Geomechanics for Energy and the Environment最新文献

{"title":"Investigation of fracture-plugging wellbore strengthening: Large scale true tri-axial experiments and field tests","authors":"Dujie Zhang ,&nbsp;Daqi Li ,&nbsp;Junbin Jin ,&nbsp;Jinhua Liu ,&nbsp;Fan Li","doi":"10.1016/j.gete.2024.100573","DOIUrl":"https://doi.org/10.1016/j.gete.2024.100573","url":null,"abstract":"<div><p>Lost circulation caused by developed natural fracture occurs frequently in tight sandstone formations located in Sichuan Basin, China. Fracture-plugging wellbore strengthening by lost circulation materials (FPWSLCM) is a widely applied fluid loss control technique globally. The upper limit of the pressure-bearing capacity treated using FPWSLCM and the relevant engineering influencing factors needs to be investigated further. In this paper, a self-designed large-scale true tri-axial cell was developed to simulate the fracturing and sealing processes in a cubic sandstone sample (30 cm × 30 cm×30 cm) under anisotropic stress to investigate the effect of lost circulation materials (LCM) and the experimental processes on the formation pressure-bearing capacity. Three homogeneous cubic tight sandstone samples taken from Xujiahe Formation in Sichuan Basin with a central hole were used for the wellbore strengthening experiments with FPWSLCM, which was used to eliminate the heterogeneity effect of the rock. SRIPE (SINOPEC Research Institute of Petroleum Engineering) bridge plugging materials were used as LCM. The results show that the formation pressure-bearing capacity after treatment by FPWSLCM was affected by the initial injection pressure, the intrusion amount of LCM, the pressure holding time, and the injection rate. The formation pressure-bearing capacity did not decrease consistently with the increase of plugging zone instability times, but showed an obvious characteristic of fluctuations; the formation pressure-bearing capacity exceeded the fracturing pressure in some cases. The experimental results could be explained by the stress cage theory. Finally, the modified FPWSLCM was applied as a lost circulation control approach by drilling into the tight sandstone formation in the Shunbei oil field, which has a history of severe loss of fluid circulations. The result of the field test indicated that the modified approaches were more successful than the previous approaches used in other wells in this block. The research results are of great significance for improving the success rate of lost circulation control and a reduction in drilling costs.</p></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"39 ","pages":"Article 100573"},"PeriodicalIF":3.3,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141444537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ice-Unfrozen Water on Montmorillonite Surface: a Molecular Dynamics Study","authors":"Pengchang Wei ,&nbsp;Yuan-Yuan Zheng ,&nbsp;Ali Zaoui ,&nbsp;Wei Ma ,&nbsp;Zhifeng Ren","doi":"10.1016/j.gete.2024.100569","DOIUrl":"10.1016/j.gete.2024.100569","url":null,"abstract":"<div><p>The ice-water phase transformation process and its composition distribution in frozen soil at the microscale remains unclear. The molecular dynamic (MD) simulation method was employed to study the phase transformation mechanism of water-ice on montmorillonite (Mt) surface at supercooled temperature (230 ∼ 270 K). The interfacial, structural, and dynamic properties of Mt-ice-water system were discussed. The evolution of unfrozen water content with temperature in MD simulation was compared with previous results from NMR experiments for validation. The simulation results showed that 1) the transformation degree of ice into unfrozen water was almost unchanged in 230 ∼ 260 K, while significantly increased when the temperature rose from 260 to 270 K. 2) The surface effect of montmorillonite played an essential role in the existence of unfrozen water in frozen soil, where coulomb electrostatic interaction was the main influencing factor. 3) Total hydrogen bonds in Mt-water-ice system could be broken due to thermal fluctuations of atoms when the temperature gradually rose. 4) The order of liquidity for the three zones was zone ⅲ (quasi-liquid water) &gt; zone ⅰ (bound water) &gt; zone ⅱ (ice).</p></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"39 ","pages":"Article 100569"},"PeriodicalIF":3.3,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141391169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights of using control theory for minimizing induced seismicity in underground reservoirs","authors":"Diego Gutiérrez-Oribio,&nbsp;Ioannis Stefanou","doi":"10.1016/j.gete.2024.100570","DOIUrl":"https://doi.org/10.1016/j.gete.2024.100570","url":null,"abstract":"<div><p>Deep Geothermal Energy, Carbon Capture, and Storage and Hydrogen Storage have significant potential to meet the large-scale needs of the energy sector and reduce the CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> emissions. However, the injection of fluids into the earth’s crust, upon which these activities rely, can lead to the formation of new seismogenic faults or the reactivation of existing ones, thereby causing earthquakes. In this study, we propose a novel approach based on control theory to address this issue. First, we obtain a simplified model of induced seismicity due to fluid injections in an underground reservoir using a diffusion equation in three dimensions. Then, we design a robust tracking control approach to force the seismicity rate to follow desired references. In this way, the induced seismicity is minimized while ensuring fluid circulation for the needs of renewable energy production and storage. The designed control guarantees the achievement of the control objectives even in the presence of system uncertainties and unknown dynamics. Finally, we present simulations of a simplified geothermal reservoir under different scenarios of energy demand to show the reliability and performance of the control approach, opening new perspectives for field experiments based on real-time regulators.</p></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"39 ","pages":"Article 100570"},"PeriodicalIF":3.3,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352380824000376/pdfft?md5=724561e8c0e2c4cdb51d5b7ae2ef2eaf&pid=1-s2.0-S2352380824000376-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141433822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Investigation and analysis of the macro- and micro-responses of bentonite-sand mixtures to temperature","authors":"An Li ,&nbsp;Wei-Qiang Feng ,&nbsp;Ze-Jian Chen ,&nbsp;Numan Mailk ,&nbsp;Jian-Hua Yin ,&nbsp;Chao Zhou","doi":"10.1016/j.gete.2024.100565","DOIUrl":"10.1016/j.gete.2024.100565","url":null,"abstract":"<div><p>Bentonite-sand mixture has been proposed as a buffer material of high-level radioactive waste (HLW) repositories in many countries. The elevated temperature in HLW repositories significantly influences the properties and behaviour of the surrounding buffers. However, to date the mechanism of temperature effects on the behaviour of the bentonite buffer is not well understood. This study is aimed at clarifying the macro- and micro-responses of bentonite-sand mixtures by conducting cone penetration test, rheometer test, flask volumetric test, scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) at different temperatures. The results from macro-experiments show that the liquid limit and yield stress increased while bound water content decreased with increasing temperature. The normalized relationships disclose the sand content dramatically affects the degree of temperature influence on the macro-behaviour. SEM and MIP results present that the contact manner between particles converted from edge-to-face to the edge-to-edge association and some intra-aggregate pores merged to form inter-aggregate pores as temperature increases. The mechanisms of the increasing temperature influence on the responses of bentonite-sand mixtures can be inferred that: 1) the diffuse double layer is supposed to decrease since more ions were electrolyzed from montmorillonite particles, thereby, increasing the ion concentration and changing the ion valence; 2) the slight shrinkage of diffuse double layer produced nano-fissures, causing water-hold capacity to increase; 3) the temperature-induced transition from bound water into free water results in an increase of liquid volume; 4) increasing temperature led to increased inter-particle repulsive force. Furthermore, an empirical model was proposed to predict the yield stress of bentonite dispersion incorporating the combined effects of sand content and temperature.</p></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"38 ","pages":"Article 100565"},"PeriodicalIF":5.1,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141136368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A thermoplastic clay constitutive model with temperature dependent evolution of stress anisotropy","authors":"Irfan Ahmad Shah ,&nbsp;Abhishek Ghosh Dastider ,&nbsp;Prasenjit Basu ,&nbsp;Santiram Chatterjee","doi":"10.1016/j.gete.2024.100568","DOIUrl":"10.1016/j.gete.2024.100568","url":null,"abstract":"<div><p>This paper presents a thermomechanical constitutive model that captures temperature dependent evolutions of preconsolidation stress and stress anisotropy in normally consolidated and lightly overconsolidated saturated clays. Following a non-associative flow rule, the model was formulated to account for the rate of evolution of stress anisotropy as a function of temperature. A temperature-dependent rotational hardening parameter was introduced and calibrated employing a simple optimization algorithm for four different clays. The developed model was further implemented in a finite element (FE) analysis software for use in boundary value problems. Success of such numerical implementation and predictive performance of the constitutive model was further verified through FE simulations of drained and undrained triaxial tests on saturated clays at reference and elevated temperature. FEA results obtained from these simulations agreed very well with test data reported in the literature.</p></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"38 ","pages":"Article 100568"},"PeriodicalIF":5.1,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141139387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cyclic swell shrink behaviour of lime and lignosulphonate amended expansive soil—An experimental quantification and comparison","authors":"G. Landlin ,&nbsp;S. Bhuvaneshwari","doi":"10.1016/j.gete.2023.100440","DOIUrl":"10.1016/j.gete.2023.100440","url":null,"abstract":"<div><p>The behaviour of expansive soils is majorly influenced by the mineralogy and the environmental conditions contributed by the seasonal moisture changes. Many structures found on the expansive soil depict severe distress due to the volume change behaviour of the soil. The volume changes correspond to moisture fluctuations which occur with the wetting–drying cycles associated with climatic variations. The wetting–drying​ cycles also impact the chemical treatment methods adopted to curtail swelling and shrinkage. The present study evaluates and compares the magnitude of swelling and shrinkage depicted by Lime and Lignosulphonate amended soils under wetting and drying cycles imposed under laboratory conditions. A specially modified oedometer apparatus was adopted to simulate the field drying conditions. The untreated soil exhibits higher swelling strain than the shrinkage strains with cycles of wetting and drying. There is a decrease of nearly 9% in swelling and 5% in shrinkage from the first cycle to steady state cycle. The swelling strain followed a decline to the steady state, however lime and LS amended soil depicted an initial decrease and then an increase in swelling strains before steady state. The treated and untreated soils also attain equilibrium characterized by different bandwidths and also exhibit difference in swelling and shrinkage rates, with untreated soil exhibiting a longer time to complete the swell-shrink cycles. The study further quantifies these variations for treated and untreated soil and the respective rates of primary and secondary swelling and shrinkage. The results are also justified with a physicochemical analysis of the leachate collected during the wetting–drying cycles.</p></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"38 ","pages":"Article 100440"},"PeriodicalIF":5.1,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44669640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A three-dimensional elastoplastic constitutive model incorporating Lode angle dependence","authors":"Jiacun Liu ,&nbsp;Xing Li ,&nbsp;Chonglang Wang ,&nbsp;Ying Xu ,&nbsp;Kaiwen Xia","doi":"10.1016/j.gete.2024.100567","DOIUrl":"https://doi.org/10.1016/j.gete.2024.100567","url":null,"abstract":"<div><p>A comprehensive three-dimensional elastoplastic constitutive model is presented to characterize the stress-strain behavior of cement stone under the true triaxial stress state. This constitutive model incorporates a three-dimensional yield function and a three-dimensional potential function. The three-dimensional yield function is designed to accurately represent the true triaxial stress state during hardening. The three-dimensional potential function is devised to depict the plastic flow direction under true triaxial stress state. The yield and potential functions include parameters that control the shape of the deviatoric and meridian planes, and these parameters vary with the plastic internal variable. Consequently, the yield function can accurately describe the stress state, and the potential function can precisely capture the variations in plastic flow direction. Additionally, a detailed procedure for determining the parameters of the yield function and potential function is proposed based on the full deformation process. The constitutive model is presented in the form of analytical solution. The comparison of experimental data with the constitutive model confirms its accuracy and validity. A sensitivity analysis of the deviatoric and meridian parameters in the potential function is performed, shedding light on their impact on the model behavior. Furthermore, the significance of incorporating Lode angle dependence into the potential function is discussed, emphasizing its essential role in accurately capturing strain in the direction of the intermediate principal stress.</p></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"38 ","pages":"Article 100567"},"PeriodicalIF":5.1,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141244612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-mode flow simulation of fracture-cavity reservoirs and predicting oil accumulation based on hydro-mechanical-damage coupling model","authors":"Hongshan Wang ,&nbsp;Rujun Wang ,&nbsp;Yintao Zhang ,&nbsp;Jing Li ,&nbsp;Zhiping Wu ,&nbsp;Chong Sun ,&nbsp;Yishuai Liu","doi":"10.1016/j.gete.2024.100566","DOIUrl":"https://doi.org/10.1016/j.gete.2024.100566","url":null,"abstract":"<div><p>Fracture-cavity carbonate reservoirs exhibit significant heterogeneity with diverse flow modes, including porous media seepage and free flow, within fractures and cavities. This complexity is further compounded by tectonic stress. Traditional oil reservoir seepage theories often struggle to depict these fluid flow characteristics accurately. This study employs a hydraulic-mechanical-damage coupling model to conduct numerical simulations of multi-mode fluid flow within fracture-cavity reservoirs. This approach elucidates fluid flow mechanisms influenced by multi-field coupling and predicts areas favorable for oil accumulation based on actual geological models. The results show that (1) while the secondary fractures developed in the penetrating-type fracture-cavity body result in the highest oil migration efficiency and initial production, the production from this body type decreases rapidly in the later stage. Secondary fractures in the sandwich-type and side-type cavity bodies primarily offer storage, resulting in lower initial production but a slower production decline. (2) In the S1 stress state, secondary fractures primarily connect fracture-cavity bodies, whereas, in the S2 stress state, they mainly contribute to oil accumulation. (3) Secondary fractures function as efficient conduits for oil migration, and their distribution is influenced by the presence of fault zones and cavities. Consequently, the intersection of cavities and fault zones with secondary fractures leads to the formation of favorable oil accumulation areas.</p></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"38 ","pages":"Article 100566"},"PeriodicalIF":5.1,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141083784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compaction localization in geomaterials: A mechanically consistent failure criterion","authors":"Roberto J. Cier ,&nbsp;Nicolas A. Labanda ,&nbsp;Victor M. Calo","doi":"10.1016/j.gete.2024.100564","DOIUrl":"10.1016/j.gete.2024.100564","url":null,"abstract":"<div><p>Compaction bands play a key role in the deformation processes of porous rocks and explain different aspects of physical processes in geological formations. The state-of-the-art description of the localized strains that lead to compaction banding has limitations from the mechanical point of view. Thus, we describe the phenomenon using a consistent axiomatic formulation. We build a viscoplastic model using minimal assumptions; we base our model on six principles to study compaction band strain localization triggered by viscous effects. We analyze different stress states to determine the conditions that trigger compaction bands. Laboratory experiments show that a material undergoes different strain localizations depending on the confinement pressure; thus, we perform a series of numerical experiments that reproduce these phenomena under varying triaxial compression conditions. These simulations use a simple viscoplastic constitutive model for creep based on Perzyna’s viscoplasticity and show how confinement changes the strain localization type for different triaxial tests.</p></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"39 ","pages":"Article 100564"},"PeriodicalIF":3.3,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352380824000315/pdfft?md5=003cd80e9c3eff35d70d29dec050b100&pid=1-s2.0-S2352380824000315-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141029311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"A preliminary investigation on the mechanical behaviour of a stiff Italian clay in the context of hydrogen storage","authors":"Andrea Ciancimino ,&nbsp;Renato Maria Cosentini ,&nbsp;Sebastiano Foti ,&nbsp;Alessandro Messori ,&nbsp;Hidayat Ullah ,&nbsp;Giorgio Volonté ,&nbsp;Guido Musso","doi":"10.1016/j.gete.2024.100562","DOIUrl":"https://doi.org/10.1016/j.gete.2024.100562","url":null,"abstract":"<div><p>The large-scale use of renewable energy sources is closely linked to the ability to store excess energy generated during periods of overproduction for use when demand is at a peak. Storing green energy is therefore a key component in the move towards a carbon-neutral economy. Underground hydrogen storage in depleted oil and gas reservoirs may provide an efficient long-term solution. Cyclic injection and production of hydrogen alter the chemo-hydro-mechanical conditions of the reservoir and caprocks, and possible geomechanical consequences of such alterations must be preliminarily assessed for safe storage operations. This study aims at exploring the possible effects of cyclic mechanical loads, such as those that might be induced by hydrogen storage and production, on the mechanical behaviour of a clayey caprock. A series of triaxial tests, both monotonic and cyclic, were carried out on undisturbed samples of a stiff Italian clay cored from a caprock formation overlying a hydrocarbon reservoir. The results show that the material response is characterized by the distinctive stress-strain behaviour of stiff clays, with a rather high fragility, which was found to be highly dependent on the loading strain rate. During laboratory experiments conducted at frequencies larger than in situ ones, cyclic loading under stress control causes a gradual degradation of the material structure leading to the formation of a clear shear band followed by a reduction in shear strength. Eventually, failure occurs as the peak shear strength approaches the applied load. The progressive destructuration also implies a reduction in P- and S-wave propagation velocities and a significant change in the signal shape, which is therefore a promising parameter for monitoring the material degradation process.</p></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"38 ","pages":"Article 100562"},"PeriodicalIF":5.1,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352380824000297/pdfft?md5=5b4c4db3285232ca4f1afb1f64f06867&pid=1-s2.0-S2352380824000297-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140918463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}