Search Results (86)

We investigated the use of gravel packing sand control technology in multi-lateral horizontal wells to support the development of natural gas hydrate reservoirs. An experimental apparatus was developed to investigate the effects of well configurations and operational parameters on ultra-light sand packing behavior and to estimate the field operational parameters through the application of similarity criteria. The results showed that the ultra-light sand packing process includes four stages in a single horizontal main bore, i.e., sand bank formation, alpha-wave, beta-wave, and simultaneous annulus packing, and two stages in lateral wellbores: a sand bank formation and then an alpha-wave pattern or an initial alpha-wave pattern followed by a slope pattern. At comparable injection rates and sand concentrations, the packing sequence is predominantly governed by leakage rates and the quantity of lateral wellbores. When the lateral wellbore is 1 m and the leakage rate exceeds 20%, the lateral packs first. When the lateral wellbore is 2 m and the leakage rate is below 30%, the main bore packs first. For the field prototype (480 m main bore and 200 m lateral wellbore), the deviation angle of lateral wellbores should be controlled within 30°, and it is recommended that the distance between the junction point and the heel of the horizontal main bore be 160 m. When the leakage rates exceed 50%, the recommended injection rates are less than 1.69 m³/min. When the leakage rates range from 10 to 50%, the recommended injection rates range from 1.69 to 3.38 m³/min, with predicted end-of-packing pressures ranging from 6.56 to 19.92 MPa. This study provides valuable insights into the development of gravel packing sand control technologies in a multi-lateral horizontal well for hydrate reservoirs. Full article

This paper presents a comprehensive review and theoretical analysis of integrating Cyclic Solvent Injection (CSI) with multilateral well (MLW) technologies to enhance heavy oil recovery. Given that many MLW configurations inherently exhibit symmetrical geometries, CSI–MLW integration offers structural advantages for fluid distribution. CSI offers a non-thermal mechanism for oil production through viscosity reduction, oil swelling, and foamy oil behaviour, but its application is often limited by poor sweep efficiency and non-uniform solvent distribution in conventional single-well configurations. In contrast, MLW configurations are effective in increasing reservoir contact and improving flow control but lack solvent-based enhancement mechanisms. In particular, symmetrical MLW configurations, such as dual-opposing laterals and evenly spaced fishbone laterals, can facilitate balanced solvent distribution and pressure profiles, thereby improving sweep efficiency and mitigating early breakthrough. By synthesizing experimental findings and theoretical insights from the existing literature, laboratory studies have reported that post-CHOPS CSI using a 28% C₃H₈–72% CO₂ mixture can recover about 50% of the original oil in place after six cycles, while continuous-propagation CSI (CPCSI) has achieved up to ~85% OOIP in 1D physical models. These representative values illustrate the performance spectrum observed across different CSI operational modes, underscoring the importance of operational parameters in governing recovery outcomes. Building on this foundation, this paper synthesizes key operational parameters, including solvent composition, pressure decline rate, and well configuration, that influence CSI performance. While previous studies have extensively reviewed CSI and MLW as separate technologies, systematic analyses of their integration remain limited. This review addresses that gap by providing a structured synthesis of CSI–MLW interactions, supported by representative quantitative evidence from the literature. The potential synergy between CSI and MLW is highlighted as a promising direction to overcome current limitations. By leveraging geometric symmetry in well architecture, the integrated CSI–MLW approach offers unique opportunities for optimizing solvent utilization, enhancing recovery efficiency, and guiding future experimental and field-scale developments. Such symmetry-oriented designs are also central to the experimental framework proposed in this study, in which potential methods, such as the microfluidic visualization of different MLW configurations, spanning small-scale visualization studies, bench-scale experiments on fluid and chemical interactions, and mock field setups with pipe networks, are proposed as future avenues to further explore and validate this integrated strategy. Full article

This research examines the compounding risks of global environmental change, including climate change, environmental law, biodiversity loss, and pollution, which threaten the stability of economic systems worldwide. While digital technology and global governance regulation are increasingly being proposed as solutions, their synergistic potential in advancing economic sustainability has been less explored. How can these technologies mitigate environmental risks while promoting sustainable and equitable development, aligning with the Sustainable Development Goals? We analyze policy global environmental data from the World Bank and the United Nations, as well as literature reviews on digital interventions, artificial intelligence, and smart databases. Global environmental change presents economic stability and rule of law threats, and innovative governance responses are needed. This study evaluates the potential for digital technology to be leveraged to enhance climate resilience and regulatory systems and address key implementation, equity, and policy coherence deficits. Policy recommendations for aligning economic development trajectories with planetary boundaries emphasize that proactive digital governance integration is indispensable for decoupling growth from environmental degradation. However, fragmented governance and unequal access to technologies undermine scalability. Successful experiences demonstrate that integrated policies, combining incentives, data transparency, and multilateral coordination, deliver maximum economic and environmental co-benefits, matching digital innovation with good governance. We provide policymakers with an action plan to leverage technology as a multiplier of sustainability, prioritizing inclusive governance structures to address implementation gaps and inform legislation. Full article

Real-time positioning is a technological field with a multitude of applications, which expand across many scopes: from positioning within a large area to localization within smaller spaces; from locating people to locating equipment; from large-scale industrial or military applications to commercially available solutions. There are at least as many implementations of real-time positioning as there are applications and challenges. Within the domain of Radio Frequency (RF) systems, positioning has been approached from multiple angles. Some of the more common solutions involve using Time of Flight (ToF) and time difference of arrival (TDoA) technologies. Within TDoA-based systems, one common limitation stems from the computational power necessary to run the multi-lateration algorithms at a high enough speed to provide high-frequency refresh rates on the tag positions. The system presented in this study implements a complete hardware and software TDoA-based real-time positioning system, using wireless Ultra-Wideband (UWB) technology. This system demonstrates improvements in the state of the art by addressing the above limitations through the use of a hybrid Machine Learning solution combined with algorithmic fine tuning in order to reduce computational power while achieving the desired positioning accuracy. This study presents the design, implementation, verification and validation of the aforementioned system, as well as an overview of similar solutions. Full article

Multilateral wells can effectively develop complex reservoirs at a lower cost, which, in turn, enhances the overall efficiency of oilfield exploitation. However, drilling branch wells from the main wellbore can disrupt the surrounding formation stresses, leading to secondary stress concentration at the junctions, which, in turn, causes wellbore instability. This study established a coupled analysis model for wellbore stability in branch wells by integrating seepage, stress, and damage. The model explained the instability mechanisms of branch wellbores under multi-physics coupling conditions. The results showed that during drilling, the thin, interwall section of branch wells had weak resistance to external loads, with significant stress concentration and a maximum damage factor of 0.267, making it prone to instability. As drilling time progressed, fractures in the surrounding rock mass of the wellbore continuously formed, propagated, and interconnected, causing a sharp increase in the permeability of the damaged area. The seepage direction of drilling fluid in the wellbore tended towards the severely damaged interwall section, leading to a rapid increase in pore pressure there. With increasing distance from the interwall tip, the resistance to external loads strengthened, and the formation damage factor, permeability, pore pressure, and equivalent plastic strain all gradually decreased. When the drilling fluid density increased from 1.0 g/cm³ to 1.5 g/cm³, the maximum equivalent plastic strain around the wellbore decreased from 0.041 to 0.014, a reduction of 65.8%, indicating that appropriately increasing the drilling fluid density can effectively reduce the risk of wellbore instability. Full article

The capability approach, shaped by Amartya Sen and Martha Nussbaum, offers an innovative normative framework for social work with disadvantaged children and adolescents. Unlike purely resource- or income-oriented approaches, it asks what real opportunities young people have to lead the lives that they value. At its core is the question of how these young individuals can develop their talents, build relationships, and participate in community and culture. The potential of the capability approach becomes particularly evident in social problem contexts often characterized by poverty, educational disadvantages, or discrimination. It emphasizes the importance of freedoms, self-determination, and agency, viewing children not merely as in need of assistance but as active agents in shaping their own lives. For social work practice, this opens up new possibilities for designing interventions in a participatory manner, ensuring that children’s needs and values are taken into account. Instead of standardized solutions, individualized and context-sensitive strategies are promoted. This approach also calls for a multilateral perspective: beyond individual casework, societal and institutional structures must be addressed. Only by removing barriers in areas such as education, health, and housing can real opportunities be created. At the same time, the concept aligns well with children’s rights work, trauma-sensitive approaches, and interdisciplinary collaboration. Although operationalizing the approach is complex, a capability-oriented perspective allows for a comprehensive assessment of children’s living conditions. In this way, social work can increasingly focus on strengthening agency and recognizing young people as subjects of their own becoming. Full article

This study explores creative tourism strategies in community-based tourism for sustainable development, focusing on the millennium-old Ban Chiang UNESCO World Heritage site in Thailand. It aims to uncover how creative tourism strategies support community-based tourism by optimizing development through cultural preservation, heritage revitalization, and sustainable outcomes. The research investigates how creative tourism approaches foster community-based tourism and how a community achieves sustainable socio-economic growth using the Community Capitals Framework (CCF). Using a qualitative case study approach, this research employs in-depth interviews, participant and non-participant observation, and document analysis to explore the interactions between creative tourism, community-based tourism, and sustainability. The findings reveal that creative tourism strategies can promote environmental conservation, cultural preservation, economic empowerment, and social well-being in Ban Chiang. This study highlights the successful development of strategies and collaborative actions by Ban Chiang’s community enterprise network for creative tourism progression, emphasizing multilateral stakeholder collaboration in enhancing community capital. The research proposes a model for creative tourism strategy and community capital development aimed at sustainability. It provides valuable insights for policymakers, practitioners, and local communities aiming to leverage creative tourism for sustainable development. By emphasizing the synergies between creative tourism and community-based tourism, it offers practical guidance for enhancing destination management, fostering community engagement, and promoting cultural and environmental conservation. This study bridges a critical gap in the literature by demonstrating how the CCF can be implemented to create positive impacts on creative tourism in heritage destinations such as Ban Chiang, presenting novel insights into its potential as a driver for positive transformation. Full article

Horizontal and multilateral well EGSs can potentially achieve the high-heat extraction of HDR. Herein, the performance of a multilateral horizontal well system in geothermal exploitation was investigated based on the geothermal and geological conditions of Qiabuqia geothermal field. The target reservoir is a granitic basement at 2650–3650 m depth, with initial temperatures of 151–190 °C. The simulation results indicate that the initial production temperature and electric power reached 178.4 °C and 2.90 MW and decreased by 8.3% and 17.9% over 20 years of production under the scheme of injecting 60 °C cold water at 50 kg/s, respectively. The reduction in total greenhouse gas (GHG) emissions amounts to 0.15–0.51 Mt relative to a fossil fuel plant. The multilateral horizontal well EGS outperforms conventional double vertical wells in terms of production temperature and electric power generation. The heat production efficiency of the multilateral horizontal well is significantly influenced by well depth and the arrangement of branch wells. Reservoir stimulation can effectively reduce flow impedance and improve the system economy. The multilateral horizontal well system is a promising development scheme for geothermal exploitation in Qiabuqia geothermal field. Full article

In recent years, rate of penetration (ROP) prediction using machine learning has attracted considerable interest. However, few studies have addressed ROP prediction uncertainty and its relation to training data and model inputs. This paper presents the application of a quantile regression deep neural network (QRDNN) for ROP prediction on multi-lateral wells drilled in the Alvheim field of the North Sea. The quantile regression framework allows the characterization of the prediction uncertainty, which can inform the end-user on whether the model predictions are reliable. Three different training strategies for the QRDNN model are investigated. The first strategy uses individual hole sections of the multi-lateral well to train the model, which is then tested on sections of similar hole size. In the second strategy, the models are trained for specific formations encountered in the well, assuming the formation tops are known for both the training and test sections. The third strategy uses training data from offset wells from the same field as the multi-lateral well, exploring different offset–well combinations and input features. The resulting QRDNN models are tested on several complete well sections excluded from the training data, each several kilometers long. The second and third strategies give the lowest mean absolute percentage errors of their median predictions of 27.3% and 28.7% respectively—all without recalibration for the unknown test well sections. Furthermore, the third model based on offset training gives a robust prediction of uncertainty with over 99.6% of actual values within the predicted P10 and P90 percentiles. Full article

The rapid growth of cities significantly impacts the development of transport and logistics infrastructure (TLI), creating substantial challenges for the transport network and quality of life. To enhance the efficiency and sustainability of TLI, various approaches, planning methods, and management strategies are employed at the city or agglomeration level. The objective of this study was to investigate, using graph theory and correlation analysis, the relationship between the polarity and logistic flow of the city’s meso-districts. Based on these findings, recommendations for the development of the city’s transport and logistics infrastructure were proposed. The logistic flow, influenced by social, economic, institutional, and environmental factors, plays a critical role in the planning and operation of transport and logistics infrastructure within each meso-district of the city. The determination of the polarity of meso-districts was conducted based on expert assessments by specialists, while the indicators of logistic flow were derived from the average values of statistical data for the period 2021–2023. The results demonstrated that a reduction in the polarity of meso-districts—characterized by multilateral connections between meso-districts and key indicators of logistic flows—can positively influence the quality and accessibility of the city’s transport and logistic infrastructure. This approach enables the identification of the most problematic meso-districts within the city, the mapping of logistic flow directions, and the determination of strategic development pathways for the city’s transport and logistics infrastructure (TLI). Furthermore, it was established that the polarity of the meso-district graph reflects the state of traffic congestion within the districts and its environmental impact. This correlation provides valuable insights into refining the planning and development of the city’s TLI, ensuring a more sustainable and efficient urban transport system. This study contributed to the development of the city’s transport and logistics infrastructure by proposing a comprehensive model that enhances the understanding and strengthens the interconnections between meso-districts and urban logistics. The findings hold significant implications for urban planning, as they highlight the necessity of a detailed consideration of the role of meso-districts, as well as targeted investments in transport and logistics infrastructure to ensure its sustainable development in the future. Full article

The teaching of human anatomy is experiencing significant transformation. Particularly in recent years, incorporating new digital technologies has drastically changed the approach to education. Our bibliometric study aims to investigate trends and issues from 2004 to 2024 related to digital technology in human anatomy teaching. The publication trend in the field has steadily increased over the years, peaking in 2022 and declining in 2023. Despite the limited statistics for 2024, we do not project an exponential increase in publications. Co-citation analysis identified notable references that significantly influenced the field, emphasizing modernization through innovative methodologies. Leading a significant portion of global collaboration, the United States promoted robust multilateral partnerships. Co-occurrence word analysis highlighted the merging of current technology with student-centered learning approaches, reflecting a shift towards more interactive and immersive learning experiences. Thematic map analysis identified distinct research areas with emerging or declining themes. The analysis of topic trends over the last five years revealed a persistent interest in terms like “palmar” and “carpal”, as well as innovative technologies like “cone beam computed tomography”, “augmented reality”, and “virtual reality”. Our bibliometric study revealed a sector in constant transformation, presenting a scenario where integrating technology with traditional teaching methods could enhance medical students’ comprehension of human anatomy. On the other hand, it also highlighted the anticipated challenges of ensuring equal access to cutting-edge technology, providing sufficient training for academic staff, and addressing emerging ethical issues. Full article

Based on the information of China’s bilateral energy diplomacy with 43 countries from 2000 to 2023, this study analyzes the impact of different diplomatic forms on China’s crude oil trade. A fixed-effects model is reconstructed to analyze the impact of various aspects of energy diplomacy on China’s crude oil trade based on panel data. These aspects include diplomacy frequency, frequency of visits, first or regular visits by heads of state, changes in diplomatic relationship levels, whether oil or energy is involved in joint public statements, and the nature of diplomacy (bilateral or multilateral). This study provides a reference for strategic decision-making in China’s energy diplomacy and indicates that frequent meetings of heads of state and proactive “going out” strategies in energy diplomacy significantly promote crude oil trade cooperation between two countries and ensure national energy security. Bilateral energy diplomacy is more effective in fostering crude oil trade cooperation with resource countries compared to multilateral diplomacy, with particularly notable effects in neighboring countries and those that belong to the Belt and Road Initiative (BRI). The Chinese government could increase the frequency of energy diplomacy, appropriately increase the frequency of overseas visits, and be more proactive in “going out” for energy diplomacy. There should be a greater focus on bilateral energy diplomacy with key resource countries, including neighboring countries such as Russia and Kazakhstan, as well as BRI countries such as Saudi Arabia, Iraq, the UAE, and Indonesia. It is also crucial to enhance the discourse power and influence of China in the global energy governance system. If the outcome documents of diplomatic activities involve crude oil or energy cooperation, they may invite competition from other resource countries or intervention from external forces. It is recommended that the principle of “do more, say less” is upheld. Any sensitive or controversial topics that would cause external interferences should be avoided, and not be included or actively mentioned. Based on practical cooperation with potential partner countries, the entire industry chain of energy investment, trade, technical services, and engineering equipment will be strengthened. Full article

Scaling up the direct use of geothermal heat in urban areas comes with the challenge of enabling the development of projects in geological settings where geothermal reservoir flow properties may be poor, resulting in low well flow performance. Cost-effective field development strategies and well designs tailored to such reservoirs can ensure the deliverability of geothermal energy in economic terms. This study presents a framework based on computer-assisted optimization to support practitioners in selecting the most suitable well concept for the exploitation of such marginal geothermal reservoirs. The proposed methodology is illustrated in a real-life case study of a geothermal development prospect in an urban area in The Netherlands, where the performance of sub-vertical, sub-horizontal and multi-lateral wells is compared. The obtained results indicate that the techno-economic performance of the geothermal doublet can be significantly improved by optimization, for all considered well concepts, and that, despite the importance of selecting the well concept, well location is still the main determinant of an effective field development strategy. The sub-horizontal and multi-lateral well concepts appear to be the most suitable for the target case study, outperforming the sub-vertical doublets, with a higher expected net present value and a lower economic variability risk for the multi-lateral solution. Full article

The adaptation finance gap is widening as the impact of climate change grows more disruptive around the globe. Although progress in adaptation planning and implementation has been observed across all sectors and regions, this trend of a widening resource gap calls for more ‘effective’ climate adaptation projects. Therefore, the purpose of this paper is to provide a comprehensive analysis to explore potential factors contributing to the effectiveness of climate change projects in developing countries with a particular focus on water management financed under multilateral funds that have been implemented on the ground, completed and documented. Thirty-five projects from the multilateral funds were collected and analyzed for this purpose. Project evaluation documents have been studied, and the effectiveness rating at completion has been assessed against possible contributing factors through regression analysis. The results showed that the factors contributing to project effectiveness converge around several elements: (i) capacity building and education (|r| > 0.3); (ii) healthy and resilient livelihoods (|r| > 0.2); and (iii) climate data and a robust theory of change (stated by >30% of projects). The implications from this study can provide a useful quantitative ground for discussion around the effective adaptation projects in water management as well as inform relevant international processes such as the Global Goal on Adaptation and global stocktake. Full article

Natural gas hydrates (NGHs) in the Shenhu area of the South China Sea are deposited in low-permeability clayey silt sediments. As a renewable energy source with such a low carbon emission, the exploitation and recovery rate of NGH make it difficult to meet industrial requirements using existing development strategies. Research into an economically rewarding method of gas hydrate development is important for sustainable energy development. Hydraulic fracturing is an effective stimulation technique to improve the fluid conductivity. In this paper, an efficient three-dimensional embedded discrete fracture model is developed to investigate the production simulation of hydraulically fractured gas hydrate reservoirs considering the stimulated reservoir volume (SRV). The proposed model is applied to a hydraulically fractured production evaluation of vertical wells, horizontal wells, and complex structural wells. To verify the feasibility of the method, three test cases are established for different well types as well as different fractures. The effects of fracture position, fracture conductivity, fracture half-length, and stimulated reservoir volume size on gas production are presented. The results show that the production enhancement in multi-stage fractured horizontal wells is obvious compared to that of vertical wells, while spiral multilateral wells are less sensitive to fractures due to the distribution of wellbore branches and perforation points. Appropriate stimulated reservoir volume size can obtain high gas production and production efficiency. Full article