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Sensing, Measurement & Data Analytics in the era of Artificial Intelligence (ICSMD), International Conference on

作者： Yu Guo Yong qin xuwen qin Ziliang Ren Lei Chen School of computer science and technology Dongguan University of Technology Dongguan China Grade A1 Shenzhen International Exchange College Shenzhen China

In multimodal sentiment analysis, heterogeneity between modalities makes inconsistent modal distributions a challenge. Especially in the case of incomplete features of certain modalities, the differences between modalities may interfere with the accurate prediction of sentiment categories. To address this problem, this paper proposes a missing modal reconstruction network (SSF-MMRN) for multimodal sentiment analysis based on sharing specific features. Firstly, a CMD distance-constrained training strategy is used to learn inter-modal consistency features. Second, based on the consistency features, a reconstruction module is proposed to generate missing modal features, check the semantic consistency of the recovered modalities with the original available modalities, and introduce inconsistencies into multiple models for better decision-making once they exist. Extensive experiments on the IEMOCAP benchmark dataset show that our proposed model effectively mitigates the modality gap during missing modality prediction and significantly improves the emotion recognition performance.

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Enhancing gas production and CO2 sequestration from marine hydrate reservoirs through optimized CO2 hydrate cap

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ENERGY 2024年 303卷

作者： Guo, Yang Li, Shuxia Sun, Hao Wu, Didi Liu, Lu Zhang, Ningtao qin, xuwen Lu, Cheng China Univ Petr East China State Key Lab Deep Oil & Gas Qingdao 266580 Peoples R China China Univ Petr East China Sch Petr Engn Qingdao 266580 Peoples R China East China Bur Sinopec Explorat & Dev Res Inst Nanjing 210019 Peoples R China China Geol Survey China Aero Geophys Survey & Remote Sensing Ctr Nat Beijing 100083 Peoples R China China Geol Survey Minist Nat Resources Oil & Gas Resources Survey Beijing 100083 Peoples R China

The invasion of formation water during marine hydrate production gravely affects gas productivity. CO2 hydrate caps effectively inhibit water invasion while sequestering CO2, which is considered an excellent prospective application. However, forming field -scale artificial CO2 hydrate caps remains a global challenge. This study proposed an innovative method for forming an artificial CO2 hydrate cap. The fracture length, injection time, production pressure, and production well distance, which are all factors that affect sealing capacity and production enhancement, were optimized. Results indicated that the sealing capacity exhibited a trend of initially increasing and subsequently decreasing with fracture length. The injection time was positively correlated with the sealing capacity and was sufficient to seal both vertically and horizontally once it reached 4 years. In addition to sequestering CO2, the CO2 hydrate cap enhanced gas production by 146.56 % and reduced water production by 37.47 % compared to direct depressurization. CO2 invasion occurred when the well spacing was too close, while being distant was not favorable for pressure propagation and heat utilization by the CO2 hydrate cap. This method simultaneously achieves multiple goals for energy and environmental, providing essential implications for the future commercial application of marine hydrates.

关键词： Gas hydrate CO2 hydrate cap Enhanced gas production CO2 sequestration Numerical simulation

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Enhanced strategies for depressurization in offshore natural gas hydrate exploitation: An in-depth investigation into pathway optimization and production stability mechanisms

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MARINE AND PETROLEUM GEOLOGY 2024年 170卷

作者： Li, Yuxuan Zhang, Zhaobin Li, Shouding He, Jianming Li, Xiao Xu, Tao Lu, Cheng qin, xuwen Chinese Acad Sci Key Lab Shale Gas & Geoengn Inst Geol & Geophys Beijing 100029 Peoples R China Chinese Acad Sci Innovat Acad Earth Sci Beijing 100029 Peoples R China Univ Chinese Acad Sci Coll Earth & Planetary Sci Beijing 100049 Peoples R China China Geol Survey Minist Nat Resources Oil & Gas Resources Survey Beijing 100083 Peoples R China China Geol Survey Minist Nat Resources China Ctr Aerial Geophys & Remote Sensing Nat Reso Beijing 100083 Peoples R China

Natural gas hydrates have garnered widespread attention as a high-quality energy resource. Recent offshore extraction experiences suggest that depressurization is a technically mature and economically viable option. However, challenges such as reservoir temperature reduction, reservoir subsidence, secondary hydrate formation, and insufficient dynamics in later-stage hydrate decomposition still require improvements to the depressurization method. This study, based on field data from Japan's first offshore natural gas hydrate extraction, utilizes a self-developed numerical simulator to model and validate reservoirs at the field scale. Long-term production rate stability, total production, secondary hydrate formation, reservoir subsidence, evolution of permeability, and temperature-pressure paths were analyzed and optimized for the three mainstream depressurization modes: steady depressurization, stepwise depressurization, and cyclic depressurization. The results indicate that, under the condition of equal total work done throughout the entire depressurization process, steady depressurization with an effectively lower depressurization rate is the optimal choice. Cyclic depressurization, due to the formation of secondary hydrates reducing the permeability of certain reservoir zones, adversely affects gas production efficiency during the long-term stable production phase. This study enhances insights into the coupled evolution of multiple physical fields during the depressurization of offshore natural gas hydrates, providing valuable guidance for future on-site extraction plan designs.

关键词： Natural gas hydrates Depressurization modes Numerical simulation Multiple physical fields On-site extraction plan

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Enhanced gas production from low-permeability hydrate reservoirs based on embedded discrete fracture models: Influence of branch parameters

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ENERGY 2023年第1期282卷

作者： Guo, Yang Li, Shuxia qin, xuwen Lu, Cheng Wu, Didi Liu, Lu Zhang, Ningtao China Univ Petr East China Key Lab Unconvent Oil & Gas Dev Minist Educ Qingdao 266580 Peoples R China China Univ Petr East China Sch Petr Engn Qingdao 266580 Peoples R China Minist Nat Resources China Geol Survey Beijing 100037 Peoples R China Minist Nat Resources China Geol Survey Oil & Gas Resources Survey Beijing 100083 Peoples R China East China Bur Sinopec Explorat & Dev Res Inst Nanjing 210019 Peoples R China

The low permeability of marine hydrate reservoirs makes it difficult for trail results to meet the demand for exploitation. Hydraulic fracturing and multi-branch wells are the primary methods for enhancing productivity. This study proposed a new production enhancement method of multi-branch wells combined with multi-stage fracturing (MWMF) based on the embedded discrete fracture model (EDFM). By simulation of the Shenhu area, the multi-physical field evolution of the MWMF production process was first revealed, followed by the systematic analysis of the MWMF production enhancement effect with branch parameters. Results indicated that the cumulative gas production of MWMF increased by 327% compared with only horizontal wells. The production of four-branch wells exhibited a 7% reduction compared to horizontal wells using the MWMF method, suggesting increased branch numbers inhibit production. Increasing branch length was positively correlated with enhanced production. Notably, the influence of branch length on gas production became more pronounced as the number of branches increased. The interface of the three-phase layer (TPL) and hydrate-bearing layer (HBL) was the most suitable location for branch well placement. This novel study provides valuable insights into new applications of the MWMF method in developing low-permeability hydrate reservoirs.

关键词： Natural gas hydrate Multi-branch well Multi-stage fracture Embedded discrete fracture model Enhanced gas production

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A password-authentication scheme based on ciphertext random sampling transmission

A password-authentication scheme based on ciphertext random ...

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IEEE International Symposium on Parallel and Distributed Processing with Applications and IEEE International Conference on Ubiquitous Computing and Communications (ISPA/IUCC)

作者： Lizhu Yang Yong qin xuwen qin Dongcheng Zhang School of Computer Science and Technology Dongguan University of Technology Dongguan China School of Cyberspace Security Dongguan University of Technology Dongguan China G2 Grade Shenzhen College of International Education Shenzhen China

The traditional identity authentication approach of username and password has the security risk of password leakage in the transmission process. For the security of password transmission in the blockchain education architecture, an asymmetric encryption algorithm is used to encrypt the transmitted password. Then use an improved random sampling algorithm to randomly extract part of the ciphertext and transmit those selected ciphertexts. The authentication credentials are sampled ciphertext and the location index. At the same time, the authentication factor is generated through the Time-Stamp technology, and mutual authentication is realized based on the Response-Challenge protocol. Through security analysis and experimental analysis, the proposed scheme is proved to be secure.

关键词： Protocols Education Authentication Focusing Passwords Ubiquitous computing Blockchains

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Research progress and scientific challenges in the depressurization exploitation mechanism of clayey-silt natural gas hydrates in the northern South China Sea

ADVANCES IN GEO-ENERGY RESEARCH

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ADVANCES IN GEO-ENERGY RESEARCH 2023年第1期10卷 14-20页

作者： Lu, Cheng qin, xuwen Sun, Jinsheng Wang, Ren Cai, Jianchao China Geol Survey Minist Nat Resources Oil & Gas Resources Survey Beijing 100083 Peoples R China Natl Engn Res Ctr Gas Hydrate Explorat & Dev Guangzhou 510075 Guangdong Peoples R China China Geol Survey China Aero Geophys Survey & Remote Sensing Ctr Na Beijing 100083 Peoples R China China Univ Petr East China Sch Petr Engn Qingdao 266580 Peoples R China CNPC Engn Technol R&D Co Ltd Beijing 102206 Peoples R China China Univ Petr Natl Key Lab Petr Resources & Engn Beijing 102249 Peoples R China

Natural gas hydrate reservoirs in the northern South China Sea primarily comprise clayey silt, making exploitation more challenging relative to sandy reservoirs in other countries and regions. This paper provides an overview of the latest research developments in the exploitation mechanism covering the past five years, focusing on hydrate phase transition, multiphase flow in the decomposition zone, the seepage regulation of reservoir stimulation zone, and production capacity simulation, all of which are relevant to the previously conducted two rounds of hydrate trial production in offshore areas of China. The results indicate that the phase transition of clayey-silt hydrate remains in a dynamic equilibrium, with the decomposition efficiency mainly controlled by the coupling of heat and flow and high heat consumption during decomposition. The decomposition zone exhibits strong hydrophilicity, easy adsorption, and sudden permeability changes. A temperature drop is present that is concentrated near the wellbore, and once a water lock has formed, the gas-phase flow capacity significantly decreases, leading to potential secondary hydrate formation. To enhance permeability and increase production, it is imperative to implement reservoir and temperature field reconstruction based on initial formation alterations, which will further optimize and improve the transport capacity of the reservoir.

关键词： Clayey-silt hydrate phase transition multiphase flow seepage regulation production simulation

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The impact of mineral compositions on hydrate morphology evolution and phase transition hysteresis in natural clayey silts

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ENERGY 2023年 274卷

作者： Bian, Hang qin, xuwen Sun, Jinsheng Luo, Wanjing Lu, Cheng Zhu, Jian Ma, Chao Zhou, Yingfang China Univ Geosci Sch Energy Resources Beijing 100083 Peoples R China China Geol Survey Ctr Oil & Nat Gas Resource Explorat Beijing 100083 Peoples R China China Geol Survey Beijing 100083 Peoples R China China Geol Survey Guangzhou Marine Geol Survey Guangzhou 510075 Peoples R China Natl Engn Res Ctr Gas Hydrate Explorat & Dev Guangzhou 511458 Peoples R China China Univ Petr East China Qingdao 266580 Peoples R China CNPC Engn Technol R&D Co Ltd Beijing 102206 Peoples R China iRock Technol Beijing 100094 Peoples R China Univ Aberdeen Sch Engn Aberdeen Scotland

Natural gas hydrate is a clean and high-efficient energy resource, and more than 90% of its reserves are con-tained in fine-grained (typically clayey silts) sediment. In this work, for the first time, the micro-scale imaging is performed to explore hydrate phase transition, morphology evolution and fundamental characteristics (mineral compositions, pore structures and seepage capacity) in clayey silt sediments. The results indicate that clayey silts formation properties strongly depend on dominant minerals component in the sediments. The clay-rich clayey silt possesses more microcapillary interstice with smaller permeability than that in quartz-rich sediment. Hy-drates generally occur as microfracture-filling (veins) and grain-displacing (nodulus) in sand-rich clayey silt. While they occur in the form of fracture-filling (vein) and foraminifera-filling in clay-rich clayey silt sediments. Biological fossils (especially foraminifera) provides potential space for hydrate aggregates. But hydrate formed inside it depends on the structures of fossils, the mineral components and pore structure of surrounding matrix. The hysteresis between hydrate formation and decomposition found to be more significant in clay-rich clayey silt sediment than quartz-rich sediment. And this hysteresis inside foraminifera is much more serious compared with that in matrix. In addition, dispersed pore-filling hydrates forms during decomposition, which has adverse effect on continuous gas production.

关键词： Clayey silt Hydrate phase transition Micro -scale properties Micro -scale imaging

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Potential triggers and development processes of submarine landslides in the Xisha Trough Basin, South China Sea

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GEOMORPHOLOGY 2024年 448卷

作者： Zhang, Yunshan Wu, Nan qin, xuwen Wu, Tingting Wei, Jiangong Wang, Pingkang Lv, Wenchao Jia, Yonggang Ocean Univ China Shandong Prov Key Lab Marine Environm & Geol Engn Qingdao Peoples R China China Geol Survey Zhoushan Field Sci Observat & Res Stn Marine Geoha Zhoushan Peoples R China Ocean Univ China Sanya Ocean Res Inst Sanya Hainan Peoples R China Tongji Univ State Key Lab Marine Geol Shanghai Peoples R China China Geol Survey Beijing Peoples R China Guangzhou Marine Geol Survey MLR Key Lab Marine Mineral Resources Guangzhou Peoples R China Guangzhou Marine Geol Survey Sanya Inst South China Sea Geol Sanya Peoples R China China Geol Survey Acad South China Sea Geol Sci Sanya Peoples R China Qingdao Natl Lab Marine Sci & Technol Lab Marine Geol Qingdao Shandong Peoples R China

Both submarine landslides and submarine canyons can transfer large amounts of terrigenous quantities from the continental shelf to the deep sea. In some cases, they can have a close relationship to their spatial distribution, formation and evolution. Submarine landslides on the shelf-slope can provide early depressions for submarine canyons, representing the early stage of submarine canyons. The continuous downcutting process during the evolution of submarine canyons can steepen the gradient of the canyon sidewalls, which can lead to the occurrence of submarine landslides. However, the role of submarine canyons in the initiation of slope failure has been overlooked. In this study, high-resolution multibeam bathymetry data, submarine image data and 2-D seismic data were used to investigate two adjacent submarine landslides developed on the northern slope of the Xisha Trough and the spatiotemporal relationship of these landslides to the Central Canyon. We identified a steep downslope between the submarine landslides and the Central Canyon. The Central Canyon formation age was much earlier than those of the submarine landslides. The Central Canyon is filled with modern submarine landslide deposits. The characteristics of the multiple failure scarps indicate retrogressive failure of the submarine landslides. We suggest that the submarine landslides developed on the northern slope of the Xisha Trough Basin have finally been captured by the Central Canyon. We determined that the emptying of sediments at the end of the northern slope of the Xisha Trough Basin caused by the development of the Central Canyon caused the end of the northern slope of the Xisha Trough Basin to lose support, which may have affected the slope stability and could have even played a role in the initiation of submarine landslides. Consequently, the slope area along the Central Canyon may be susceptible to slope instability and slope failure processes.

关键词： Submarine landslides Submarine canyons Retrogressive failure Xisha Trough Basin South China Sea

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Experimental Study on the Evolution of Hydrate Formation and Blockage in a Water-Dominated Bubbly Flow System

SSRN

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SSRN 2023年

作者： Kong, qingwen qin, xuwen Wang, Zhiyuan Zhang, Jianbo Tong, Shikun Sun, Baojiang Qingdao266580 China Department of Basic Investigation China Geological Survey Beijing100083 China National Engineering Research Center of Oil & Gas Drilling and Completion Technology Qingdao266580 China

During deepwater oil and gas drilling and hydrate production testing, water-dominated bubbly flow patterns may appear in the wellbore and drainage pipeline. Hydrate formation in bubbly flow may cause hydrate blockage and threaten the flow safety. In this study, a newly built high-pressure flow loop and a focused beam reflectance measurement device were used to investigate the evolution of hydrate formation and blockage in bubbly flow. The concentration and rate of hydrate rapid formation were mainly influenced by the initial flow velocity and maximum subcooling of the system. Considering the bubble breakage, coalescence and deformation, a kinetic model of hydrate rapid formation in bubbly flow was established based on the correction of the reaction rate factor K, and the model error was experimentally verified to be less than 15%. Hydrate aggregates in the range of 150–500 μm caused severe flow barriers, and three significant events were proposed to characterize the evolution degree of hydrate aggregation and blockage in bubbly flow. The critical initial flow velocity of 0.65±0.05 m/s determines whether hydrate aggregates with particle sizes larger than 150 μm will appear immediately when the hydrate is formed. And two main mechanisms of hydrate blockage in water-dominated bubbly flow were revealed. This study is expected to lay the foundation for hydrate flow assurance in wellbores and pipelines. © 2023, The Authors. All rights reserved.

关键词： Flow velocity

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Molecular simulation studies on the water/methane two-phase flow in a cylindrical silica nanopore: Formation mechanisms of water lock and implications for gas hydrate exploitation

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FUEL 2023年第Part1期333卷

作者： Zheng, Chao Guo, Guang-Jun qin, xuwen Dong, Yanhui Lu, Cheng Peng, Bo Tang, Wei Bian, Hang Chinese Acad Sci Inst Geol & Geophys Key Lab Petr Resource Res Beijing 100029 Peoples R China Univ Chinese Acad Sci Coll Earth & Planetary Sci Beijing 100049 Peoples R China China Geol Survey Guangzhou Marine Geol Survey Guangzhou 511458 Peoples R China Natl Engn Res Ctr Gas Hydrate Explorat & Dev Guangzhou 511458 Peoples R China Chinese Acad Sci Inst Geol & Geophys Key Lab Shale Gas & Geoengn Beijing 100029 Peoples R China China Geol Survey Ctr Oil & Nat Gas Resource Explorat Beijing 100083 Peoples R China China Univ Geosci Sch Energy Resources Beijing 100083 Peoples R China

The water/gas two-phase flow is a frequently encountered question in the percolation field, and is especially important for the exploitation of natural gas hydrates because their decomposition products are exactly liquid water and natural gas. We studied the water/methane two-phase flow in a hydrophilic cylindrical nanopore by performing molecular simulations, and obtained high-quality nanoflows under different water saturation (Sw) thanks to the newly established nano-manometer method to control pressure difference accurately. With increasing Sw, the methane flow decreases almost linearly until a sudden stop when Sw >= 0.52. The formation of the water lock accounting for this phenomenon is observed clearly, and the larger Sw, the earlier formation of the water lock as well as the longer water lock. Based on careful data analysis, a water lock model and its formation mechanism are newly proposed with two pieces of strong evidence - the continuous reduction of the surface area of the water/gas interface when the water lock forms and the existence of maximum thickness of water film for different Sw. Thus, the competition between the surface tension of the water/gas interface and the adsorption of the water/wall interface controls the development of the water lock. These findings are very helpful for un-derstanding the two-phase percolation and optimizing the gas production and water removal schemes during hydrate exploitation. In addition, the nano-manometer can be widely used in other nanoflow simulations for measuring the local pressure accurately.

关键词： Water methane two-phase flow Cylindrical nanopore Nano -manometer Relative permeability Water lock Natural gas hydrates

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