecological niche diversity, and so is widely used for taxonomic assignments. To fully appreciate trilobite cephalic evolution, we must understand how this disparity varies and the factors responsible. We explore trilobite cephalic disparity using a dataset of 983 cephalon outlines of c. 520 species, analysing the associations between cephalic morphometry and taxonomic assignment and geological Period. Elliptical Fourier transformation visualised as a Principal Components Analysis suggests significant differences in morphospace occupation and in disparity measures between the groups. Cephalic shape disparity peaks in the Ordovician and Devonian. The Cambrian–Ordovician expansion of morphospace occupation reflects radiations to new niches, with all trilobite orders established by the late Ordovician. In comparison, the Silurian–Devonian expansion seems solely a result of within-niche diversification. Linear Discriminant Analyses cross-validation, average cephalon shapes, and centroid distances demonstrate that, except for Harpida and the Cambrian and Ordovician Periods, order and geological Period cannot be robustly predicted for an unknown trilobite. Further, k-means clustering analyses suggest the total dataset naturally subdivides into only seven groups that do not correspond with taxonomy, though k-means clusters do decrease in number through the Palaeozoic, aligning with findings of decreasing disparity.
Liquid-liquid crystalline phase separation of spider silk proteins
Authors: Landreh Michael , Osterholz Hannah , Chen Gefei , Knight Stefan D. , Rising Anna , Leppert Axel
Published: November 2024

Liquid-liquid phase separation (LLPS) of proteins can be considered an intermediate solubility regime between disperse solutions and solid fibers. While LLPS has been described for several pathogenic amyloids, recent evidence suggests that it is similarly relevant for functional amyloids. Here, we review the evidence that links spider silk proteins (spidroins) and LLPS and its role in the spinning process. Major ampullate spidroins undergo LLPS mediated by stickers and spacers in their repeat regions. During spinning, the spidroins droplets shift from liquid to crystalline states. Shear force, altered ion composition, and pH changes cause micelle-like spidroin assemblies to form an increasingly ordered liquid-crystalline phase. Interactions between polyalanine regions in the repeat regions ultimately yield the characteristic β-crystalline structure of mature dragline silk fibers. Based on these findings, we hypothesize that liquid-liquid crystalline phase separation (LLCPS) can describe the molecular and macroscopic features of the phase transitions of major ampullate spidroins during spinning and speculate whether other silk types may use a similar mechanism to convert from liquid dope to solid fiber.
Screen-printed wearable sensors for continuous respiratory rate monitoring: fabrication, clinical evaluation, and point-of-care potential
Authors: Al-Halhouli Ala’aldeen , Albagdady Ahmed , Rabadi Alexander , Hamdan Musab , Abu-Khalaf Jumana , Abu-Abeeleh Mahmoud
Published: November 2024

A screen-printed wearable sensor accurately monitored respiratory rate in 15 participants with a 0.055 bpm error, showing promise for point-of-care use in conditions like COPD and COVID-19.
Unveiling the synergic potential of dual junction MoSe2/n-Ga2O3/p-GaN heterojunctions for ultra-broadband photodetection
Authors: Aggarwal Vishnu , Kumar Manish , Kumar Rahul , Gautam Sudhanshu , Yadav Aditya , Shrivastava Shikha , Dogra Anjana , Gupta Govind , Walia Sumeet , Kushvaha Sunil Singh
Published: November 2024

For practical optoelectronic applications, photodetectors capable of detecting light across a wide wavelength range (200–1100 nm) are essential.
Targeting drug resistance in breast cancer: the potential of miRNA and nanotechnology-driven delivery systems
Authors: Verma Aditi , Patel Krunal , Kumar Ashutosh
Published: November 2024

This review explores the synergistic administration of miRNA and chemotherapeutic agents to combat drug resistance in breast cancer, emphasizing cutting-edge drug delivery systems and their profound implications for clinical outcomes.
Exploring semiconductor potential: novel boron-based Ti3AlC2 and Ti4AlN3 MAX phase composites with tunable band gaps
Authors: Alam Md. Shahinoor , Chowdhury Mohammad Asaduzzaman , Islam Md. Saiful , Islam Md. Moynul , Sabur Md. Abdus , Rana Md. Masud
Published: November 2024

Here we have synthesized Ti4AlN3 and Ti3AlC2 MAX phase reinforced boron-based composites with tunable bandgaps for electronic and optoelectronic applications.
Synergistic effects of liquid phase exfoliated molybdenum based 2D nanosheets and MWCNTs for high performance supercapacitors
Authors: Malik Riya , Rana Ankur , Rana Megha , Singh Dilip K. , Srivastava R. , Suman C. K.
Published: November 2024

This work investigates the application of liquid phase exfoliated Mo-based transition metal dichalcogenide (TMDC) 2D-nanosheets integrated with multi-walled carbon nanotubes (MWCNTs) as electrode material for high-performance supercapacitors.
Enhancing School Health Monitoring through Teacher Training and Web-Based Applications
Authors: Arini Merita , Suryanto Farid , Puspita Gina , Primastuti Harumi Iring
Published: November 2024

Monitoring children’s health is critical for ensuring growth and development. However, non-integrated recording and reporting methods often result in inconsistent and inaccurate data. This study aims to increase knowledge and skills in monitoring children’s health in elementary schools, from anthropometric measurements to recording and reporting. The method used was a quasi-experiment (non-control, non-randomization) involving teachers, school staff, and related officers (n=25). The intervention consisted of educational and training sessions in anthropometric measurements, monitoring children’s growth and development, and training on using MySIMOKA, a web-based application for monitoring children’s health and training. Evaluation is carried out by providing a pre-test and a post-test. The intervention significantly increased participants’ knowledge (p=0.001). The calculated effect size of 0.47 shows that the intervention has a medium effect, confirming the effectiveness of education and training in increasing participants’ knowledge. Participants also showed improvement skills for the children’s examination. MySIMOKA system usability scale was 66.72, meaning the system still needs to be improved. Health education and training sessions and practicing MySIMOKA significantly improve participants’ knowledge and skills regarding monitoring children’s health in elementary schools. Further assistance and cross-sector collaboration are needed to ensure the sustainability of child health monitoring and data entry.
Influence of Mo addition on microstructural and mechanical characteristics of TiXMo5Cu alloys manufactured by powder metallurgy
Authors: Kurt Murat , Ozgun Ozgur , Ekinci Omer , Balalan Zulkuf
Published: November 2024

In the present study, TiXMo5Cu alloys were produced utilizing the powder metallurgy technique. Alloy samples with different ratios of Mo added were shaped by uniaxial pressing under 550 MPa pressure. The shaped samples were subjected to a sintering process at 5 different temperatures for a waiting time of 180 min in a 99.99% pure argon gas atmosphere. The densities of the fabricated specimens were found with the Archimedes principle. Microstructures of the obtained samples were attained by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) examinations. For the determination of the mechanical characteristics, micro hardness and tensile tests were applied. According to the density measurements, the highest relative density values were attained with the sintering temperature of 1300 °C, and a higher Mo ratio resulted in a lower relative density. The microstructure of the fabricated specimens is comprised of α-Ti and β-Ti phases. The α-Ti phase ratio in the microstructure reduced based on rising Mo, while the ratio of the β-Ti phase increased. Accordingly, while the hardness values increased, the strength values decreased.
Indocyanine Green Marking of Axillary Sentinel Lymph Nodes in Early Breast Cancer
Authors: Hartmann Steffi , Plonus Meri-Liis , Schultek Gesche , Stubert Johannes , Gerber Bernd , Reimer Toralf
Published: November 2024

Axillary sentinel lymph node excision (SLNE) in breast cancer patients with clinically node-negative disease may be carried out using different tracers. The standard tracer is technetium colloid (99mTc). Indocyanine green (ICG) can be used as an alternative. This study aimed to evaluate the clinical usefulness of this fluorescent dye in a standardized setting.

A prospective, single-center cohort study carried out at the University Gynecological Hospital of Rostock from September 2023 to May 2024 carried out sentinel lymph node marking using only ICG in patients with breast malignancies. The ICG injection was administered immediately after the induction of anesthesia. Detection of the sentinel lymph node (SLN) was done using a laparoscopy system suitable for ICG. The aim was to determine the detection rate (DR) for SLNs marked exclusively using ICG and to record any complications. The costs of using ICG to mark SLNs were compared with those for 99mTc marking.

During the study period, contraindications against marking with ICG were ascertained for five (3.8%) of 132 patients with planned SLNE. A total of 100 SLNEs were carried out after ICG marking in patients who met the inclusion criteria in the context of the study. A median of two SLNs were resected. The detection rate (DR) for SLNs was 98.0%. SLNs were identified in all obese patients. No serious systemic side effects occurred following ICG injection. Transient skin discoloration in the area around the injection site were observed in eight patients. The direct cost of ICG marking was 62.73 Euros, which was 170.36 Euros lower than the cost of 99mTc marking.

The detection rate of axillary SLNs marked using ICG is high and the method is cost-effective, has few side effects and can also be used in obese patients. Contraindications against the administration of ICG are rare. Marking with ICG is a good alternative to the 99mTc method and offers advantages in terms of costs, logistics, no exposure to radiation, and patient comfort.
Pulmonary Vascular Disease in Chronic Obstructive Pulmonary Disease
Authors: Kay Dana , Bernardo Roberto , Elwing Jean
Published: November 2024

Pulmonary hypertension (PH) is a vascular disease characterized by pulmonary artery remodeling and right heart failure. PH related to COPD is a precapillary form of the disease, with hemodynamic measurements including a mean pulmonary artery pressure of greater than 20 mm Hg, a wedge pressure of less than 15 mm Hg, and a pulmonary vascular resistance of greater than 3 WU (Woods units), categorized under the World Health Organization classification as group 3. The presence of PH in COPD has been known to increase morbidity and mortality. Limited studies have evaluated treatment options for PH related to COPD.
Empagliflozin Raises Sodium in SIADH Patient, Enabling Timely Surgery
Authors: Abouglila Kamal , Gatnash Mouad
Published: November 2024

Empagliflozin, a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor, induces osmotic diuresis via glucosuria and may represent a novel therapeutic approach for managing syndrome of inappropriate antidiuretic hormone secretion (SIADH). This case report details the successful use of empagliflozin to correct persistent hyponatremia in a 78-year-old man with SIADH, awaiting elective abdominal surgery for hernia repair over several months. The patient, who had a history of hypertension and multinodular thyroid goiter with normal thyroid function tests, continued to experience low serum sodium levels despite discontinuing enalapril, previously used for hypertension management. An extensive evaluation confirmed a diagnosis of SIADH, with sodium levels initially ranging between 124 and 128 mmol/L. Traditional management, including fluid restriction, failed to normalize his sodium levels, leading to repeated cancellations of his scheduled surgery due to persistent hyponatremia. In October 2023, treatment with empagliflozin was initiated, leading to a gradual increase in sodium levels. Within 3 weeks, his serum sodium had normalized to 134 mmol/L, accompanied by a rise in serum osmolality. As a result, the elective surgery was successfully performed without complications. These findings suggest that empagliflozin, in combination with fluid restriction, offers a promising treatment option for improving sodium levels in patients with SIADH, helping avoid unnecessary delays in elective surgical interventions.
Navigating COPD in Aging Populations: Insights Into Pathophysiology and Comprehensive Care
Authors: Atchley William T. , Montgomery Amy , Seth Rohan , Gandhi Tanmay , Brewer Shannon
Published: November 2024

Chronic obstructive pulmonary disease (COPD) poses a significant and growing health burden among aging populations, marked by increasing prevalence and complex management challenges specific to elderly patients. This review explores the multifaceted interplay between COPD and aging, highlighting overlapping pathophysiological processes and comorbidities that complicate diagnosis and treatment. We examine age-specific management strategies, emphasizing the need for tailored approaches that account for the unique physical, cognitive, and health-related quality of life impacts on older adults. Additionally, we discuss preventive treatments and the critical roles of mental health, end-of-life care, and caregiver support in comprehensive disease management. The importance of integrative approaches to enhancing health care delivery is also underscored. Finally, we outline future directions, focusing on novel treatment pathways and the identification of biomarkers for early detection. Addressing these elements is essential for optimizing care in this vulnerable population and alleviating the significant societal and economic impacts of COPD among aging patients.
Orthogonally polarized dual-wavelength Nd:LiYF4 laser at 1777 and 1789 nm with 1:1 output power ratio
Authors: Wang Shuang , Li Changli
Published: November 2024

A diode-pumped continuous-wave orthogonally polarized dual-wavelength Nd:LiYF4 (Nd:YLF) laser on 4F3/2 → 4I15/2 transition is studied. The output power ratio can be adjusted using two intracavity uncoated glass plates. At an incident pump power of 20 W, a dual-wavelength laser operating at 1777 nm in π-polarization and 1789 nm in σ-polarization was realized. The total output power of the dual-wavelength laser was more than 1.16 W with a 1:1 output power ratio. The total slope efficiency and total optical conversion efficiency with respect to the incident pump power were 4.6% and 2.9%, respectively. To the best of our knowledge, this is the first work realizing mid-infrared wavelength operation in Nd:YLF lasers on 4F3/2 → 4I15/2 transition.
Study on the Effect of Nitrogen Bubble Foam Flooding in Deep Heavy Oil Reservoirs with Edge And Bottom Water
Authors: Ma Qian , Ma Jun-jie , Zhao Ju-ju , Wei Wen-zong , Zhao Xiao
Published: November 2024

The oil recovery rate is low, the degree of recovery is low and the water content rises fast after water flooding in deep edge and bottom water heavy oil reservoir in Lukeqin oilfield. In order to explore the method to improve the production effect, the integrated foam system of high temperature and high pressure resistant viscosity reduction and oil displacement is optimized. On the basis of clarifying the mechanism of improving the production effect of nitrogen foam flooding for deep heavy oil, taking the west area of Lukeqin oilfield as the research object, the parameter optimization design of nitrogen foam flooding for deep edge and bottom water heavy oil is carried out, such as injection section plug, gas-liquid ratio and injection-recovery ratio. The optimization results are as follows: the injected nitrogen foam slug is 0.2pv, the gas-liquid ratio is 1-1.2, and the injection production ratio is 1:1. The pilot test of 4 well groups was carried out on the site. After foam flooding, the injection pressure was increased by 5.2mpa, the daily oil production of the oil well was increased by 43T / D, the water cut was decreased by 45%, the accumulated oil production was increased by 32000 tons, and the oil recovery was expected to be increased by more than 10%. The purpose of improving the development efficiency of this type of oil reservoir was achieved. Using this optimization technology for scheme design and field implementation, the oil enhancement effect is remarkable and improves the benefit of deep thick oil development, which can provide technical support for the development of similar domestic reservoirs.
Research on Characteristics and Centrifuge Treating Chemical of Floccules Generated by ASP Flooding Produced Water Treatment
Authors: Ai Guang-zhi , Wu Di , Xue Qiang , Zhang Hui-ping
Published: November 2024

The addition of composite water clear agents (acid, inorganic coagulant and organic flocculant) was an effective method for the treatment of the high ASP contents produced water about strong alkali system. However, it formed a large amount of flocs, which poses significant environmental pressure. In order to reduce the production of flocs, chemical analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and other methods were used to study the composition and structure of flocs generated in the treatment of produced water. It was found that the reason for the difficulty in flocs dewatering was that the gel generated by the action of polyacrylamide in produced water and water cleaning agent contained strong hydrophilic groups and formed a three-dimensional network structure. In view of this feature of flocs, concentrated treatment agent research was carried out from the ideas of degradation, coagulation, density regulation, etc. Field trials have shown that adding 1% of the treatment agent, the water content of the flocs after centrifugal treatment was reduced from 97% to 73% and its volume was reduced by 89%. The flocs concentration treatment agent solved the problem of large flocs production in the application process of composite water clear agents, and was of great significance in the oilfield environment protecting and green production.
A New Method of Using Production Data to Predict the Effect of Oil Well Liquid Lifting Based on Deep Learning
Authors: Lu Shuiqingshan , Cui Chuanzhi , Wu Zhongwei , Qian Yin , He Jiajie
Published: November 2024

Liquid lifting is a low-cost, straightforward, and efficient measure for stabilizing production, achieved by adjusting liquid production to reduce bottom-hole flow pressure, thereby optimizing reservoir development and increasing recovery rates. However, traditional research methods for liquid lifting no longer meet the demands of contemporary oilfield big data applications. Particularly in the selection of target wells for liquid lifting, manual screening based on chart methods faces challenges such as low efficiency, high workload, and poor generalization capabilities. This study focuses on the oil wells in the high water cut phase of the SL oilfield in China and proposes a novel data-driven approach to predict the liquid lifting effects of oil wells. This method forecasts the effect of liquid lifting measures based on dynamic and static production data before the implementation of liquid lifting measures, facilitating intelligent selection of oil wells for liquid lifting measures. Firstly, each evaluation metric is assigned weights by utilizing the Coefficient of Variation-G1 Hybrid Cross-Weighting method. The comprehensive evaluation score is obtained through a weighted sum. Subsequently, the self-organizing map (SOM) clustering method is applied to categorize the oil well liquid lifting effects into four classes (A, B, C, D), representing different levels of effect. Additionally, a learning sample dataset is constructed by selecting multidimensional time-series features before liquid lifting. The oil well liquid lifting effect classification model is established using the Bi-LSTM sequence-to-label deep learning algorithm. Comprehensive testing validates the superior performance of the model, especially with classification accuracies of 0.96 and 0.83 on the training and testing sets, respectively. These results outperform other classification models such as LSTM, XGBoost, and SVM, providing an effective tool for intelligent oil well selection in liquid lifting measures.
Research on Numerical Simulation Methods for Water Invasion Dynamics in Fractured Gas Reservoirs with Water Content
Authors: Ruan Jifu , Yi Jin , Li Xinling , Chen Chunyan , Li Xianghong
Published: November 2024

Fractured gas reservoirs with water have complex gas-water relationship, large permeability difference between matrix and fracture, complex gas-water percolation mode, rapid production decline, short stable production period and large reduction of recovery factor due to water production of gas wells, which poses great challenges to efficient development of gas fields. The fracture system is the main channel for the edge and bottom water channeling of gas reservoirs. It is the core issue to understand the water invasion dynamic characteristics of such gas reservoirs to accurately depict the fracture geometry occurrence and truly simulate the gas-water two-phase flow mechanism in the fracture-matrix dual media. Taking the Jia-2 gas reservoir in Moxi gas field as an example, a discrete fracture model construction method that explicitly characterizes the fracture system is proposed. Based on the discrete fracture model, a mathematical model of gas-water two-phase flow in the fracture-matrix dual system is constructed and numerically solved. The influence mechanism of fracture opening, length, density and occurrence on the water invasion performance of multi-layer gas reservoirs is discussed, and the main control factors of the water invasion and water channeling law of fractured water gas reservoirs are identified. The application shows that the water invasion dynamics of gas reservoirs based on the discrete fracture model are more consistent with the actual conditions of the mine, providing a theoretical basis for deepening the understanding of water invasion dynamics of this type of gas reservoirs, optimizing the gas well working system, and formulating targeted water control countermeasures..
Development and Application of a Chelating Acid for Water Injection Wells of Chang 6 Reservoir of An-Sai Oilfield
Authors: Wan Xiang-hui , Zheng Wei-shi , Jiang Wen-xue , Chen Ying-hua , Li Yong , Zhang Bin
Published: November 2024

Ansai oilfield is a typical low permeability, low pressure, low yield and serious heterogeneity oilfield. Chang 6 play of Triassic YanChang Formation is a typical ultra-low permeability reservoir. The average porosity of the reservoir is 10 % ~ 14 %, and the average permeability is (0.2 ~ 4.0) × 10−3 μm2. The absolute content of clay minerals in the reservoir is relatively high, with an average content of 18.61 %. The main components are kaolinite, chlorite, illite and illite/montmorillonite interlayer. Due to the reservoir blockage caused by scaling, water sensitivity and formation particle migration in the process of water injection, high injection pressure and under injection wells is increasing dramatically. In view of the above challenges, a fit-for-purpose acid, which contains organic acids and chelating agents, was developed for injection pressure reduction and injection enhancement. It has the characteristics of strong dissolution, good retarding and corrosion inhibition performance. Corrosion rate is 0.5632 g / (m2·h) for J55 steel in 24h, and the core permeability increases by 74.57 % after acid flooding. It has been applied in field test of 3 wells in Chang 6 layer of Ansai oilfield since March 2024. The average daily injection volume increased by 37.87 %, and the validity period was more than 180 days.
Effect of Solid Particles in Polymer Waste Liquid on Grinding Tool Wall Erosion
Authors: Bingyu Sun , Hanxiang Wang , Shen Fan , Jingwen Ren , Yi Yuan , Yuting Wang
Published: November 2024

With the continuous accumulation of polymer waste liquid in the third oil recovery process, the treatment of wellhead return waste liquid has become a key issue in oilfield exploitation and environmental protection. In this paper, the erosion failure of the cutter caused by sand-containing particles in the waste liquid during the shear grinding process is studied. The influence of the main structural parameters of the grinding tool and the erosion failure is studied by using the comprehensive numerical simulation method to reduce the erosion rate of the polymer flooding waste liquid on the cutter. Firstly, the flow field model of the solid-liquid fluid is established, and the erosion phenomenon on the tool wall is studied by combining the model with field experiments. In addition, the relationship between the different cutters structure and erosion rate of the grinding tool is studied, and the mathematical model is established. The optimized structural parameters are given to enhance the erosion resistance of the grinding tool in the process of polymer flooding wellhead waste liquid treatment and prolong its service life.
Research and Application of Intelligent Well Completion Technology in Offshore Oilfield
Authors: Zhang Qilong , Li Zhong , Weng Haoyang , Liu Wei , Huang Zhongwei , Zhang Bin
Published: November 2024

The reservoirs in Bohai oilfield were mainly composed of unconsolidated sandstone. A single multi-layer gravel packing operation could greatly reduce the packing operation time and improve the operation efficiency. However, the conventional tools were limited by the double-layer central tube structure, which resulted in large packing friction and high pressure consumption due to its small annular area, which limited the limit operation length and displacement. In order to solve this problem, we independently developed a double-layer screen tube one-time multi-layer fracturing packing tool, innovatively set up production interlayer in the screen pipe, formed a bypass diversion screen pipe system, so as to reduce the downward entry of one layer of central pipe during filling, simplify the structure of the filling string, and greatly reduce the friction of the string. The results showed that the limit packing length and displacement were 1200m and 45bpm respectively, which were 300% and 50% higher than the traditional packing tools, and the operation range of the tools was improved. The safety and efficiency of double screen fracturing and filling operation were ensured by innovating the quick connection method of double screen pipe, fast pressure test tool and expanding switch tool of oil pipe. The application in well LX has realized the purpose of sand control by five layers filling in one time. The packing length was more than 400 m. Combined with the problems in field operation, it had been applied in 5 areas The improvement suggestions of the tool are put forward. The double screen pipe one-time multi-layer fracturing packing tool and its supporting technology realized the ideal packing parameter requirements of low pump pressure and high return velocity. It could be widely used in sand control operation of multi-layer gravel packing fracturing in large-span perforation section in the future, which greatly improved the operation efficiency and has good economic benefits and promotion value.
Favorable Diagenesis and Pore Evolution of The Qi-2 Member Reservoir in the Hechuan-Tongnan Area
Authors: Liu Yunmiao
Published: November 2024

This article takes the Qi-2 member dolomite reservoir in the Hechuan-Tongnan area as the research object, and combines research methods such as drilling cores, thin section analysis, CT scanning, and geochemical analysis to deeply explore the pore structure characteristics, diagenetic characteristics, and influencing factors on pore evolution of the Qi-2 member dolomite reservoir. This results indicate that: ①The Qi-2 member should develop two types of reservoir spaces: pores and fractures. The reservoir space is mainly composed of intercrystalline dissolved pores (0.5∼5%), dissolved fractures and dissolved cavities (2∼4%). The intercrystalline pores are relatively evenly distributed, and the fractures improve the connectivity of pores. The reservoir space of the poor gas layer is mainly composed of biocast pores and intragranular dissolved pores (1∼2%), which are relatively isolated; ② The matrix pores of the Qi-2 member are relatively evenly distributed, with a radius of 200μm~600μm is the main focus. The throat radius is mainly 20μm~60μm fine throats.③According to the effect of diagenesis on pore evolution of dolomite reservoir in Qi-2 formation, it can be divided into constructive and destructive. The formation of reservoir space is mainly caused by quasi-syngenetic atmospheric fresh water erosion, and the matrix pores are mainly intercrystalline pores and intercrystalline dissolved pores. The early dolomitization is the key factor of pore preservation. The geological study of dolomite reservoir of the Qixia Formation in the Daqing exploration area has been enhanced, providing strong basis for reservoir prediction and deployment in the later stage.
A Study on the Paleoclimate and Sedimentary Environment of the Upper Kuli Formation in the Hailar Basin
Authors: Tian Yu , Xue Yunfei , Liu Yunmiao , Liu Ming , Bu Chunyang , Gong Xuenan
Published: November 2024

The Kuli Formation in the Hailar Basin has a wide distribution range, complex and variable lithology, and oil and gas indications during field investigations, which has great research significance and value. In order to better understand the paleoclimate and sedimentary environment of the Upper Kuli Formation, this article uses three methods for the first time: heavy mineral analysis, sporopollen fossils identification, and inorganic element analysis. Based on the characteristics of heavy mineral assemblages, sporopollen fossils identification, and element analysis correspond to the five bottom layer combinations of heavy mineral analysis, analyzing their respective combination characteristics and change patterns. With a more comprehensive perspective and higher time resolution, Cross validation improves the accuracy and credibility of its inference. The results indicate that the Upper Kuli Formation can be divided into five combinations from bottom to top. The paleoclimate underwent a transition from a humid environment to a drier environment. The sedimentary environment has undergone a transition from a deep-water environment to a shallow water environment, transitioning from dynamic, rapid sedimentation, and strong terrestrial influences to a sedimentary environment dominated by more static water, chemical precipitation, and diagenesis. This study combines different geological and geochemical analysis methods to provide strong basis for inferring the paleoclimate and sedimentary environment of the Upper Kuli Formation. The research results are of great significance for interpreting geological changes such as paleoclimate change and ecosystem evolution.
Analysis of Corrosion Causes and Optimization of Corrosion Evaluation Methods for Water Injection System in Changqing JY Oilfield
Authors: Zhijie Hu , Jinliang Du , ying Si Yang , Xiaoling Wang , Huan Li
Published: November 2024

Based on the corrosion characteristics of the water injection system in Changqing Oilfield, an experimental study was conducted on the corrosion of the water injection system caused by carbon dioxide, hydrogen sulfide, bacteria, and water treatment agents in the produced liquid. The main influencing factors of corrosion in the water injection system were analyzed, and it was clarified that the corrosion of the water injection system in Changqing Oilfield was mainly caused by oxygen corrosion, which also had an impact on the water quality of the injection. Combining static corrosion analysis with the introduction of pitting and dynamic corrosion rate testing methods, the average corrosion rate of JY oilfield water injection system has a positive correlation with pitting corrosion, while the average corrosion rate of clean water has a stronger correlation with pitting corrosion. The corrosion evaluation method has been optimized, providing technical basis for formulating effective anti-corrosion measures for the oilfield.
Reliability Analysis of Subsea Riser System Based on Fuzzy Fault Tree Analysis Method
Authors: Zhou Chuankun , Liu Jian , Yu Xiaolong , Jiao Zihao , Zhang Guangfei , Liu Chao , Chen Yaqi
Published: November 2024

To deal with the complex structure of subsea riser system and the lack of failure statistics and insufficient information during operation, a fuzzy fault tree analysis (FFTA) method is applied to analyse the reliability of the subsea riser system, and a qualitative and quantitative analysis is carried out by establishing a fault tree model of the riser system to obtain the minimum set of cuts and the basic events. The fuzzy importance degree of each fundamental event is determined as well as the failure probability of the headline event of the fuzzy fault tree, “failure of subsea riser system,” using the triangular fuzzy number computation method. Finally, the “average value” method of comprehensive analysis of the fault tree model, the analysis results show that the bottom event riser check valve, riser buoyancy device, riser working medium isolation valve, riser line, riser gas lift device and other components of the failure of the subsea riser system is relatively the weak links, compared with the actual situation, the analysis results in line with the actual engineering situation, these five aspects should be regularly detected and focused on prevention. In conclusion, this research helps to comprehensively analyse the reliability of the riser system and take into account the uncertainty factors, and provides more accurate guidance on the reliability constraints for the localized design and production of subsea riser system.
The Flowback Proppant Scaling Mechanism in the Horizontal Shale Oil Wells of Qingcheng Oilfield
Authors: Yang Le , Li Qiongwei , Li Kai , Yuan Huiying , Qi Yin , Mu Lijun , Yang LiHua , Guo Gang , Wang Weijun
Published: November 2024

Proppant scaling in the horizontal shale oil wells is a common problem in the Qingcheng Oilfield, one of the largest shale oil producers in China. However, few studies have focused on the mechanism of the proppant scaling during the flowback stage of hydraulic fracturing. To elucidate the scaling mechanism, in this study we collected the samples of produced water and solid scales and analyzed their compositions. The experimental simulations of the static and dynamic scaling processes using fracturing fluids, formation water, and reservoir rocks were also performed.

In these experiments, the scale was found to be mainly SiO2 combined with FeCO3 and/or CaCO3. FeCO3 was dominant at the initial stage of the flowback, and CaCO3 became dominant at later stages of the flowback and during the stable production stage. It is believed that the high percentage of ferrous minerals (e.g., 46.4% of ferrocalcite) in multiple formation rocks is an essential reason that the proppant scaling happened during the flowback stage. The Fe2+ and Ca2+ ions were believed to be released via reservoir rock reacting with the fracturing fluid under the reservoir temperature and pressure (e.g. 60 °C, 20MPa). In addition, the FeCO3 formed in the initial flowback stage of the fracturing has the greatest impact on production.
Research and Application of Drilling and Completion Technology for Cluster Wells
Authors: Jiang Peng , Li Lihua , Fu Yueying
Published: November 2024

Huabei Oilfield has a wide range of oil and gas resources. With the pressure of environmental protection and the need for high-quality and cost-effective exploration and development, cluster drilling has also put forward higher requirements. In this oilfield, there is no effective technology in large cluster reservoir, integrated design of drilling and production, surface engineering, intensive construction, recycling of drilling fluid and so on. Taking a block in Bayan as the research focus, combined with geological characteristics, and by means of experiment and theoretical analysis, this paper focuses on the optimization of wellhead layout, trajectory optimization and drilling fluid recycling technology of cluster well, and forms the cluster well drilling and completion technology that is suitable for reservoir characteristics in the target area of Huabei Oilfield, so as to achieve the purpose of reducing cost and increasing efficiency, speeding up production and construction and expanding space.