Petroleum Science最新文献

{"title":"Evaluation of dynamic inter-well connectivity by using the state-variable-capacitance model","authors":"Li-Wen Guo ,&nbsp;Shi-Yuan Qu ,&nbsp;Yuan-Yuan Lei ,&nbsp;Zhi-Hong Kang ,&nbsp;Shuo-Liang Wang","doi":"10.1016/j.petsci.2025.05.009","DOIUrl":"10.1016/j.petsci.2025.05.009","url":null,"abstract":"<div><div>During oilfield development, a comprehensive model for assessing inter-well connectivity and connected volume within reservoirs is crucial. Traditional capacitance (TC) models, widely used in inter-well data analysis, face challenges when dealing with rapidly changing reservoir conditions over time. Additionally, TC models struggle with complex, random noise primarily caused by measurement errors in production and injection rates. To address these challenges, this study introduces a dynamic capacitance (SV-DC) model based on state variables. By integrating the extended Kalman filter (EKF) algorithm, the SV-DC model provides more flexible predictions of inter-well connectivity and time-lag efficiency compared to the TC model. The robustness of the SV-DC model is verified by comparing relative errors between preset and calculated values through Monte Carlo simulations. Sensitivity analysis was performed to compare the model performance with the benchmark, using the Qinhuangdao Oilfield as a case study. The results show that the SV-DC model accurately predicts water breakthrough times. Increases in the liquid production index and water cut in two typical wells indicate the development time of ineffective circulation channels, further confirming the accuracy and reliability of the model. The SV-DC model offers significant advantages in addressing complex, dynamic oilfield production scenarios and serves as a valuable tool for the efficient and precise planning and management of future oilfield developments.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 8","pages":"Pages 3380-3396"},"PeriodicalIF":6.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048246","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":"Occurrence state of lacustrine shale oil in the second member of the Paleogene Kongdian Formation, Cangdong Sag, Bohai Bay Basin","authors":"Zhi-Hao Wang ,&nbsp;Jian-Hua Zhao ,&nbsp;Xian-Zheng Zhao ,&nbsp;Ke-Yu Liu ,&nbsp;Xiu-Gang Pu ,&nbsp;Qin-Hong Hu ,&nbsp;Wen-Zhong Han ,&nbsp;Wei Zhang ,&nbsp;Zhan-Nan Shi","doi":"10.1016/j.petsci.2025.07.001","DOIUrl":"10.1016/j.petsci.2025.07.001","url":null,"abstract":"<div><div>Understanding the occurrence state of shale oil is crucial for the effective development of shale oil resources. Although the second member of the Kongdian Formation (Ek₂) is a key interval for lacustrine shale oil production in the Cangdong Sag, Bohai Bay Basin, the occurrence state and controlling factors of shale oil in this formation remain poorly understood. This study established a multi-step programmed pyrolysis, combined with a light hydrocarbon recovery scheme, to quantitatively characterize the shale oil in different occurrence states. An integrated approach utilizing Rock-Eval pyrolysis, pyrolysis-gas chromatography, and crude oil gas chromatography was employed. Factors influencing the shale oil occurrence state were analyzed from petrology and organic geochemistry perspectives. The study revealed significant variations of shale oil occurrence states within the Ek₂, attributed to differences in sedimentary organic matter, mineral compositions, sedimentary structures, and thermal maturity. Felsic laminae are the primary reservoir space for oil in laminated shales, and the frequent interbedding of felsic and organic-rich laminae facilitates the retention of free oil. The contents of free and adsorbed oil are primarily influenced by organic matter content and shale storage capacity, both of which exhibit distinct occurrence patterns. Based on the shale reservoir quality classification using the pyrolysis values of S_1-1 + S_1-2 and (S_1-1 + S_1-2) × 100/TOC, the Ek₂ shale demonstrates significant exploitation potential, with the first-level reservoirs comprising 66%, second-level reservoirs 11%, and third-level reservoirs 23%. These findings provide new insights into the geological accumulation and production of shale oil.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 8","pages":"Pages 3189-3206"},"PeriodicalIF":6.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048146","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":"Fast simulation of EM telemetry in vertical drilling: A semi-analytical finite-element method with virtual layering technique","authors":"Hao Liang ,&nbsp;Chang-Chun Yin ,&nbsp;Yang Su ,&nbsp;Yun-He Liu ,&nbsp;Jun Li ,&nbsp;Ruo-Yun Gao ,&nbsp;Li-Bao Wang","doi":"10.1016/j.petsci.2025.06.002","DOIUrl":"10.1016/j.petsci.2025.06.002","url":null,"abstract":"<div><div>The electromagnetic (EM) telemetry systems, employed for real-time data transmission from the borehole and the earth surface during drilling, are widely used in measurement-while-drilling (MWD) and logging-while-drilling (LWD). Several numerical methods, including the method of moments (MoM), the electric field integral equation (EFIE) method, and the finite-element (FE) method have been developed for the simulation of EM telemetry systems. The computational process of these methods is complicated and time-consuming. To solve this problem, we introduce an axisymmetric semi-analytical FE method (SAFEM) in the cylindrical coordinate system with the virtual layering technique for rapid simulation of EM telemetry in a layered earth. The proposed method divides the computational domain into a series of homogeneous layers. For each layer, only its cross-section is discretized, and a high-precision integration method based on Riccati equations is employed for the calculation of longitudinally homogeneous sections. The block-tridiagonal structure of the global coefficient matrix enables the use of the block Thomas algorithm, facilitating the efficient simulation of EM telemetry problems in layered media. After the theoretical development, we validate the accuracy and efficiency of our algorithm through a series of numerical experiments and comparisons with the Multiphysics modeling software COMSOL. We also discussed the impact of system parameters on EM telemetry signal and demonstrated the applicability of our method by testing it on a field dataset acquired from Dezhou, Shandong Province, China.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 8","pages":"Pages 3304-3314"},"PeriodicalIF":6.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048184","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":"Deep learning-assisted optimization for enhanced oil recovery and CO2 sequestration considering gas channeling constraints","authors":"Xin-Yu Zhuang ,&nbsp;Wen-Dong Wang ,&nbsp;Yu-Liang Su ,&nbsp;Zhen-Xue Dai ,&nbsp;Bi-Cheng Yan","doi":"10.1016/j.petsci.2025.04.028","DOIUrl":"10.1016/j.petsci.2025.04.028","url":null,"abstract":"<div><div>Carbon dioxide Enhanced Oil Recovery (CO₂-EOR) technology guarantees substantial underground CO₂ sequestration while simultaneously boosting the production capacity of subsurface hydrocarbons (oil and gas). However, unreasonable CO₂-EOR strategies, encompassing well placement and well control parameters, will lead to premature gas channeling in production wells, resulting in large amounts of CO₂ escape without any beneficial effect. Due to the lack of prediction and optimization tools that integrate complex geological and engineering information for the widely used CO₂-EOR technology in promising industries, it is imperative to conduct thorough process simulations and optimization evaluations of CO₂-EOR technology. In this paper, a novel optimization workflow that couples the AST-GraphTrans-based proxy model (Attention-based Spatio-temporal Graph Transformer) and multi-objective optimization algorithm MOPSO (Multi-objective Particle Swarm Optimization) is established to optimize CO₂-EOR strategies. The workflow consists of two outstanding components. The AST-GraphTrans-based proxy model is utilized to forecast the dynamics of CO₂ flooding and sequestration, which includes cumulative oil production, CO₂ sequestration volume, and CO₂ plume front. And the MOPSO algorithm is employed for achieving maximum oil production and maximum sequestration volume by coordinating well placement and well control parameters with the containment of gas channeling. By the collaborative coordination of the two aforementioned components, the AST-GraphTrans proxy-assisted optimization workflow overcomes the limitations of rapid optimization in CO₂-EOR technology, which cannot consider high-dimensional spatio-temporal information. The effectiveness of the proposed workflow is validated on a 2D synthetic model and a 3D field-scale reservoir model. The proposed workflow yields optimizations that lead to a significant increase in cumulative oil production by 87% and 49%, and CO₂ sequestration volume enhancement by 78% and 50% across various reservoirs. These findings underscore the superior stability and generalization capabilities of the AST-GraphTrans proxy-assisted framework. The contribution of this study is to provide a more efficient prediction and optimization tool that maximizes CO₂ sequestration and oil recovery while mitigating CO₂ gas channeling, thereby ensuring cleaner oil production.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 8","pages":"Pages 3397-3417"},"PeriodicalIF":6.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048248","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":"OFC","authors":"","doi":"10.1016/S1995-8226(25)00306-1","DOIUrl":"10.1016/S1995-8226(25)00306-1","url":null,"abstract":"","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 8","pages":"Page OFC"},"PeriodicalIF":6.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145043919","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":"Plugging mode of flaky lost circulation materials within fractures and mechanism to enhance pressure-bearing capacity for the plugging zone","authors":"Kun Guo ,&nbsp;Yi-Li Kang ,&nbsp;Cheng-Yuan Xu ,&nbsp;Chong Lin ,&nbsp;Ling-Jie Zhang ,&nbsp;Li-Jun You","doi":"10.1016/j.petsci.2025.06.014","DOIUrl":"10.1016/j.petsci.2025.06.014","url":null,"abstract":"<div><div>During drilling operations in deep fractured tight gas reservoirs, lost circulation of working fluid frequently occurs due to the formationʼs low pressure-bearing capacity. Adding lost circulation materials (LCMs) to drilling fluids is the most common method for controlling lost circulation. Among these, granular LCMs are widely used, but the application frequency of flaky LCMs has been increasing annually due to their unique morphology. However, the migration and plugging behavior of flaky LCMs within fractures, and the mechanisms enhancing the pressure-bearing capacity of the plugging zone are not well understood. Therefore, this study conducted visual plugging experiments and dynamic fracture plugging experiments to evaluate the plugging mode and pressure-bearing capacity of the plugging slurry with various particle sizes and concentrations of flaky LCMs. The experimental results demonstrate that the fracture plugging process can be divided into four stages: uniform flow stage of the plugging slurry, formation and development stage of the bridging area, formation and development stage of the plugging area, and pressure-bearing stage of the plugging zone. The inclusion of flaky LCMs notably reduces the duration of stages 1 and 2, while simultaneously increasing the proportion of the plugging zone and enhancing its surface porosity. Flaky LCMs reduce the effective fracture width through “interception” and “co-bridging” modes, thus improving plugging zone formation efficiency. Appropriate particle size and concentration of flaky LCMs increase the area and length of the plugging zone. This reduces the fracture width increment caused by injection pressure and enhances frictional force between the plugging zone and fracture surface, thereby improving the pressure-bearing capacity of the plugging zone. However, excessively high concentrations of flaky LCMs result in decreased structural stability of the plugging zone, and excessively large particle sizes increase the risk of plugging outside fracture inlet. The recommended concentration of flaky LCMs in the plugging slurry is 2%–3%, with a particle size 1.2 to 1.5 times that of the bridging granular LCMs and not exceeding twice the fracture width. This study provides a theoretical foundation for selecting LCMs and designing plugging formulations for field applications.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 8","pages":"Pages 3315-3332"},"PeriodicalIF":6.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048183","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-scale gas–water two-phase flow and relative permeability characteristics of disassociated hydrate reservoir","authors":"Yu-Xuan Xia ,&nbsp;Derek Elsworth ,&nbsp;Sai Xu ,&nbsp;Xuan-Zhe Xia ,&nbsp;Jian-Chao Cai ,&nbsp;Cheng Lu","doi":"10.1016/j.petsci.2025.04.030","DOIUrl":"10.1016/j.petsci.2025.04.030","url":null,"abstract":"<div><div>Clayey-silt natural gas hydrate reservoirs in the South China Sea exhibit loose and unconsolidated structures, heterogeneous pore structures, high clay mineral contents, and strong hydrophilicity. These characteristics complicate the gas–water two-phase flow process in porous media following hydrate decomposition, posing challenges for efficient development. This study examines the transport response of clayey-silt reservoir samples from the Shenhu area using gas–water two-phase flow experiments and CT scanning to explore changes in pore structure, gas–water distribution, and relative permeability under varying flow conditions. The results indicate that pore heterogeneity significantly influences flow characteristics. Gas preferentially displaces water in larger pores, forming fracture-like pores, which serve as preferential flow channels for gas migration. The preferential flow channels enhance gas-phase permeability up to 19 times that of the water phase when fluid pressures exceed total stresses. However, small pores retain liquid, leading to a high residual water saturation of 0.561. CT imaging reveals that these hydro-fractures improve gas permeability but also confine gas flow to specific channels. Pore network analysis shows that gas injection expands the pore-throat network, enhancing connectivity and forming fracture-like pores. Residual water remains trapped in smaller pores and throats, while structural changes, including new fractures, improve gas flow pathways and overall connectivity. Relative permeability curves demonstrate a narrow gas–water cocurrent-flow zone, a right-shifted iso-permeability point and high reservoir capillary pressure, indicating a strong \"water-blocking\" effect. The findings suggest that optimizing reservoir stimulation techniques to enhance fracture formation, reduce residual water saturation, and improve gas flow capacity is critical for efficient hydrate reservoir development.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 8","pages":"Pages 3344-3356"},"PeriodicalIF":6.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048253","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)00308-5","DOIUrl":"10.1016/S1995-8226(25)00308-5","url":null,"abstract":"","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 8","pages":"Pages i-ii"},"PeriodicalIF":6.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145043920","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":"The analysis of drill string dynamics for extra-deep wells based on successive over-relaxation node iteration method","authors":"Wen-Chang Wang ,&nbsp;He-Yuan Yang ,&nbsp;Da-Kun Luo ,&nbsp;Ming-Ming You ,&nbsp;Xing Zhou ,&nbsp;Feng Chen ,&nbsp;Qin-Feng Di","doi":"10.1016/j.petsci.2025.05.026","DOIUrl":"10.1016/j.petsci.2025.05.026","url":null,"abstract":"<div><div>The complex vibration directly affects the dynamic safety of drill string in ultra-deep wells and extra-deep wells. It is important to understand the dynamic characteristics of drill string to ensure the safety of drill string. Due to the super slenderness ratio of drill string, strong nonlinearity implied in dynamic analysis and the complex load environment, dynamic simulation of drill string faces great challenges. At present, many simulation methods have been developed to analyze drill string dynamics, and node iteration method is one of them. The node iteration method has a unique advantage in dealing with the contact characteristics between drill string and borehole wall, but its drawback is that the calculation consumes a considerable amount of time. This paper presents a dynamic simulation method of drilling string in extra-deep well based on successive over-relaxation node iterative method (SOR node iteration method). Through theoretical analysis and numerical examples, the correctness and validity of this method were verified, and the dynamics characteristics of drill string in extra-deep wells were calculated and analyzed. The results demonstrate that, in contrast to the conventional node iteration method, the SOR node iteration method can increase the computational efficiency by 48.2% while achieving comparable results. And the whirl trajectory of the extra-deep well drill string is extremely complicated, the maximum rotational speed downhole is approximately twice the rotational speed on the ground. The dynamic torque increases rapidly at the position of the bottom stabilizer, and the lateral vibration in the middle and lower parts of drill string is relatively intense.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 8","pages":"Pages 3293-3303"},"PeriodicalIF":6.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048185","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":"Catalyst deactivation model involving autocatalytic effect for the residue hydrotreating process","authors":"Zhong-Huo Deng,&nbsp;Rong Shi,&nbsp;Liang Ren,&nbsp;Xin-Peng Nie,&nbsp;Qiang Fang,&nbsp;Zhen Wang,&nbsp;Wei Han,&nbsp;Li-Shun Dai","doi":"10.1016/j.petsci.2025.04.031","DOIUrl":"10.1016/j.petsci.2025.04.031","url":null,"abstract":"<div><div>Autocatalysis from the by-product metal sulfides plays a critical role in the residual oil hydrotreating (RHT) process. However, it has not been considered to build the catalyst deactivation models, which probably is one important reason that the widely used S-type deactivation models are inaccurate in predicting some RHT processes' deactivation profiles. A three-stage catalyst deactivation model was first developed to fill this gap based on the mechanism inferred from the experimental and literature data. This model accounts for active site formation from by-product metal sulfides, deactivation due to active site coverage by coke formation and metal deposition, active site poisoning by highly-adsorbed species, active phase sintering, and diffusion resistance from the pore blockage at the same time, resulting in a function of dimensionless metals-on-catalyst. Then, the effectiveness of the proposed model was evaluated using the industrial data of an RHT unit and the experimental data from the literature, either in combination with reaction kinetics or independently. Results showed that RHT processes with clear autocatalytic effects may display different types of deactivation profiles from the traditional \"S\" shape. However, the proposed model was able to accurately track the entire deactivation curve of the RHT process and well predict the product properties. This approach yields valuable insights into the intricate autocatalytic effect that remarkably contributes to the performance modification of RHT catalysts. It is highly recommended that further research should be conducted on this topic, as it shows great potential to significantly advance catalyst and process development.</div></div>","PeriodicalId":19938,"journal":{"name":"Petroleum Science","volume":"22 8","pages":"Pages 3447-3460"},"PeriodicalIF":6.1,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048244","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}