Petroleum Science最新文献

{"title":"Effects of organic-inorganic transformation and interaction on the occurrence of nanopores within the organic-rich shale during thermal maturation: Insights from the hydrous pyrolysis experiments in a closed system","authors":"Yong Tang ,&nbsp;Chu-Xiong Li ,&nbsp;Hong Cheng ,&nbsp;Su-Yang Cai ,&nbsp;Xiao Li ,&nbsp;Qi-Lin Xiao ,&nbsp;Meng-Lin Zheng ,&nbsp;Jin Pan","doi":"10.1016/j.petsci.2025.02.024","DOIUrl":"10.1016/j.petsci.2025.02.024","url":null,"abstract":"<div><div>The organic-inorganic transformation and interaction act as the critical role in the occurrence of nanopores within the organic-rich shales during thermal maturation. Hydrous pyrolysis experiments were conducted on the organic-rich mudrock collected from the Upper Cretaceous Nenjiang Formation of the Songliao Basin, China in a closed system. The pore types and pore network, and organic and inorganic compositions of pyrolyzed shales were detected from the early to over mature stages (%<em>R</em>_o = 0.61–4.01). The experimental results indicate that geochemical transformation of organic matters and minerals and the interaction control the formation and evolution of nanoporosity. In oil window mineral matrix pores are infilled by the generated oil, K-feldspar dissolution by organic acids promotes clay illitization to form illite, and the catalytic effects of clays (e.g. illite) in the complex of organic matter and clays may promote the in-situ retained oil cracking to generate natural gas, resulting in the early occurrence of organic-matter pores in the complex within oil window. Due to significant primary cracking of solid kerogen to generate extractable liquid oil, pore volume for storing fluids presents a persistent increase and approaches the maximum at the end of oil window. In gas window intensive oil cracking facilitates the hydrocarbon migrating out of the source home and pyrobitumen formation, resulting in the significant occurrence of modified mineral matrix pores and organic-matter pores. Pore volume for hosting hydrocarbons presents a slight decrease at %<em>R</em>_o = 1.36–2.47 due to pyrobitumen formation by oil secondary cracking. The organic-inorganic interaction favors clay illitization, quartz dissolution, and pyrite and carbonate decomposition, which facilitate the occurrence of nanoporosity. Pyrobitumen within the complex with illite and organic matters are much more porous than that hosted in modified mineral matrix pores and microfractures. The catalytic effects of clays are supposed to be responsible for this. This study improves our understanding of the formation and evolution pathways of nanoporosity and the underlying controls in organic-rich shales during thermal maturation, and hence should be helpful in evaluating the sweet spots for shale-oil and shale-gas plays in a sedimentary basin.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 5","pages":"Pages 1823-1838"},"PeriodicalIF":6.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrocarbon generation reaction kinetics study on supercritical water conversion of centimeter sized medium and low maturity organic-rich shale","authors":"Tian Xie ,&nbsp;Qiu-Yang Zhao ,&nbsp;Hui Jin ,&nbsp;Ye-Chun Wang ,&nbsp;Lie-Jin Guo","doi":"10.1016/j.petsci.2025.02.020","DOIUrl":"10.1016/j.petsci.2025.02.020","url":null,"abstract":"<div><div>Accurate prediction of the composition of pyrolysis products is the prerequisite for achieving directional regulation of organic-rich shale pyrolysis and conversion products. In this paper, the classical segmented pyrolysis kinetics model and a new refined pyrolysis kinetics model were used to forecast the composition distribution of hydrocarbon generation products co-heated by supercritical water and medium and low maturity organic-rich shale. The prediction accuracy of the two reaction kinetics models for the composition of pyrolysis products of organic-rich shale was compared. The reaction path of hydrocarbon generation in centimeter sized organic-rich shale under the action of supercritical water was identified. The results show that the prediction accuracy of the classical segmented pyrolysis kinetics model was poor at the initial stage of the reaction, and gradually increased with increasing time. The prediction error can reach less than 25% when the reaction time was 12 h. The new refined model of reaction kinetics established is better than the classical reaction kinetics model in predicting the product distribution of pyrolysis oil and gas, and its prediction error is less than 14% in this paper. The reaction paths of hydrocarbon generation in centimeter sized organic-rich shale under supercritical water conversion mainly include organic-rich shale directly generates asphaltene and saturated hydrocarbon, asphaltene pyrolysis generates saturated hydrocarbon, aromatic hydrocarbon and resin, saturated hydrocarbon, aromatic hydrocarbon and resin polymerization generates asphaltene, and saturated hydrocarbon, resin and asphaltene generates gas. The reason for the difference of centimeter sized and millimeter sized medium and low maturity organic-rich shales hydrocarbon generation in supercritical water is that the increase of shale size promotes the reaction path of polymerization of saturated hydrocarbon and aromatic hydrocarbon to asphaltene.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 5","pages":"Pages 2203-2214"},"PeriodicalIF":6.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TOC","authors":"","doi":"10.1016/S1995-8226(25)00172-4","DOIUrl":"10.1016/S1995-8226(25)00172-4","url":null,"abstract":"","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 5","pages":"Pages i-ii"},"PeriodicalIF":6.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlating the carbonic acid reaction with tight sand and pure minerals during geological carbon storage","authors":"Yong-Peng Sun ,&nbsp;Guo-Liang Li ,&nbsp;Si-Zhe Zeng ,&nbsp;Jia-Wei Liu ,&nbsp;Xian-Fei Du ,&nbsp;Cai-Li Dai","doi":"10.1016/j.petsci.2025.03.045","DOIUrl":"10.1016/j.petsci.2025.03.045","url":null,"abstract":"<div><div>CO₂ injection into geological formations has been proven to be an effective approach for carbon storage. When dissolved in formation water, CO₂ forms carbonic acid that induces mineral dissolution at pore surfaces under acidic conditions. Comprehensive understanding of geochemical interaction between carbonic acid and reservoir rocks is crucial for assessing environmental impact on geological formations. This study focuses on a tight oil sandstone reservoir. After characterizing basic petrophysical properties and mineral composition of rock samples, a series of carbonic acid corrosion experiments with both core and corresponding pure mineral samples were carried out, respectively. Dissolution solutions collected during the experiments were analyzed to examine the variations of ion concentrations in both core and pure mineral solutions. The carbonic acid–pure mineral corrosion kinetics were investigated. The correlations between carbonic acid with core and pure mineral corrosion scenarios were established from the sample mass, reaction rate, and ion concentration. The results show that after corrosion, the mass of calcite and dolomite in the rock sample decreased by 66.7% and 27.3%, respectively. When the corrosion was stabilized, the concentrations of Ca²⁺ and Mg²⁺ in the core solution were 72.9 and 74.4 mg/L, respectively, which was 40.5–41.3 times higher than that of Na⁺. The reaction kinetics analysis of carbonic acid–rock revealed a two-stage reaction in the pure mineral corrosion process, rapid reaction stage, and slow reaction stage, with different reaction rate constants and reaction orders for each ion. With the correlation between carbonic acid reaction with core and pure minerals, an effective and rapid evaluation method with pure minerals for the carbonic water–rock reaction is established, which costs a shorter time and is easier to investigate. This study provides a simple and faster method to evaluate the carbonic acid corrosion reaction during geological carbon storage.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 5","pages":"Pages 2142-2153"},"PeriodicalIF":6.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of plunger lift working systems using reinforcement learning for coupled wellbore/reservoir","authors":"Zhi-Sheng Xing ,&nbsp;Guo-Qing Han ,&nbsp;You-Liang Jia ,&nbsp;Wei Tian ,&nbsp;Hang-Fei Gong ,&nbsp;Wen-Bo Jiang ,&nbsp;Pei-Dong Mai ,&nbsp;Xing-Yuan Liang","doi":"10.1016/j.petsci.2025.03.009","DOIUrl":"10.1016/j.petsci.2025.03.009","url":null,"abstract":"<div><div>In the mid-to-late stages of gas reservoir development, liquid loading in gas wells becomes a common challenge. Plunger lift, as an intermittent production technique, is widely used for deliquification in gas wells. With the advancement of big data and artificial intelligence, the future of oil and gas field development is trending towards intelligent, unmanned, and automated operations. Currently, the optimization of plunger lift working systems is primarily based on expert experience and manual control, focusing mainly on the success of the plunger lift without adequately considering the impact of different working systems on gas production. Additionally, liquid loading in gas wells is a dynamic process, and the intermittent nature of plunger lift requires accurate modeling; using constant inflow dynamics to describe reservoir flow introduces significant errors. To address these challenges, this study establishes a coupled wellbore–reservoir model for plunger lift wells and validates the computational wellhead pressure results against field measurements. Building on this model, a novel optimization control algorithm based on the deep deterministic policy gradient (DDPG) framework is proposed. The algorithm aims to optimize plunger lift working systems to balance overall reservoir pressure, stabilize gas–water ratios, and maximize gas production. Through simulation experiments in three different production optimization scenarios, the effectiveness of reinforcement learning algorithms (including RL, PPO, DQN, and the proposed DDPG) and traditional optimization algorithms (including GA, PSO, and Bayesian optimization) in enhancing production efficiency is compared. The results demonstrate that the coupled model provides highly accurate calculations and can precisely describe the transient production of wellbore and gas reservoir systems. The proposed DDPG algorithm achieves the highest reward value during training with minimal error, leading to a potential increase in cumulative gas production by up to 5% and cumulative liquid production by 252%. The DDPG algorithm exhibits robustness across different optimization scenarios, showcasing excellent adaptability and generalization capabilities.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 5","pages":"Pages 2154-2168"},"PeriodicalIF":6.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolution of multi-cluster fracturing in high-density layered shale considering the effect of injection scheme","authors":"Xiao Yan ,&nbsp;Haitao Yu ,&nbsp;Peng Zhang","doi":"10.1016/j.petsci.2025.03.008","DOIUrl":"10.1016/j.petsci.2025.03.008","url":null,"abstract":"<div><div>Shale oil reservoir is generally characterized by well-developed bedding planes, and multi-cluster fracturing is the most effective technique to achieve stable shale oil production. In this paper, a multi-cluster fracturing model for a horizontal well in shale with high-density bedding planes is established. The fracture morphology, fracture geometry, fracturing area and multiple fracture propagation mechanism are analyzed under simultaneous fracturing, sequential fracturing, and alternative fracturing. Results show that in the case of small cluster spacing and three clusters, the growth of the middle fracture is inhibited and develops along the bedding planes under both simultaneous fracturing and alternative fracturing. For sequential fracturing, the increase in the interval time between each fracturing advances the post fracturing fracture deflecting to the pre-existing fractures through the bedding planes. The reactivation of the bedding planes can promote the extension of the fracturing area. Increasing the injection rate and the number of clusters promotes the activation of bedding planes. However, it is preferable to reduce the number of clusters to obtain more main fractures. Compared with modified alternating fracturing and cyclic alternating fracturing, alternating shut-in fracturing creates more main fractures towards the direction of the maximum in-situ stress. The fracturing efficiency for high-density layered shale is ranked as simultaneous fracturing &gt; alternative fracturing &gt; sequential fracturing.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 5","pages":"Pages 2109-2122"},"PeriodicalIF":6.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pore network modeling of gas–water two-phase flow in deformed multi-scale fracture-porous media","authors":"Dai-Gang Wang ,&nbsp;Yu-Shan Ma ,&nbsp;Zhe Hu ,&nbsp;Tong Wu ,&nbsp;Ji-Rui Hou ,&nbsp;Zhen-Chang Jiang ,&nbsp;Xin-Xuan Qi ,&nbsp;Kao-Ping Song ,&nbsp;Fang-Zhou Liu","doi":"10.1016/j.petsci.2025.03.030","DOIUrl":"10.1016/j.petsci.2025.03.030","url":null,"abstract":"<div><div>Two actual rocks drilled from a typical ultra-deep hydrocarbon reservoir in the Tarim Basin are selected to conduct in-situ stress-loading micro-focus CT scanning experiments. The gray images of rock microstructure at different stress loading stages are obtained. The U-Net fully convolutional neural network is utilized to achieve fine semantic segmentation of rock skeleton, pore space, and micro-fractures based on CT slice images of deep rocks. The three-dimensional digital rock models of deformed multiscale fractured-porous media at different stress loading stages are thereafter reconstructed, and the equivalent fracture-pore network models are finally extracted to explore the underlying mechanisms of gas–water two-phase flow at the pore-scale. Results indicate that, in the process of in-situ stress loading, both the deep rocks have experienced three stages: linear elastic deformation, nonlinear plastic deformation, and shear failure. The micro-mechanical behavior greatly affects the dynamic deformation of rock microstructure and gas–water two-phase flow. In the linear elastic deformation stage, with the increase in in-situ stress, both the deep rocks are gradually compacted, leading to decreases in average pore radius, pore throat ratio, tortuosity, and water-phase relative permeability, while the coordination number nearly remains unchanged. In the plastic deformation stage, the synergistic influence of rock compaction and existence of micro-fractures typically exert a great effect on pore-throat topological properties and gas–water relative permeability. In the shear failure stage, due to the generation and propagation of micro-fractures inside the deep rock, the topological connectivity becomes better, fluid flow paths increase, and flow conductivity is promoted, thus leading to sharp increases in average pore radius and coordination number, rapid decreases in pore throat ratio and tortuosity, as well as remarkable improvement in relative permeability of gas phase and water phase.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 5","pages":"Pages 2096-2108"},"PeriodicalIF":6.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sequence stratigraphy and sedimentary evolution from Late Cretaceous to Quaternary in the Romney 3D seismic area, deep-water Taranaki Basin (New Zealand)","authors":"Guang-Xu Wang ,&nbsp;Wei Wu ,&nbsp;Quan Li ,&nbsp;Wei-Qing Liu ,&nbsp;Yong-Sheng Zhou ,&nbsp;Shi-Qin Liang ,&nbsp;Ya-Ping Sui","doi":"10.1016/j.petsci.2025.03.007","DOIUrl":"10.1016/j.petsci.2025.03.007","url":null,"abstract":"<div><div>The study of sequence stratigraphy often focuses on shallow marine and shelf-edge regions, while research on deep-sea stratigraphic sequences remains relatively weak. This study, based on high-resolution 3D seismic data and drilling information, utilized sequence stratigraphy and seismic sedimentology as guidelines, and employed seismic interpretation methods to performed a division of deep-sea stratigraphic sequences within the Romney 3D seismic survey area in the deep-water Taranaki Basin, New Zealand. Furthermore, it analyzed the characteristics of typical depositional systems and their associated controlling factors. The findings are as follows: (1) Based on seismic reflection termination relationships and seismic facies characteristics, four second-order sequence boundaries and nine third-order sequence boundaries were identified, resulting in the delineation of three second-order sequences and twelve third-order sequences in the basin. (2) Five seismic facies were recognized, corresponding to five typical sedimentary bodies: mass transport deposits (MTDs), deep-water channel, levee deposits, deltaic deposits, and pelagic deposits. However, due to the relatively thin sedimentary thickness of carbonate sediments, the seismic facies characteristics of carbonate sediments cannot be discerned in seismic data, but can be identified based on well data. Deltaic sediments mainly developed during the rift stage of the basin, while carbonate sediments formed during the transition from a passive to an active margin. Deep-water channel and levee deposits and MTDs emerged during the active margin stage, while pelagic deposits are ubiquitous in marine environments. (3) The uplift of New Zealand's interior and climate-driven erosion caused the resurgence of clastic sediments, which began to be transported to the deep sea, the seafloor topography would directly affect the movement path of sediment gravity flow, and sediment supply can affect the development and evolution of sedimentary systems. (4) Event deposits boundaries, such as erosional scour surfaces formed by channels and unconformities created by MTDs, can serve as boundaries for the division of deep-water stratigraphic sequences. This study proposes a method for delineating deep-water stratigraphic sequences using event deposits, particularly suitable under conditions where the influence of relative sea-level changes on deep-water deposits is relatively weak. This research not only enhances the understanding of deep-water depositional sequences but also provides a reference for studies on the evolution of deep-water deposition and its controlling factors in research areas with similar geological backgrounds worldwide.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 5","pages":"Pages 1854-1875"},"PeriodicalIF":6.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and modeling investigation of zero net liquid flow in hilly terrain pipeline","authors":"Bo Huang ,&nbsp;Qiang Xu ,&nbsp;Ying-Jie Chang ,&nbsp;Ye-Qi Cao ,&nbsp;Hai-Yang Yu ,&nbsp;Yu-Wen Li ,&nbsp;Lie-Jin Guo","doi":"10.1016/j.petsci.2025.03.026","DOIUrl":"10.1016/j.petsci.2025.03.026","url":null,"abstract":"<div><div>Hilly terrain pipeline is a common form of pipeline in oil and gas storage and transportation industry. Due to the hilly terrain influence, the liquid at the elbow of the gathering pipeline is easy to flow back and accumulate to form slug flow, so it is necessary to remove the accumulated liquid by gas purging. In this paper, experiment is carried out in hilly terrain pipelines. Three flow patterns of stratified flow, slug flow and stratified entrained flow are observed. The process of gas purging accumulated liquid is divided into four stages, namely liquid accumulation, liquid rising, continuous outflow and tail outflow. At the same time, the flow pattern maps of each stage are drawn. The pressure drop signal is analyzed in time domain and frequency domain, and the contour map of pressure drop distribution is drawn. It is found that the ratio of range to average value can well distinguish the occurrence range of each flow pattern. Based on visualization, the transition process of slug flow to stratified flow and stratified entrained flow is studied, and the transition boundary prediction model is established. An image processing method is proposed to convert the image signal into a similarity curve, and PSD analysis is performed to calculate the slug frequency. The normal distribution is used to fit the slug frequency, and the predicted correlation is in good agreement with the experimental data.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 5","pages":"Pages 2183-2202"},"PeriodicalIF":6.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response characteristics of shear waves scattered by fractures with borehole observation system","authors":"Peng Liu ,&nbsp;Hua-Jun Fan ,&nbsp;Meng-Sheng Zhang ,&nbsp;Zhen Li ,&nbsp;Jing-Wei Jiang ,&nbsp;Yuan Gao ,&nbsp;Ke-Wen Wang","doi":"10.1016/j.petsci.2025.03.004","DOIUrl":"10.1016/j.petsci.2025.03.004","url":null,"abstract":"<div><div>Fractures play a crucial role in various fields such as hydrocarbon exploration, groundwater resources management, and earthquake research. The determination of fracture location and the estimation of parameters such as fracture length and dip angle are the focus of geophysical work. In borehole observation system, the short distance between fractures and detectors leads to weak attenuation of elastic wave energy, and high-frequency source makes it easier to identify small-scale fractures. Compared to traditional monopole logging methods, dipole logging method has advantage of exciting pure shear waves sensitive to fractures, so its application is becoming increasingly widespread. However, since the reflected shear waves and scattered shear waves of fractures correspond to different fracture properties, how to distinguish and analyze these two kinds of waves is crucial for accurately characterizing the fracture parameters. To address this issue, numerical simulation of wave responses by a single fracture near a borehole in rock formation is performed, and the generation mechanism and characteristics of shear waves scattered by fractures are investigated. It is found that when the dip angle of the fracture surpasses a critical threshold, the S-wave will propagate to both endpoints of the fracture and generate scattered S-waves, resulting in two distinct scattered wave packets on the received waveform. When the polarization direction of the acoustic source is parallel to the strike of the fracture, the scattered SH-waves always have larger amplitude than the scattered SV-waves regardless of changing the fracture dip angle. Unlike SV-waves, the SH-waves scattered by the fracture do not have any mode conversion. Additionally, propagation of S-waves to a short length fracture can induce dipole mode vibration of the fracture within a wide frequency range. The phenomena of shear waves reflected and scattered by the fracture are further illustrated and verified by two field examples, thus showing the potential of scattered waves for fracture evaluation and characterization with borehole observation system.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 5","pages":"Pages 1912-1928"},"PeriodicalIF":6.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}