scholarly journals Quantitative characterization of collapse and fracture pressure uncertainty based on Monte Carlo simulation

2021 ◽  
Vol 11 (5) ◽  
pp. 2199-2206
Author(s):  
Sheng Ya-nan ◽  
Li Weiting ◽  
Jiang Jinbao ◽  
Lan Kai ◽  
Kong Hua ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Rock Mechanics ◽  
In Situ Stress ◽  
Calculation Model ◽  
Quantitative Characterization ◽  
Fracture Pressure ◽  
Work Area ◽  
Geological Conditions

AbstractThe complex geological conditions of drilling, the difficulty of formation collapse and fracture pressure prediction in South Sichuan work area lead to the complex drilling and frequent failure, which seriously restricts the safe and efficient development of shale gas. In view of this problem, this paper has carried out relevant research. First of all, the existing calculation model of formation collapse and fracture pressure is established and improved; on this basis, the sources of uncertainty in the calculation model of collapse and fracture pressure are analyzed, mainly the in-situ stress and rock mechanics parameters, which have a lot of uncertainties; then, the uncertainty of rock mechanics parameters and in-situ stress is analyzed, and its probability is determined. Finally, based on Monte Carlo simulation, the quantitative characterization method of formation collapse and fracture pressure uncertainty is established. The prediction result of collapse and fracture pressure is no longer a single curve or value, but an interval, which is more practical for drilling in complex geological environment. The results of this study are helpful to better describe the collapse and fracture pressure of complex formation and can provide more valuable reference data for drilling design.

scholarly journals Effect of Advancing Direction of Working Face on Mining Stress Distribution in Deep Coal Mine

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yuesong Tang ◽  
Wenchao Sun ◽  
Xin Zhang ◽  
Pengju Liu
Keyword(s):  
Stress Distribution ◽  
Large Scale ◽  
In Situ Stress ◽  
Deep Mining ◽  
Deep Coal Mine ◽  
Working Face ◽  
Geological Conditions ◽  
Original Rock ◽  
High Level

Deep mining has become the normal state of coal mining; compared with the mine with shallow buried depth, the consequent high level of in situ stress and complex distribution have brought severe threats to the stability of the stope and the surrounding rock of the roadway. In this research, taking the 121304 working face of Kouzidong Mine as the engineering background, the characteristics of mining-induced stress distribution under complex in situ stress environment in deep mining are analyzed by using on-site measurement of the original rock stress and mining stress, establishing a theoretical model centered on the middle section of the working face, and establishing large-scale numerical calculation models for different advancing directions. It was found that under deep mining conditions, the maximum stress of the original rock is 25.12 MPa, and the direction is vertical. The advanced influence range of mining stress is about 150 m, and the abutment pressure presents a three-peak distribution characteristic in front of the working face. The research results provide important theoretical guiding value for guiding the mining of coal mines with similar geological conditions.

scholarly journals Exploring Deep-Rock Mechanics through Mechanical Analysis of Hard-Rock In Situ Coring System

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jianan Li ◽  
Heping Xie ◽  
Ling Chen ◽  
Cong Li ◽  
Zhiqiang He
Keyword(s):  
Rock Mechanics ◽  
Hard Rock ◽  
Design Method ◽  
Drill Pipe ◽  
In Situ Stress ◽  
Drilling Depth ◽  
Innovative Design ◽  
The Core ◽  
Deep Rock

Exploration of deep-rock mechanics has a significant influence on the techniques of mining and rock mechanics. Rock coring technique is the basic method for all rock mechanics study. With the increase of the drilling depth and increasing strength of the hard rock, how to obtain high-quality rock core through various coring techniques is an eternal work. Here an innovative method is applied to design the new coring system to maximize the efficiency of operation. The stress conditions or parameters of rock core in the coring are analyzed, and the mechanism of the core with in situ stress is shown in this paper. The conflict of the core and coring tool chamber is proposed for the innovative design. The innovative design method is fulfilled by the theory of inventive problem solving (TRIZ). An improved coring system for the full-length core with in situ stress was obtained with the solutions of improved coring mechanism, cutting mechanism, and spiral drill pipe.

X‐ray fluorescence spectroscopy and Monte Carlo simulation for quantitative characterization of Bolivian pre‐Hispanic golden artefacts

2020 ◽  
Vol 50 (1) ◽  
pp. 53-67
Author(s):  
Fabio L. Melquiades ◽  
Sandro V. Santos ◽  
Fabio Lopes ◽  
Juan Villanueva ◽  
Jorge L. Ticona ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Fluorescence Spectroscopy ◽  
Quantitative Characterization ◽  
X Ray

scholarly journals Analysis of Surrounding Rock Creep Effect on the Long-Term Stability of Tunnel Secondary Lining

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xiaoqian Zhang ◽  
Chengmin Wei ◽  
Heng Zhang
Keyword(s):  
Stress Measurement ◽  
Soft Rock ◽  
In Situ Stress ◽  
Calculation Model ◽  
Surrounding Rock ◽  
In Situ Stress Measurement ◽  
Rock Creep ◽  
Secondary Lining ◽  
Rock Tunnel

The secondary lining failure of deep buried soft rock tunnel often occurs, which is obviously related to the time factor. The formation mechanism of this phenomenon is studied in this paper. Therefore, the combination of in situ stress measurement and neural network inversion is used to analyze the distribution characteristics of in situ stress. At the same time, the creep characteristics of surrounding rock are tested in laboratory, and the key parameters are obtained. Combined with the characteristics of surrounding rock, the calculation model is established by using discrete element simulation technology and considering the joints of surrounding rock. According to the above multiple information, the stress characteristics of the secondary lining in different time periods are analyzed creatively. Finally, the method of setting arch and adding anchor bolt in key parts is proposed, and significant effect results are obtained.

Surface faceting and compositional evolution of Pd@Au core–shell nanocrystals during in situ annealing

2019 ◽  
Vol 21 (6) ◽  
pp. 3134-3139 ◽  
Author(s):  
Zhemin Wu ◽  
Min Tang ◽  
Xiaoyan Li ◽  
Sai Luo ◽  
Wentao Yuan ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Transformation Process ◽  
Au Nanoparticle ◽  
Core Shell ◽  
Compositional Evolution

A step-wise transformation process of a Pd@Au nanoparticle both structurally and compositionally was observed. Monte Carlo simulation was used to explain the results.

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