Natural Gas Industry B最新文献

{"title":"A viscosity-soluble type biomimetic self-healing cement slurry system","authors":"Youzhi Zheng ,&nbsp;Chaoyi She ,&nbsp;Hongqiong Fu ,&nbsp;Xiaoyang Guo ,&nbsp;Yao Wang","doi":"10.1016/j.ngib.2023.11.004","DOIUrl":"10.1016/j.ngib.2023.11.004","url":null,"abstract":"<div><p>With the development of cementing slurry technology, cementing self-healing has become one of the most effective technologies to prevent and treat oil and gas channeling and improve long-term sealing capacity of cement sheath. To solve the technical problem of annulus oil and gas channeling caused by the long-term sealing failure of cement sheath, this paper researches and develops a kind of viscosity-soluble type biomimetic self-healing cement slurry system from the perspective of chemical biomimetics, based on the technical idea of “prevention before blocking”. Then, the engineering performance of this biomimetic self-healing cement slurry system and the mechanical property of self-healing set cement are evaluated respectively. In addition, the mechanical recovery capacity and permeability reducing rate of the self-healing set cement conserved with methane are evaluated by creating fractures through splitting. Finally, the healing mechanisms of the self-healing cement are analyzed by means of SEM microscopic test and infrared spectrography. And the following research results are obtained. First, the set cement has excellent mechanical property. When the compressive strength decreases by 15 %, the elastic modulus of set cement decreases by 41 %, showing good toughness to play the role of “first prevention”. Second, when meeting hydrocarbon, the damaged set cement is excited to generate a kind of viscosity-soluble type gelatinous ester substance, which re-bonds the skeleton of the set cement. When the self-healing set cement is conserved with methane, its compressive strength recovery rate is up to 94.5 %, bending strength recovery rate is 58.6 %, gas log permeability drops by 99 %, and liquid log permeability drops by 100 %, so as to realize “blocking later”. In conclusion, the viscosity-soluble type biomimetic self-healing cement slurry system can effectively achieve cementing integrity and long-term sealing integrity through self-healing after the damage of cement sheath, which provides a strong technical support for preventing the production safety hazard of sustained casing pressure in oil and gas wells and is beneficial to solve the technical problem of annulus oil and gas channeling caused by long-term sealing failure of cement sheath.</p></div>","PeriodicalId":37116,"journal":{"name":"Natural Gas Industry B","volume":"10 6","pages":"Pages 547-554"},"PeriodicalIF":3.3,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352854023000773/pdfft?md5=b23952016ac51190ee787788d12096ca&pid=1-s2.0-S2352854023000773-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138623319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Progress in and research direction of key technologies for normal-pressure shale gas exploration and development","authors":"Xipeng He ,&nbsp;Guisong He ,&nbsp;Yuqiao Gao ,&nbsp;Longsheng Zhang ,&nbsp;Qing He ,&nbsp;Peixian Zhang ,&nbsp;Wei Wang ,&nbsp;Xiaozhen Huang","doi":"10.1016/j.ngib.2023.11.003","DOIUrl":"10.1016/j.ngib.2023.11.003","url":null,"abstract":"&lt;div&gt;&lt;p&gt;Normal-pressure shale gas is an important object of shale gas reserves and production increase with broad resource prospects in China, but its large-scale benefit development is still confronted with technical bottlenecks. To promote the large-scale benefit development of normal-pressure shale gas, this paper systematically sorts out and summarizes the research achievements and technological progresses related to normal-pressure shale gas from the aspects of accumulation mechanism, enrichment theory, percolation mechanism, development technology, and low-cost engineering technology, and points out the difficulties and challenges to the benefit development of normal-pressure shale gas in the complex structure zones of southern China, by taking the shale gas in the Southeast Chongqing Area of the Sichuan Basin as the research object. In addition, the research direction of normal-pressure shale gas exploration and development is discussed in terms of sweet spot selection, development technology policy, low-cost drilling technology and high-efficiency fracturing technology. And the following research results are obtained. First, the accumulation mechanism of normal-pressure shale gas is clarified from the perspective of geological exploration theory; the hydrocarbon accumulation model of generation, expulsion, retention and accumulation is established; the enrichment theory of “three-factor controlling reservoir” is put forward; and the comprehensive sweetspot target evaluation system is formed. Second, as for development technology, the development technology policies of “multiple series of strata, variable well spacing, long horizontal section, small included angle, low elevation difference, strong stimulation and pressure difference controlling” are formulated. Third, as for drilling engineering, the optimal fast drilling and completion technology with “secondary structure + radical parameter + integrated guidance + unpressured leak-proof cementing” as the core is formed. Fourth, as for fracturing engineering, the low-cost and high-efficiency fracturing technology with “multi-cluster small-stage + limited-entry perforating + double temporary blocking + high-intensity sand injection + fully electric” as the core is formed. Fifth, normal-pressure shale gas is characterized by complex geological conditions, low pressure coefficient and gas content, poor resource endowment and so on, but its resource utilization still faces a series of challenges, such as uncertain productivity construction positions, low single-well productivity and ultimate recoverable reserve, high investment cost and poor economic benefit. In conclusion, the key research directions to realize the large-scale benefit development of low-grade normal-pressure shale gas are to deepen the research on the enrichment and high yield mechanism and sweet spot selection of normal-pressure shale gas, strengthen the research on the benefit development technology policy based on percola","PeriodicalId":37116,"journal":{"name":"Natural Gas Industry B","volume":"10 6","pages":"Pages 555-569"},"PeriodicalIF":3.3,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352854023000761/pdfft?md5=c54c6ff8945ba5a0bc6cd439c996e3bc&pid=1-s2.0-S2352854023000761-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138613580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of fracturing stages/clusters in horizontal well based on unsupervised clustering of bottomhole mechanical specific energy on the bit","authors":"Shimeng Hu ,&nbsp;Mao Sheng ,&nbsp;Shanzhi Shi ,&nbsp;Jiacheng Li ,&nbsp;Shouceng Tian ,&nbsp;Gensheng Li","doi":"10.1016/j.ngib.2023.11.002","DOIUrl":"10.1016/j.ngib.2023.11.002","url":null,"abstract":"<div><p>Multi-cluster perforation and multi-staged fracturing of horizontal well is one of the main technologies in volumetric fracturing stimulation of unconventional oil and gas reservoirs, but unconventional reservoirs in China are generally of strong heterogeneity, which causes different fracture initiation pressures in different positions of lateral, making it difficult to ensure the balanced fracture initiation and propagation between clusters in multi-cluster perforating. It is in urgent need to precisely evaluate the difference in rock strength in lateral and determine the well section with similar rock strength to deploy fractures, so as to reach the goal of balanced stimulation. Based on the drilling and logging data, this paper establishes an unsupervised clustering model of mechanical specific energy of bit at the bottomhole the lateral. Then, the influence of drill string friction, composite drilling and jet-assisted rock breaking on the mechanical specific energy is analyzed, and the distribution and clustering categories of bottomhole mechanical specific energy with decimeter spatial resolution are obtained. Finally, a fracture deployment optimization method for horizontal well volumetric fracturing aiming balanced stimulation is developed by comprehensively considering inter-fracture interference, casing collar position, plug position, and clustering result of bottomhole mechanical specific energy. The following results are obtained. First, compared with brittleness index, Poisson's ratio and stress difference, perforation erosion area is in a stronger correlation with the mechanical specific energy, and the mechanical specific energy can effectively characterize the difference in the amount of proppant injected into the perforation clusters in the lateral, so it can be served as one of the important indicators for the selection of fracture deployment position. Second, the drilling and logging data cleaning and smoothing and the clustering number selection by the elbow method are the key steps to obtain the clustering results of bottomhole mechanical specific energy, which can tell the difference in the mechanical specific energy with decimeter-level resolution. Third, the interval with mechanical specific energy within 10% of the average value in the section is selected for deploying perforation clusters, and the compiled computer algorithm can automatically determine the optimal position of fracturing section and cluster, so as to realize the differential design of stage spacing and cluster spacing. In conclusion, the research results can further improve the fractures deployment efficiency and balanced stimulation of volumetric fracturing in unconventional oil and gas reservoirs, and this technology is expected to provide ideas and new methods for the fracture deployment optimization of horizontal well volumetric fracturing in unconventional oil and gas reservoirs.</p></div>","PeriodicalId":37116,"journal":{"name":"Natural Gas Industry B","volume":"10 6","pages":"Pages 583-590"},"PeriodicalIF":3.3,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S235285402300075X/pdfft?md5=6800db44d5f5722e83c6fb2d2ae8721c&pid=1-s2.0-S235285402300075X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138622804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling underground coal gasification: What to start with","authors":"Liangliang Jiang ,&nbsp;Lele Feng ,&nbsp;Wu Gao ,&nbsp;Jin Sun ,&nbsp;Anqi Shen ,&nbsp;Jiang Liu ,&nbsp;Zixiang Wei ,&nbsp;Dan Xue ,&nbsp;Shanshan Chen ,&nbsp;Yanpeng Chen ,&nbsp;Zhangxin Chen ,&nbsp;S.M. Farouq Ali","doi":"10.1016/j.ngib.2023.11.006","DOIUrl":"10.1016/j.ngib.2023.11.006","url":null,"abstract":"<div><p>Underground coal gasification (UCG) is widely regarded as a clean coal technology that holds enormous potential to decarbonize the world's coal industry. It converts coal underground into combustible syngas through a set of complex physiochemical events. Experimental and numerical efforts over the past century have contributed to the development of UCG around the world; however, tapping the world's deep-situated coal resources with UCG requires substantial contributions from numerous high-quality researchers. To facilitate effective engagement, this paper will provide a background on where to start if one wishes to undertake UCG modelling. First, a brief description of the fundamental phenomena involved in UCG is given. Then, a succinct introduction of the widely used modelling software is rendered, followed by a description of UCG studies to provide insight how to tune the various software packages for modelling UCG and where their strengths lie. This paper shall serve as guidance to new UCG modellers.</p></div>","PeriodicalId":37116,"journal":{"name":"Natural Gas Industry B","volume":"10 6","pages":"Pages 626-637"},"PeriodicalIF":3.3,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352854023000797/pdfft?md5=83702b73bdd8bb93ee9466d9dcb69778&pid=1-s2.0-S2352854023000797-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138991407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the controlling effect of new annulus materials on casing deformation in shale gas wells","authors":"Fei Yin ,&nbsp;Pengju Ye ,&nbsp;Biaobin Shi ,&nbsp;Liu Yang ,&nbsp;Jingyuan Xu ,&nbsp;Yingjie Chen ,&nbsp;Hongquan Xia ,&nbsp;Leichuan Tan ,&nbsp;Chunquan Wang","doi":"10.1016/j.ngib.2023.11.009","DOIUrl":"10.1016/j.ngib.2023.11.009","url":null,"abstract":"<div><p>Shale gas horizontal wells have severe problems of casing deformation and failure due to formation displacement during fracturing. Statistics show that casing deformation problems occur frequently in the development of shale gas, especially in Sichuan Basin. Furthermore, the phenomenon of formation extrusion and fault slip is serious, which has caused great obstacles to the development of shale gas in China. In view of the current lack of casing deformation control methods, a finite element model of a wellbore under formation displacement load is established in this paper. The stress and deformation of the casing are simulated, and the mitigating effects of new annular materials such as a modified cement sheath and rubber are evaluated. Results indicate that the formation extrusion and fault slip can cause radial oval deformation and axial S-shaped deformation of the production casing, respectively. The use of a modified cement sheath can provide a little mitigating effect on casing deformation. Meanwhile, using rubber cementing can play a strong protective role for the production casing and avoid casing deformation to a certain extent. This research can provide a new way and important reference for the prevention and control of casing deformation in shale gas wells.</p></div>","PeriodicalId":37116,"journal":{"name":"Natural Gas Industry B","volume":"10 6","pages":"Pages 638-647"},"PeriodicalIF":3.3,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352854023000827/pdfft?md5=ae5d050e476c3b443a0a359244948e56&pid=1-s2.0-S2352854023000827-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139023078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Key technologies and orientation of EGR for the Sulige tight sandstone gas field in the Ordos Basin","authors":"Zheng Wu ,&nbsp;Qianfeng Jiang ,&nbsp;You Zhou ,&nbsp;Yaning He ,&nbsp;Yanyan Sun ,&nbsp;Wei Tian ,&nbsp;Changjing Zhou ,&nbsp;Weijie An","doi":"10.1016/j.ngib.2023.11.005","DOIUrl":"10.1016/j.ngib.2023.11.005","url":null,"abstract":"<div><p>The Sulige Gas Field in the Ordos Basin is the largest tight gas field in China, with proved reserves exceeding 2 × 10¹² m³. As the main contributor to gas production in PetroChina Changqing Oilfield Company, The Sulige Gas Field is in the stage of stable production. Maximizing the stable production period is a focus and challenge for the gas field now. To address a series of problems influencing the efficient development of Sulige gas field, such as large-scale remaining gas reserves between wells/layers and low ratio of employed reserves, the main technologies for enhanced gas recovery (EGR) of tight gas reservoirs were developed by multidisciplinary research with respect to development geology, reservoir engineering, drilling and production process, and surface gathering and transportation. Experiments were conducted on reservoir description and remaining gas characterization, well pattern thickening optimization, vertical well separate-layer fracturing, horizontal-well multi-stage multi-cluster volume fracturing for their improvement and upgrading. The orientation of EGR for tight gas reservoirs is proposed. The following results are obtained. First, well pattern thickening optimization is the most important EGR method, which can increase the recovery rate by more than 6%. Second, based on continuous upgrading and promotion, either of reservoir stimulation technology and drainage gas recovery technology can increase the recovery rate by more than 2%. The gathering and transportation technology which further reduces the wellhead pressure can increase the recovery rate by about 1.5%. Third, the EGR technology should be oriented to maximize the quantity of employed reserves, especially by way of new technologies such as fine remaining gas characterization, well pattern/type optimization, cross-layer fracturing of a multi-thin-layer reservoir by horizontal wells, intelligent drainage gas recovery, and multi-stage pressurization. It is concluded that the development of key EGR technologies will help increase the recovery rate of The Sulige Gas Field by 10%–15%, and will provide an effective support for The Sulige Gas Field to maintain the production at 300 × 10⁸ m³/a for a long term and for the Changqing gas province to increase the production to 500 × 10⁸ m³/a, which will ultimately ensure the national energy security.</p></div>","PeriodicalId":37116,"journal":{"name":"Natural Gas Industry B","volume":"10 6","pages":"Pages 591-601"},"PeriodicalIF":3.3,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352854023000785/pdfft?md5=93e31bc6988d73feba0ec0fc7dfe0af9&pid=1-s2.0-S2352854023000785-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138616428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brazilian splitting experiment and finite element simulation analysis of the influence of bedding loading angle on shale fracture mode","authors":"Yingkun Zhang ,&nbsp;Shangbin Chen ,&nbsp;Xiaohang Zhai ,&nbsp;Jamil Khan ,&nbsp;Yuhang Zhang","doi":"10.1016/j.ngib.2023.11.007","DOIUrl":"10.1016/j.ngib.2023.11.007","url":null,"abstract":"<div><p>During the diagenetic processes of compaction and cementation, shale forms multiple beddings, significantly effecting the rock anisotropy. Therefore, it is important to study the effect of bedding on the mechanical properties of shale to guide fracturing engineering. To study the failure mode and fracture morphology of shale with bedding planes under different bedding dip angles, Brazilian disc splitting tests and finite element numerical simulations are performed for shale samples and the results are compared. (1) The bedding angle has a significant effect on the failure mode and tensile strength of shale, and the tensile strength tends to increase with increasing bedding angle. (2) The failure modes of shale under different bedding dip angles can be divided into three types: tensile failure along the bedding plane; comprehensive shear and tensile failure of the matrix and the bedding plane; and matrix tensile failure. (3) The direction of secondary cracks is mostly perpendicular to the bedding plane, and a smaller angle between the load application direction and the bedding direction results in a larger number of generated cracks with more complex shapes. (4) When the loading angle of the bedding is 30°, the tensile strength is low and the matrix and the bedding plane are comprehensively destroyed by shear and tension, resulting in a more complex joint mesh; conversely, when the bedding angle is greater than 60°, the tensile strength increases and the complexity of the seam mesh decreases. These findings can provide guidance for the selection of the bedding angle and the design of fracturing schemes in fracturing engineering.</p></div>","PeriodicalId":37116,"journal":{"name":"Natural Gas Industry B","volume":"10 6","pages":"Pages 602-612"},"PeriodicalIF":3.3,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352854023000803/pdfft?md5=e81fd6a6a92b296631dd1cd5d2f3dae8&pid=1-s2.0-S2352854023000803-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139026394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pore-scale numerical simulation of supercritical CO2-brine two-phase flow based on VOF method","authors":"Yongfei Yang,&nbsp;Jinlei Wang,&nbsp;Jianzhong Wang,&nbsp;Qi Zhang,&nbsp;Jun Yao","doi":"10.1016/j.ngib.2023.08.002","DOIUrl":"https://doi.org/10.1016/j.ngib.2023.08.002","url":null,"abstract":"<div><p>CO₂ capture and storage technology is favorable for the reduction of CO₂ emissions. In recent years, a great number of research achievements have been obtained on CO₂ geological storage from nano scale to oil/gas reservoir scale, but most studies only focus on the flow behaviors in single-dimension porous media. Besides, the physical experiment method is influenced by many uncertain factors and consumes a lot of time and cost. In order to deeply understand the flow behaviors in the process of CO₂ geological storage in microscopic view and increase the volume of CO₂ geological storage, this paper established 2D and 3D models by using VOF (Volume of Fluid) method which can track the dynamic change of two-phase interface, to numerically simulate supercritical CO₂-brine two-phase flow. Then, the distribution characteristics of CO₂ clusters and the variation laws of CO₂ saturation under different wettability, capillary number and viscosity ratio conditions were compared, and the intrinsic mechanisms of CO₂ storage at pore scale were revealed. And the following research results were obtained. First, with the increase of rock wettability to CO₂, the sweep range of CO₂ enlarged, and the disconnection frequency of CO₂ clusters deceased, and thus the volume of CO₂ storage increased. Second, with the increase of capillary number, the displacement mode transformed from capillary fingering to stable displacement, and thus the volume of CO₂ storage increased. Third, as the viscosity of injected supercritical CO₂ gradually approached that of brine, the flow resistance between two-phase fluids decreased, promoting the \"lubricating effect\". As a result, the flow capacity of CO₂ phase was improved, and thus the volume of CO₂ storage was increased. Fourth, the influence degrees of wettability, capillary number and viscosity ratio on CO₂ saturation were different in multi-dimensional porous media models. In conclusion, the CO₂-brine two-phase flow simulation based on VOF method revealed the flow mechanisms in the process of CO₂ geological storage at pore scale, which is of guiding significance to the development of CCUS technology and provides theoretical guidance and technical support for the study of CO₂ geological storage in a larger scale.</p></div>","PeriodicalId":37116,"journal":{"name":"Natural Gas Industry B","volume":"10 5","pages":"Pages 466-475"},"PeriodicalIF":3.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71761115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation of oil and gas pipeline corrosion based on single- or coupled-factor modeling: A critical review","authors":"Chengtao Wang ,&nbsp;Mostafa Fahmi Hassanein ,&nbsp;Mengmeng Li","doi":"10.1016/j.ngib.2023.08.001","DOIUrl":"10.1016/j.ngib.2023.08.001","url":null,"abstract":"<div><p>Numerical simulation is an effective research approach to assess the condition and predict the remaining service life of process pipelines suffering corrosion hazards. This work comprises a critical review of 182 academic articles to analyze environmental factors affecting the pipeline corrosion process, basic numerical methods for corrosion simulation, and single- and coupled-factor numerical investigations. Numerical simulation of corroded pipelines could combine the electrochemical corrosion processes and structural characteristics of pipelines to obtain more accurate results. Multiphysics-based techniques have been successfully applied to simulate the evolution process of corroded pipelines affected by two or more coupled factors under stray current interference. Through integration with learning-based algorithms, predictive studies are conducted to assess the development of corrosion. The challenge for current research is that the remaining types of corrosion are difficult to describe by numerical methods. Opportunities are proposed to improve the pipeline corrosion simulation model to describe more corrosion types and realistic corrosion morphologies, including time-varying corrosion simulation, random field in the simulation, and microelectrochemical corrosion simulation.</p></div>","PeriodicalId":37116,"journal":{"name":"Natural Gas Industry B","volume":"10 5","pages":"Pages 445-465"},"PeriodicalIF":3.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47933685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal‒hydraulic‒mechanical‒chemical coupling analysis of enhanced geothermal systems based on an embedded discrete fracture model","authors":"Dongxu Han ,&nbsp;Weitao Zhang ,&nbsp;Kaituo Jiao ,&nbsp;Bo Yu ,&nbsp;Tingyu Li ,&nbsp;Liang Gong ,&nbsp;Shurong Wang","doi":"10.1016/j.ngib.2023.10.001","DOIUrl":"https://doi.org/10.1016/j.ngib.2023.10.001","url":null,"abstract":"<div><p>Enhanced geothermal system (EGS) is subject to the comprehensive effects of multiple physical fields during the long-term heat extraction process, including hydraulic (H), thermal (T), mechanical (M) and chemical (C) fields. The embedded discrete fracture model (EDFM) can effectively simulate the variations of flow, temperature, mechanical and concentration fields in fractured reservoirs. At present, however, the thermo-hydro-mechanical-chemical (THMC) coupling model based on EDFM is less researched. In this paper, the THMC coupling model of fractured reservoir is established based on EDFM by considering the changes in reservoir heterogeneity and physical properties as well as water–rock reactions. Then, the spatiotemporal evolution of flow, temperature, displacement and concentration fields in the operation process of EGS is simulated and analyzed. And the following research results are obtained. First, when the permeability of the basement rock is low, the production temperature decrease during exploitation is gradual, allowing EGS to maintain a high exploitation temperature for an extended period. However, lower permeability may result in a decrease in the quality flow rate from production wells, thereby affecting net heat extraction power. Second, when fracture permeability or fracture opening changes, EGS can output higher temperature stably for a certain period and then the temperature decreases at different amplitudes. When the fracture permeability increases to a certain value or the fracture opening decreases to a certain value, the influence of the change in fracture parameters on production temperature gets weak. Third, After 40 years of EGS operation, considering variable property fluids results in a 22 °C lower exploitation temperature compared to using constant property fluids, and considering water–rock reactions results in a 15 °C lower exploitation temperature, with a 12.5 % increase in reservoir average porosity. In conclusion, when researching a long-term operating EGS, it is necessary to comprehensively consider the influences of reservoir rock parameters, physical properties of injected fluid, water–rock reaction and other factors. And in the future, attention shall be paid to the two-way coupling of chemical reaction and mechanical deformation of other mineral compositions in the reservoir to the hydro-thermo-chemical field influence, so as to provide more accurate and reliable prediction for the engineering development and utilization of EGS reservoirs.</p></div>","PeriodicalId":37116,"journal":{"name":"Natural Gas Industry B","volume":"10 5","pages":"Pages 533-546"},"PeriodicalIF":3.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71761122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}