Proceedings 56th US Rock Mechanics / Geomechanics Symposium最新文献_第2页

Effect of Disturbance Factor Distribution Function on Stability of an Open Pit Mine 扰动因子分布函数对露天矿稳定性的影响

Proceedings 56th US Rock Mechanics / Geomechanics Symposium Pub Date : 2022-06-26 DOI: 10.56952/arma-2022-0133

Sina Javankhoshdel, T. Ma, B. Cami, T. Yacoub, B. Corkum, J. Curran

{"title":"Effect of Disturbance Factor Distribution Function on Stability of an Open Pit Mine","authors":"Sina Javankhoshdel, T. Ma, B. Cami, T. Yacoub, B. Corkum, J. Curran","doi":"10.56952/arma-2022-0133","DOIUrl":"https://doi.org/10.56952/arma-2022-0133","url":null,"abstract":"The disturbance factor (D) is a parameter in the Generalized Hoek-Brown failure criterion for rock slopes in slope stability. It represents the subsurface damage to the rock material properties resulting from blasting and stress relaxation during excavations. Within the region of assumed damage, a number between zero (undisturbed) and unity (very disturbed) is prescribed as the value of the disturbance factor. Most commonly a uniform value of D is assumed within the entire region of damage, but little research has been done to study the impact of the variation in the D parameter on stability. Through use of an example, this paper examines the effect of various distribution functions of D through the damaged region, such namely, as constant, linearly varying, and exponentially varying. The failure modes and factors of safety for the slope as determined via limit equilibrium are also compared with finite element analyses. Varying the distribution of the damage function was found to significantly affect the failure mode and factor of safety. It is recommended that practitioners adopt care to select an appropriate distribution for slope stability analysis.","PeriodicalId":418045,"journal":{"name":"Proceedings 56th US Rock Mechanics / Geomechanics Symposium","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128954727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of interlaminar difference on Height propagation behavior of hydraulic fracture in Lucaogou Shale 层间差异对芦草沟页岩水力裂缝高度扩展行为的影响

Proceedings 56th US Rock Mechanics / Geomechanics Symposium Pub Date : 2022-06-26 DOI: 10.56952/arma-2022-0193

Xiaohuan Zhang, Shicheng Zhang, Y. Zou, Jianmin Li, Jun-chao Wang, Danyang Zhu, G. Zhou, Can Yang

{"title":"Effect of interlaminar difference on Height propagation behavior of hydraulic fracture in Lucaogou Shale","authors":"Xiaohuan Zhang, Shicheng Zhang, Y. Zou, Jianmin Li, Jun-chao Wang, Danyang Zhu, G. Zhou, Can Yang","doi":"10.56952/arma-2022-0193","DOIUrl":"https://doi.org/10.56952/arma-2022-0193","url":null,"abstract":"The shale oil reservoir of Lucaogou Formation is characterized by complex lithology changes in vertical direction and lamination. To simulate the lithology variation of shale oil formation, downhole cores with different lithologies were prepared and bonded to layered samples. After that, the influence of interlaminar difference on propagation behavior of hydraulic fractures (HFs) was investigated through laboratory hydraulic fracturing and mechanical characteristics analysis. The result shows that mechanically weak bedding planes (BPs) leads to obvious anisotropy of rock mechanical properties. The rock samples is unstable when loaded along the parallel BPs direction, the tensile strength decline significantly, which is about 20% of the tensile strength measured perpendicular to BPs. The brittleness of rock samples measured parallel to BPs is greater than that measured perpendicular to BPs, by about two times. This results in HFs induced by low-viscosity slickwater are easily arrested by BPs, can not penetrate interlayer. HFs induced by high viscosity gel can penetrate the bonding interface. The difference of tensile strength between layers increases, the decrease degree of fracture width increases 2.5 times. This will impede proppant placement in interlayer. This research results provide a basis for the optimization of hydraulic fracturing of Lucaogou shale oil reservoir.","PeriodicalId":418045,"journal":{"name":"Proceedings 56th US Rock Mechanics / Geomechanics Symposium","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115097674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Influencing Factors of Acid Etching Fracture Conductivity of Tuff Reservoir in Northeastern Sichuan Block 川东北地块凝灰岩储层酸蚀裂缝导电性影响因素

Proceedings 56th US Rock Mechanics / Geomechanics Symposium Pub Date : 2022-06-26 DOI: 10.56952/arma-2022-0155

Jinyang Xie, Luo Zuo, B. Hou, Yifan Dai, Jiaxin Li, L. Zhuang, D. Elsworth

{"title":"Influencing Factors of Acid Etching Fracture Conductivity of Tuff Reservoir in Northeastern Sichuan Block","authors":"Jinyang Xie, Luo Zuo, B. Hou, Yifan Dai, Jiaxin Li, L. Zhuang, D. Elsworth","doi":"10.56952/arma-2022-0155","DOIUrl":"https://doi.org/10.56952/arma-2022-0155","url":null,"abstract":"With the continuous depth breakthrough of two ultra-deep exploration wells in northeastern Sichuan block, tuff reservoir was finally discovered at the depth of 6700-7300 m. It belongs to ultra-deep tight gas reservoir with low brittle mineral content and high clay content. Hydraulic fracturing is hard to be reformed this special reservoir, easy to appear hydration expansion and other problems. However, the research and development of such tight tuff reservoir with high temperature and high pressure are relatively low in the domestic and overseas until now. Therefore, it is of great significance to carry out experimental research on relevant reservoir reconstruction methods of such rocks and explore the factors of fracture conductivity here. In this study, the influence of acid type, sanding concentrations, proppant size was research by a new experimental installation. The factors of fracture conductivity are analyzed by experimental data and the reconstitution of fracture surface. The results show that before the abnormal point, the acid etching effect of crosslinked acid on tuff is better than that of gelling acid. At the condition of closure pressure is lower 30 MPa, the higher sanding concentrations, the higher fracture conductivity, then narrowed the gap among them. Meanwhile, the larger proppant size, the higher fracture conductivity in low closure pressure. With increasing closure pressure, fracture conductivity of smaller size proppant decreased slowly. In conclusion, it is also convenient for the field operation to choose the best acid and proppant parameters.","PeriodicalId":418045,"journal":{"name":"Proceedings 56th US Rock Mechanics / Geomechanics Symposium","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126687478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical simulation of triaxial experimental results on Sandstone using critical state mechanics 砂岩三轴试验结果的临界状态力学数值模拟

Proceedings 56th US Rock Mechanics / Geomechanics Symposium Pub Date : 2022-06-26 DOI: 10.56952/arma-2022-0383

N. Reppas, C. Davie, B. Wetenhall, Y. Gui, Jianjun Ma

引用次数: 1

Development and Evaluation of a Novel Delayed Crosslink, Low Friction, High Density Brine-Based Fracturing Fluid for Ultra-Deep Fracturing Stimulation 新型延迟交联、低摩擦、高密度盐基超深层压裂压裂液的开发与评价

Proceedings 56th US Rock Mechanics / Geomechanics Symposium Pub Date : 2022-06-26 DOI: 10.56952/arma-2022-0085

Hang Xu, Fu-jian Zhou, Hao Wu, Yuan Li, L. Shen, Erdong Yao

{"title":"Development and Evaluation of a Novel Delayed Crosslink, Low Friction, High Density Brine-Based Fracturing Fluid for Ultra-Deep Fracturing Stimulation","authors":"Hang Xu, Fu-jian Zhou, Hao Wu, Yuan Li, L. Shen, Erdong Yao","doi":"10.56952/arma-2022-0085","DOIUrl":"https://doi.org/10.56952/arma-2022-0085","url":null,"abstract":"Using heavyweight brines as a base for fracturing fluids is an effective method for solving the problem of exorbitant surface pressure during deep well fracturing process. However, higher fluid densities can lead to higher friction pressures, and with the well depth increases, the travel time to the mudline prolongs, resulting in the demand for extended crosslink delay times. Therefore, fracturing fluids that provide flexibility in density, lower friction and extended crosslink times are required for effective stimulation in ultra-deep reservoirs. This paper presents details of laboratory studies to develop and evaluate a novel weighted fracturing fluid. The main additives of the novel system were sequentially synthesized, including modified guar gum, a new weighting agent and an organic boron-zirconium crosslinker. Afterwards, a series of lab experiments were carried out to test the comprehensive performances of the novel system, such as temperature and shear resistance, friction reduction, gel breaking performance and core damage rate. The optimal formula of fracturing fluid was 54.3 wt.% weighting agent + 0.4 wt.% modified guar gum + 1.0 wt.% pH regulator + 0.5 wt.% crosslinker. Results show that the novel weighted fracturing fluid is a good choice for ultra-deep reservoirs hydraulic stimulation and hence improving the recovery.","PeriodicalId":418045,"journal":{"name":"Proceedings 56th US Rock Mechanics / Geomechanics Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121808357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Numerical Investigation of the 2020 M4.2 Stanton, Texas Seismicity Sequence Using 3D Poroelastic Modeling 基于三维孔隙弹性模型的2020年德州斯坦顿M4.2地震活动性序列数值研究

Proceedings 56th US Rock Mechanics / Geomechanics Symposium Pub Date : 2022-06-26 DOI: 10.56952/arma-2022-0285

Lei Jin, R. Lippoldt, W. Curry, S. Hussenoeder, Peeyush Bhargava

{"title":"A Numerical Investigation of the 2020 M4.2 Stanton, Texas Seismicity Sequence Using 3D Poroelastic Modeling","authors":"Lei Jin, R. Lippoldt, W. Curry, S. Hussenoeder, Peeyush Bhargava","doi":"10.56952/arma-2022-0285","DOIUrl":"https://doi.org/10.56952/arma-2022-0285","url":null,"abstract":"This paper investigates a seismicity sequence that occurred near Stanton, TX between December 2020 and February 2021 with event magnitudes peaking at 4.2. The historically aseismic area has been undergoing shallow salt water disposal (SWD) since the early 1980s, and deep SWD in the last decade. We perform a 3D fully coupled hydro-geomechanical investigation into potential links between the M4.2 event sequence and the surrounding decades-long, multi-zone SWD activities involving 183 SWD wells in a 900 mile2 area. We include faults interpreted from reflection seismic data into the model and survey six fault scenarios with various fault-zone structures and fault upper extents. We compare the modeled Coulomb stress changes against earthquake triggering thresholds obtained from a detailed in-situ stress model, and identify implausible and plausible scenarios. The plausible scenarios yield an excellent match between the critical Coulomb failure function (CFF) propagation and the onset of seismicity in both space and time, and are further supported by their revealing of possible earlier events that were later detected through template matching. Together, these findings strongly suggest a SWD origin of the M4.2 seismicity sequence. The modeling also suggests that near-hypocenter Coulomb stresses are sourced primarily from several deep disposal wells and secondarily from the remaining deep wells and shallower wells given the likely fault configurations. We also analyze roles of fault-zone structures, non-seismogenic faults, and mechanically time-dependent formations. Our work illustrates the importance of physics-based modeling that accounts for faults, formations, wells, and poroelasticity in understanding causes of seismicity.","PeriodicalId":418045,"journal":{"name":"Proceedings 56th US Rock Mechanics / Geomechanics Symposium","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131206997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Evolution of bentonite under high temperature heating and hydration: bench-scale laboratory experiments and coupled thermo-hydro-mechanical modeling 高温加热和水化作用下膨润土的演化:实验室实验和热-水-力耦合模型

Proceedings 56th US Rock Mechanics / Geomechanics Symposium Pub Date : 2022-06-26 DOI: 10.56952/arma-2022-0730

Sangcheol Yoon, S. Borglin, Chun Chang, C. Chou, Liange Zheng, Yuxin Wu

{"title":"Evolution of bentonite under high temperature heating and hydration: bench-scale laboratory experiments and coupled thermo-hydro-mechanical modeling","authors":"Sangcheol Yoon, S. Borglin, Chun Chang, C. Chou, Liange Zheng, Yuxin Wu","doi":"10.56952/arma-2022-0730","DOIUrl":"https://doi.org/10.56952/arma-2022-0730","url":null,"abstract":"Bentonite buffer in the geological repository for high-level radioactive waste undergoes the heating from the waste package and hydration from the geological formation and goes through coupled thermo-hydro-mechanical-chemical (THMC) changes over the life span of a repository. For a better understanding of such process under higher temperatures, we report bench-scale laboratory experiments with heating up to 200◦C and the corresponding THM model. The bench-scale laboratory experiments included two test columns, with the non-heated control column undergoing only hydration, and a heated column experiencing both heating in the center up to 200◦C and hydration from a sand-clay boundary surrounding the column. During the experiment, we took frequent X-ray CT images to provide insight into the spatio-temporal evolution of THMC due to heating, hydration, bentonite swelling/compression. Based on the experiment setup, 2-D axisymmetric simulations were performed for the heated column and the mechanical changes were investigated in 3-D. The model first matched the temperature evolution with step-wise temperature boundary conditions at the heater and calibrated the thermal conductivity and specific heat of the materials. Then model interpreted the spatio-temporal distribution of bulk density by considering the combined effect of hydration, fluid pressure, and porosity change due to swelling/compression.","PeriodicalId":418045,"journal":{"name":"Proceedings 56th US Rock Mechanics / Geomechanics Symposium","volume":"26 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132914617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelling stress evolution in cement plugs during hydration 模拟水泥塞水化过程中的应力演化

Proceedings 56th US Rock Mechanics / Geomechanics Symposium Pub Date : 2022-06-26 DOI: 10.56952/arma-2022-0096

A. Moghadam, A. Corina

{"title":"Modelling stress evolution in cement plugs during hydration","authors":"A. Moghadam, A. Corina","doi":"10.56952/arma-2022-0096","DOIUrl":"https://doi.org/10.56952/arma-2022-0096","url":null,"abstract":"In this work, we have developed a methodology to model the stress evolution in cement plugs during hydration. The model begins with the slurry state of cement and calculates the water consumption and void creation over time as the hydration reactions progress. The void volume change due to chemical shrinkage is imported into a coupled mechanical model that calculates the pore pressure drop and the resulting change in stresses. The results of the proposed modelling methodology are verified using lab experiments from the literature. The results provide new insights in understanding cement behavior under lab and field conditions. Under most scenarios, cement’s pore pressure drops to saturation pressure of water which leads to partial evaporation of the remaining pore water. This pore pressure drop controls the radial stress change, according to the theory of poroelasticity. For a plug set under an initial pressure of 5 MPa, the radial stress drops to 1.6 MPa after 20 hours of curing. This stress drop can cause the cement to debond from the casing, if the fluid pressure above the plug exceeds the final radial stress. This methodology can be extended to annular cements and initial cement stress after placement can be readily calculated.","PeriodicalId":418045,"journal":{"name":"Proceedings 56th US Rock Mechanics / Geomechanics Symposium","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134574769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Insights into the anisotropic, hydro-mechanical behavior of Opalinus Clay through experimental and microstructural investigations 通过实验和微观结构研究了解蛋白石粘土的各向异性、水力学行为

Proceedings 56th US Rock Mechanics / Geomechanics Symposium Pub Date : 2022-06-26 DOI: 10.56952/arma-2022-0353

Lisa Winhausen, Kavan Khaledi, M. Jalali, F. Amann

{"title":"Insights into the anisotropic, hydro-mechanical behavior of Opalinus Clay through experimental and microstructural investigations","authors":"Lisa Winhausen, Kavan Khaledi, M. Jalali, F. Amann","doi":"10.56952/arma-2022-0353","DOIUrl":"https://doi.org/10.56952/arma-2022-0353","url":null,"abstract":"For analyzing the influence of structural anisotropy on the hydro-mechanical behavior of a clay shale, we performed three consolidated, undrained triaxial compression tests with different geometric specimen configurations. Opalinus Clay specimens were tested with bedding plane orientations of 30°, 60°, and 90° with respect to the horizontal. Results indicated different peak strengths at failure with highest and lowest values for the 90° and 30°-specimens, respectively. Failure occurred at different mean effective stresses with different magnitudes of pore water pressure built up. The 30°-specimen showed a decreasing effective mean stress up to and beyond failure compared to the initial effective consolidation stress of 10 MPa, while the 90°-specimen increased in effective mean stress during undrained loading. Dilation was found to be highest in the 30°-specimen and lowest in the 60°-specimen, demonstrated by both the effective stress path and the post-experimental microstructural analysis of the shear zones. The macroscopic shear band formed parallel to the bedding plane orientation for the specimen loaded in 60°-orientation. Here, only minor microstructural fabric changes such as increased porosity or deformed grain structures were observed, which verifies the minor volume changes inferred from the effective stress path.","PeriodicalId":418045,"journal":{"name":"Proceedings 56th US Rock Mechanics / Geomechanics Symposium","volume":"413 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121705652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An Open-access Well Integrity Tool to Study Legacy Wells Re-Purposed for CO2 Injection 一种开放式井完整性工具，用于研究重新注入二氧化碳的遗留井

Proceedings 56th US Rock Mechanics / Geomechanics Symposium Pub Date : 2022-06-26 DOI: 10.56952/arma-2022-0225

C. Joulin

{"title":"An Open-access Well Integrity Tool to Study Legacy Wells Re-Purposed for CO2 Injection","authors":"C. Joulin","doi":"10.56952/arma-2022-0225","DOIUrl":"https://doi.org/10.56952/arma-2022-0225","url":null,"abstract":"This work presents a well integrity tool based on an analytical model describing the thermo-poroelastic behaviour of wells in the so-called drained conditions and plane-strain conditions. The analytical model takes into account the pore pressure, uniform temperatures changes across the well and the cement's initial state of stress. The well integrity tool estimates the potential for debonding, tensile and shear fracturing of the rock and the cement sheath using computed stress profiles and the Mohr-Coulomb failure criterion. The tool is suited to study vertical well sections consisting of a single casing and cement sheath inside a porous or non-porous rock formation. The tool is built within a Microsoft Excel spreadsheet to make it as accessible, portable and flexible as possible. Furthermore, this work also presents an integrity analysis of a characteristic gas production well re-purposed for CO2 injection. This investigation covers the construction of the well, reservoir depletion, CO2 injection and long-term storage conditions. This demonstrates the type of data necessary for the tool to function, the different results and outputs that may be expected and the type of conclusions that may be drawn from them. This work is part of wider efforts by TotalEnergies to drive the development of safe CO2 storage technology and in particular to progress the understanding of well integrity loss mechanisms.","PeriodicalId":418045,"journal":{"name":"Proceedings 56th US Rock Mechanics / Geomechanics Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126057367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1