Tightness Analysis of Underground Natural Gas and Oil Storage Caverns With Limit Pillar Widths in Bedded Rock Salt

Zhang, Nan; Shi, Xilin; Zhang, Yun; Shan, Pengfei

doi:10.1109/access.2020.2966006

Cited by 45 publications

(16 citation statements)

References 46 publications

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“…When the stress concentration area reaches the release limit under the influence of mining, the stress release will occur. Therefore, the rock mass in the stress release area will deflect to the free side of the floor without reinforced support under the influence of the released high stress, resulting in floor heave [21][22][23][24]. When the limit equilibrium state is reached, the active pressure P1 and passive pressure P2 under floor rock mass can be expressed as [25][26][27][28] With the continuous advance of the working face, the side of the roadway will produce the effect of load transfer to the floor.…”

Section: Theoretical Calculation Of Support Parameter Optimizationmentioning

confidence: 99%

Research on Mechanism and Control of Floor Heave of Mining-Influenced Roadway in Top Coal Caving Working Face

Lai

Shan

et al. 2020

Energies

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The stability of the surrounding rock is the key problem regarding the normal use of coal mine roadways, and the floor heave of roadways is one of the key factors that can restrict high-yield and high-efficiency mining. Based on the 1305 auxiliary transportation roadway geological conditions in the Dananhu No. 1 Coal Mine, Xinjiang, the mechanism of roadway floor heave was studied by field geological investigation, theoretical analysis, and numerical simulation. We think that the surrounding rock of the roadway presents asymmetrical shrinkage under the original support condition, and it is the extrusion flow type floor heave. The bottom without support and influence of mining are the important causes of floor heave. Therefore, the optimal support scheme is proposed and verified. The results show that the maximum damage depth of the roadway floor is 3.2 m, and the damage depth of the floor of roadway ribs is 3.05 m. The floor heave was decreased from 735 mm to 268 mm, and the force of the rib bolts was reduced from 309 kN to 90 kN after using the optimization supporting scheme. This scheme effectively alleviated the "squeeze" effect of the two ribs on the soft rock floor, and the surrounding rock system achieves long-term stability after optimized support. This provides scientific guidance for field safe mining.Energies 2020, 13, 381 2 of 14 the surrounding rock and the complexity of occurrence in the environment, the distribution law of floor heave deformation is very complex. In view of the mechanism of unsymmetrical floor heave of a mining roadway in a fully mechanized top coal caving face, we put forward corresponding countermeasures to ensure the normal operation and safety of the roadway.In recent years, many experts and scholars have carried out a series of research studies on the mechanism and control of roadway floor heave under different conditions. Sun et al. [9], based on Euler's formula, analyzed the deformation and failure mechanism of different layered rock roadways by the theory of pressure bar stability, Mohr-Coulomb strength criterion, and the deflection failure mechanical model. According to the flexibility of rock mass, he established new mechanical strength parameters to obtain the best support method by studying the change rule of strength parameters and making full use of the stability of the surrounding rock. Sungsoon Mo et al. [10] introduce some of the main floor heave events in the development of the Glencore Bulga Underground plant. Their study indicates that the high horizontal stress of the roadways surrounding rocks and certain types of floor lithology configuration are the reasons for the failures of floor strata. Zhai et al. [11] analyzed that the bottom depressurized trough can effectively control the floor heave, which is beneficial to the long-term stability of the roadway. The surrounding rock of the large deformation chamber is in a stable state after the excavation of the bottom floor decompression trough and the joint support of the bolt and jet. Gong et al. [12] establishe...

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Section: Theoretical Calculation Of Support Parameter Optimizationmentioning

confidence: 99%

Research on Mechanism and Control of Floor Heave of Mining-Influenced Roadway in Top Coal Caving Working Face

Lai

Shan

et al. 2020

Energies

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“…Energy is closely related to economy, environment, and social development [3][4][5]. Especially with the fast development of the economy and the resulting rapid growth of energy consumption [6][7][8][9][10][11][12][13], the need for energy is increasingly growing, especially for fossil energy such as crude oil, leading to the increasing dependence on foreign oil every year [14]. In 2018, China's oil demand exceeded 600 million tons for the first time, and its dependence on foreign countries was close to 70%.…”

Section: Introductionmentioning

confidence: 99%

Microscopic Pore Structure of Surrounding Rock for Underground Strategic Petroleum Reserve (SPR) Caverns in Bedded Rock Salt

et al. 2020

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Using salt caverns for an underground strategic petroleum reserve (SPR) is considered as an ideal approach due to the excellent characteristics of low porosity, low permeability, self-healing of damage, and strong plastic deformation ability of rock salt. Salt deposits in China are mostly layered rock salt structures, with the characteristics of many interlayers, bringing great challenges for the construction of SPR facilities. Studying the microscopic pore characteristics of the rock surrounding SPR salt caverns in different environments (with brine and crude oil erosion) is necessary because the essence of mechanical and permeability characteristics is the macroscopic embodiment of the microscopic pore structure. In this paper, XRD tests and SEM tests are carried out to determine the physical properties of storage media and surrounding rock. Gas adsorption tests and mercury intrusion tests are carried out to analyze the microscopic pore structure, specific surface area variation and total aperture distribution characteristics of SPR salt cavern host rock. Results show that: (1) Large numbers of cores in interlayer and caprock may provide favorable channels for the leakage of high-pressure crude oil and brine. (2) The blockage of pores by macromolecular organic matter (colloid and asphaltene) in crude oil will not significantly change the structural characteristics of the rock skeleton, which is beneficial to the long-term operation of the SPR salt cavern. (3) The water–rock interaction will bring obvious changes in the micro-pore structure of rock and increase the leakage risk of the storage medium. The results can provide theoretical bases and methods for the tightness analysis of China’s first underground SPR salt cavern.

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“…However, different from the salt domes abroad, most of the salt rocks in China have a bedded structure. The bedded salt rocks contain numerous non-salt interlayers, consist of thin salt layers and have a low grade of halite [34]- [37]. These conditions greatly increase the difficulty and cost of cavern construction in bedded salt rocks.…”

Section: Introductionmentioning

confidence: 99%

Research on the Stability and Treatments of Natural Gas Storage Caverns With Different Shapes in Bedded Salt Rocks

et al. 2020

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Because of complex geo-conditions, many caverns by solution mining in bedded salt rocks have different irregular shapes. To verify the feasibility of using irregular-shaped caverns for underground gas storage (UGS), four typical cavern-shapes are selected, and the stability of each type is evaluated and compared by using the numerical simulation methods. The simulation results show that the UGS salt cavern with irregular wall shape has the lowest volume shrinkage and displacement of the wall rock, but larger plastic zones appear in their overhanging and concave parts. Ellipsoid-shape cavern has the best stability. Cylinder-shape cavern and cuboid-shape cavern have the poorest stability. In these two types of caverns, large deformations occur in the roof and sidewall, which pose a great potential of inducing collapse in the wall rock. By comparison of the stability characteristics in different positions of the wall rock, we found that the roof shape has a much greater influence than the sidewall on the stability of a cavern. The roof must be designed as an arch to improve cavern stability. Treatments to improve the stability of irregularly shaped caverns by changing operational pressure and utilization way or by modifying the caverns' shape are also discussed. So, this study not only determined the stability state of different shaped caverns for gas storage in bedded salt rocks, but also provides the ways to modify the irregular-shaped caverns for storage applications. INDEX TERMS Natural gas storage, bedded salt rock, cavern roof, cavern stability analysis, modifying cavern shape. II. CAVERN SHAPES AND SIMULATION MODEL A. SELECTION OF CAVERN SHAPES

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Tightness Analysis of Underground Natural Gas and Oil Storage Caverns With Limit Pillar Widths in Bedded Rock Salt

Cited by 45 publications

References 46 publications

Research on Mechanism and Control of Floor Heave of Mining-Influenced Roadway in Top Coal Caving Working Face

Research on Mechanism and Control of Floor Heave of Mining-Influenced Roadway in Top Coal Caving Working Face

Microscopic Pore Structure of Surrounding Rock for Underground Strategic Petroleum Reserve (SPR) Caverns in Bedded Rock Salt

Research on the Stability and Treatments of Natural Gas Storage Caverns With Different Shapes in Bedded Salt Rocks

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