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A regression approach for seismic first-break picking

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Petroleum science 2024年第3期21卷 1584-1596页

作者： Huan Yuan san-Yi Yuan Jie Wu Wen-Jing sang Yu-He Zhao cnpc Key Laboratory of Geophysical Exploration China University of Petroleum (Beijing) Research Institute of Petroleum Exploration & Development—Northwest (NWGI) Key Laboratory of reservoir characterization of CNPCPetroChina

the picking efficiency of seismic first breaks(FBs) has been greatly accelerated by deep learning(DL)technology. However, the picking accuracy and efficiency of DL methods still face huge challenges in low signal-to-noise ratio(sNR) situations. to address this issue, we propose a regression approach to pick FBs based on bidirectional long short-term memory(Bi LstM) neural network by learning the implicit Eikonal equation of 3D inhomogeneous media with rugged topography in the target region. We employ a regressive model that represents the relationships among the elevation of shots, offset and the elevation of receivers with their seismic traveltime to predict the unknown FBs, from common-shot gathers with sparsely distributed traces. Different from image segmentation methods which automatically extract image features and classify FBs from seismic data, the proposed method can learn the inner relationship between field geometry and FBs. In addition, the predicted results by the regressive model are continuous values of FBs rather than the discrete ones of the binary distribution. the picking results of synthetic data shows that the proposed method has low dependence on label data, and can obtain reliable and similar predicted results using two types of label data with large differences. the picking results of9380 shots for 3D seismic data generated by vibroseis indicate that the proposed method can still accurately predict FBs in low sNR data. the subsequent stacked profiles further illustrate the reliability and effectiveness of the proposed method. the results of model data and field seismic data demonstrate that the proposed regression method is a robust first-break picker with high potential for field application.

关键词： First-break picking Low signal-to-noise ratio Regression BiLstM traveltime Geometry Noisy seismic data

Image Fusion Using Wavelet transformation and XGboost Algorithm

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Computers, Materials & Continua 2024年第4期79卷 801-817页

作者： shahid Naseem tariq Mahmood Amjad Rehman Khan Umer Farooq samra Nawazish Faten s.Alamri tanzila saba department of Information sciences Division of S&TUniversity of EducationLahore54770Pakistan Artificial Intelligence and Data Analytics(AIDA)Lab CCIS Prince Sultan UniversityRiyadh11586Saudi Arabia Faculty of Information sciences University of EducationVehari CampusVehari61100Pakistan department of Computer science University of Engineering and TechnologyTaxila47050Pakistan department of Mathematical sciences College of SciencePrincess Nourah Bint Abdulrahman UniversityRiyadh84428Saudi Arabia

Recently,there have been several uses for digital image processing.Image fusion has become a prominent application in the domain of imaging processing.to create one final image that provesmore informative and helpful compared to the original input images,image fusion merges two or more initial images of the same item.Image fusion aims to produce,enhance,and transform significant elements of the source images into combined images for the sake of human visual perception.Image fusion is commonly employed for feature extraction in smart robots,clinical imaging,audiovisual camera integration,manufacturing process monitoring,electronic circuit design,advanced device diagnostics,and intelligent assembly line robots,with image quality varying depending on application.the research paper presents various methods for merging images in spatial and frequency domains,including a blend of stable and curvelet transformations,everageMax-Min,weighted principal component analysis(PCA),HIs(Hue,Intensity,saturation),wavelet transform,discrete cosine transform(DCt),dual-tree Complex Wavelet transform(CWt),and multiple wavelet transform.Image fusion methods integrate data from several source images of an identical target,thereby enhancing information in an extremely efficient manner.More precisely,in imaging techniques,the depth of field constraint precludes images from focusing on every object,leading to the exclusion of certain characteristics.to tackle thess challanges,a very efficient multi-focus wavelet decomposition and recompositionmethod is proposed.the use of these wavelet decomposition and recomposition techniques enables this method to make use of existing optimized wavelet code and filter choice.the simulated outcomes provide evidence that the suggested approach initially extracts particular characteristics from images in order to accurately reflect the level of clarity portrayed in the original images.this study enhances the performance of the eXtreme Gradient Boosting(XGBoost)algorithm in detecting brain malignancies with

关键词： Image fusion max-min average CWt XGBoost DCt inclusive innovations spatial and frequency domain

Influence of Energy Policies on Development Path of Us Oil Companies

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China Oil & Gas 2024年第2期31卷 33-37页

作者： shi Wen cnpc International department

Focused on“energy security”,Us energy policies have undergone a multi-stage evolution.the main line has shifted from ensuring the oil and gas supply to achieving energy independence,and then to diversified development under a broader concept of energy security.the development path of Us oil and gas companies is guided and influenced by series of policies.Represented by ExxonMobil and Chevron,Us oil companies are maintaining a long commitment to the oil and gas business,especially unconventional resources such as shale gas and shale oil.Different from their European counterparts,Us oil companies have chosen CCs/CCUs as their primary method for achieving carbon neutrality.As for the new energy business,the Us oil giants are showing more interest in raw materials such as lithium resources rather than the power generation business.

关键词： companies shale independence

Production of chitosan-based composite film reinforced with lignin-rich lignocellulose nanofibers from rice husk

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Journal of Bioresources and Bioproducts 2024年第2期9卷 174-184页

作者： Hye Jee Kang Yeon Ju Lee Jin Kyoung Lee Irnia Nurika sri suhartini Deokyeong Choe Dong Hyun Kim Hoon Choi Natasha P.Murphy Ho Yong Kim Young Hoon Jung school of Food science and Biotechnology Kyungpook National UniversityDaegu 41566Republic of Korea CPR s&t Co. Ltd.Gunpo 15880Republic of Korea department of Agroindustrial technology Faculty of Agricultural TechnologyUniversitas BrawijayaMalang 65145Indonesia Renewable Resources and Enabling sciences Center National Renewable Energy LaboratoryGoldenCO 80401United States Center for Bio-based Chemistry Korea Research Institute of Chemical TechnologyUlsan 44429Republic of Korea

Lignocellulosic nanofibers(LCNFs),implying lignin-containing cellulose fibers,maintain the prop-erties of both lignin and cellulose,which are hydrophobic and hydrophilic,respectively.the pres-ence of hydrophobic lignin in LCNFs is expected to be an economical and attractive option that can improve the thermal and mechanical properties of polymers.thus,this study was conducted to produce lignin-rich LCNFs from sugar-rich waste obtained from rice husks after acidic pretreat-ment.the LCNFs were produced from the lignin-rich solid fractions obtained after pretreatment and enzymatic hydrolysis,which were then incorporated as an additive into a chitosan-based film.the variations in lignin content in the range of approximately 50.6%-66.8%in differently obtained LCNFs gave significantly different optical strengths and mechanical properties.these controllable processes may allow for customized film formation.Additionally,the glucose-rich liquid fractions obtained after pretreatment and enzymatic hydrolysis were used as a substrate for ethanol fermentation to achieve total utilization of rice husk biomass waste.In conclusion,the lignin-rich biomass fraction holds promise as a suitable material for chitosan-LCNF film and has the potential to increase the economic feasibility of the biomaterial industry.

关键词： Rice husk Lignocellulose nanofiber Lignin-based material Chitosan film Upcycling

Hyperbranched polymer hollow-fiber-composite membranes for pervaporation separation of aromatic/aliphatic hydrocarbon mixtures

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Chinese Journal of Chemical Engineering 2024年第5期69卷 13-22页

作者： tong Liu Hao sun Xiangqiong Wang Jie Li Zhanquan Zhang Pei Wu Naixin Wang Quanfu An Beijing Key Laboratory for Green Catalysis and separation Department of Chemical EngineeringCollege of Materials Science and EngineeringBeijing University of TechnologyBeijing 100124China Petrochemical Research Institute CNPCBeijing 102206China

the separation of aromatic/aliphatic hydrocarbon mixtures is crucial in the petrochemical industry.Pervaporation is regarded as a promising approach for the separation of aromatic compounds from alkanes. Developing membrane materials with efficient separation performance is still the main task since the membrane should provide chemical stability, high permeation flux, and selectivity. In this study, the hyperbranched polymer(HBP) was deposited on the outer surface of a polyvinylidene fluoride(PVDF)hollow-fiber ultrafiltration membrane by a facile dip-coating method. the dip-coating rate, HBP concentration, and thermal cross-linking temperature were regulated to optimize the membrane structure.the obtained HBP/PVDF hollow-fiber-composite membrane had a good separation performance for aromatic/aliphatic hydrocarbon mixtures. For the 50%/50%(mass) toluene/n-heptane mixture, the permeation flux of optimized composite membranes could reach 1766 g·m^(-2)·h^(-1), with a separation factor of 4.1 at 60℃. therefore, the HBP/PVDF hollow-fiber-composite membrane has great application prospects in the pervaporation separation of aromatic/aliphatic hydrocarbon mixtures.

关键词： Aromatic/aliphatic hydrocarbons Hyperbranched polymer Pervaporation Hollow fiber membrane Dip-coating

A seismic elastic moduli module for the measurements of low-frequency wave dispersion and attenuation of fluid-saturated rocks under different pressures

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Petroleum science 2024年第1期21卷 162-181页

作者： Yan-Xiao He shang-Xu Wang Gen-Yang tang Chao sun Hong-Bing Li san-Yi Yuan Xian Wei Li-Deng Gan Xiao-Feng Dai Qiang Ge Peng-Peng Wei Hui-Qing Zhang National Key Laboratory of Petroleum Resources and Engineering CNPC Key Lab of Geophysical ExplorationCollege of GeophysicsChina University of Petroleum(Beijing)Beijing102249China school of Resources and Geosciences China University of Mining and TechnologyXuzhou221116JiangsuChina Research Institute of Petroleum Exploration and Development CNPCBeijing100083China Beijing Vocational College of Labour and social security Beijing100029China PetroChina Dagang Oilfield Exploration and Development Research Institute CNPCTianjin300280China

Knowledge about the seismic elastic modulus dispersion,and associated attenuation,in fluid-saturated rocks is essential for better interpretation of seismic observations taken as part of hydrocarbon identification and time-lapse seismic surveillance of both conventional and unconventional reservoir and overburden performances.A seismic Elastic Moduli Module has been developed,based on the forced-oscillations method,to experimentally investigate the frequency dependence of Young's modulus and Poisson's ratio,as well as the inferred attenuation,of cylindrical samples under different confining pressure conditions.Calibration with three standard samples showed that the measured elastic moduli were consistent with the published data,indicating that the new apparatus can operate reliably over a wide frequency range of f∈[1-2000,10^(6)]Hz.the Young's modulus and Poisson's ratio of the shale and the tight sandstone samples were measured under axial stress oscillations to assess the frequency-and pressure-dependent effects.Under dry condition,both samples appear to be nearly frequency independent,with weak pressure dependence for the shale and significant pressure dependence for the sandstone.In particular,it was found that the tight sandstone with complex pore microstructure exhibited apparent dispersion and attenuation under brine or glycerin saturation conditions,the levels of which were strongly influenced by the increased effective pressure.In addition,the measured Young's moduli results were compared with the theoretical predictions from a scaled poroelastic model with a reasonably good agreement,revealing that the combined fluid flow mechanisms at both mesoscopic and microscopic scales possibly responsible for the measured dispersion.

关键词： Low-frequency measurements Dispersion and attenuation Rock physics Fluid flow

Changes in snow cover extent in the Central taurus Mountains from 1981 to 2021 in relation to temperature, precipitation, and atmospheric teleconnections

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Journal of Mountain science 2024年第1期21卷 49-67页

作者： Ecmel ERLAt Fulya AYDIN-KANDEMİR department of Geography Ege UniversityIzmir 35100Türkiye Climate Change and Zero Waste department Antalya Metropolitan MunicipalityAntalya 07310Türkiye Hydropolitics Association Ankara 06680Türkiye

the snow cover over the taurus Mountains affects water supply, agriculture, and hydropower generation in the region. In this study, we analyzed the monthly snow Cover Extent(sCE) from November to April in the Central taurus Mountains(Bolkar, Aladaglar, tahtali and Binboga Mountains) from 1981 to 2021. Linear trends of snow cover season(November to April) over the last 41 years showed decreases in sCE primarily at lower elevations. the downward trend in sCE was found to be more pronounced and statistically significant for only November and March. sCE in the Central taurus Mountains has declined about-6.3% per decade for 2500-3000 m in November and about-6.0% per decade for 1000-1500 m and 3000+ m in March over the last 41 years. the loss of sCE has become evident since the 2000s, and the lowest negative anomalies in sCE have been observed in 2014, 2001, and 2007 in the last 41 years, which are consistent with an increase in air temperature and decreased precipitation. sCE was correlated with both mean temperature and precipitation, with temperature having a greater relative importance at all elevated gradients. Results showed that there is a strong linear relationship between sCE and the mean air temperature(r =-0.80) and precipitation(r = 0.44) for all elevated gradients during the snow season. the Arctic Oscillation(AO), the North Atlantic Oscillation(NAO), and the Mediterranean Oscillation(MO) winter indices were used to explain the year-to-year variability in sCE over the Central taurus Mountains. the results showed that the inter-annual variability observed in the winter sCE on the Central taurus Mountains was positively correlated with the phases of the winter AO, NAO and MO, especially below 2000 m elevation.

关键词： snow cover extent Atmospheric teleconnection Central taurus Mountains Air temperature and precipitation Geographic Information systems türkiye

Liver transplantation as an alternative for the treatment of perihilar cholangiocarcinoma: A critical review

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Hepatobiliary & Pancreatic Diseases International 2024年第2期23卷 139-145页

作者： Wellington Andraus Francisco tustumi Alexandre Chagas santana Rafael soares Nunes Pinheiro Daniel Reis Waisberg Liliana Ducatti Lopes Rubens Macedo Arantes Vinicius Rocha santos Rodrigo Bronze de Martino Luiz Augusto Carneiro D’Albuquerque department of Gastroenterology Transplantation UnitUniversidade de São PauloSão PauloBrazil

Background:Perihilar cholangiocarcinoma(phCCC)is a dismal malignancy.there is no consensus regard-ing the best treatment for patients with unresectable phCCC.the present review aimed to gather the current pieces of evidence for liver transplantation and liver resection as a treatment for phCCC and to build better guidance for clinical practice.Data sources:the search was conducted in PubMed,Embase,Cochrane,and LILACs.the related references were searched manually.Inclusion criteria were:reports in English or Portuguese literature that a)patients with confirmed diagnosis of phCCC;b)patients treated with a curative intent;c)patients with the outcomes of liver resection and liver transplantation.Case reports,reviews,letters,editorials,conference abstracts and papers with full-text unavailability were excluded from the analysis.Results:Most of the current literature is based on observational retrospective studies with low grades of evidence.Liver resection has better long-term outcomes than systemic chemotherapy or palliation ther-apy and liver transplantation is a good alternative for selected patients with unresectable phCCC.All candidates for resection or transplantation should be medically fit and free of intrahepatic or extrahep-atic diseases.As a general rule,patients presenting with a tumor having a longitudinal size>3 cm or extending below the cystic duct,lymph node disease,confirmed extrahepatic dissemination;intraoper-atively diagnosed metastatic disease;a history of other malignancies within the last five years,and did not complete chemoradiation regimen and were medically unfit should not be considered for transplan-tation.some of these criteria should be individually assessed.Liver transplantation or resection should only be considered in highly experienced hepatobiliary centers,and any decision-making must be based on a multidisciplinary evaluation.Conclusions:phCCC is a complex condition with high morbidity.surgical therapies,including hepatec-tomy and liver transplantation,are the best option for bette

关键词： Liver transplantation Cholangiocarcinoma Liver neoplasms

simulation Method and Feature Analysis of shutdown Pressure Evolution During Multi-Cluster Fracturing stimulation

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Energy Engineering 2024年第1期121卷 111-123页

作者： Huaiyin He Longqing Zou Yanchao Li Yixuan Wang Junxiang Li Huan Wen Bei Chang Lijun Liu shale Gas Exploration and Development department CNPC Chuanqing Drilling Engineering Co.Ltd.Chengdu610051China College of Energy Chengdu University of TechnologyChengdu610059China

Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs,but the interpretation of hydraulic fracture parameters is challenging.the pressure signals after pump shutdown are influenced by hydraulic fractures,which can reflect the geometric features of hydraulic fracture.the shutdown pressure can be used to interpret the hydraulic fracture parameters in a real-time and cost-effective manner.In this paper,a mathematical model for shutdown pressure evolution is developed considering the effects of wellbore friction,perforation friction and fluid loss in fractures.An efficient numerical simulation method is established by using the method of characteristics.Based on this method,the impacts of fracture half-length,fracture height,opened cluster and perforation number,and filtration coefficient on the evolution of shutdown pressure are analyzed.the results indicate that a larger fracture half-length may hasten the decay of shutdown pressure,while a larger fracture height can slow down the decay of shutdown pressure.A smaller number of opened clusters and perforations can significantly increase the perforation friction and decrease the overall level of shutdown pressure.A larger filtration coefficient may accelerate the fluid filtration in the fracture and hasten the drop of the shutdown pressure.the simulation method of shutdown pressure,as well as the analysis results,has important implications for the interpretation of hydraulic fracture parameters.

关键词： Multistage multi-cluster hydraulic fracturing pump shutdown pressure feature analysis numerical simulation