Research on Seepage Field in Fractured Rock Mass of Underground Oil Storage Cave Using Distinct Element Method

2013 ◽  
Vol 353-356 ◽  
pp. 619-623
Author(s):  
Song Yu ◽  
Yun Peng Zhang ◽  
Wei Shen Zhu

The distribution of hydraulic pressure in fractured rock mass surrounding caverns after excavation and technique of stochastic generation of joint network are investigated based on discrete element method. In order to seal the oil in underground caverns with water in the actual engineering, a water curtain with water pressure is installed, and the changes of hydraulic pressure are simulated with a series of curtain pressures. It is shown that some joints that have been drained out during excavation can not be saturated if the water curtain pressure is less than a certain value. Water curtain pressure with a certain value gives a strong safe guarantee of saving oil in the underground petroleum storage caverns.

2013 ◽  
Vol 353-356 ◽  
pp. 1666-1670
Author(s):  
Yun Peng Zhang ◽  
Song Yu ◽  
Wei Shen Zhu

Based on joint statistics from the in-situ survey, using numerical simulation technique of joint network (Monte-Carlo method), the calculation model of fractured rock mass is generated. Underground seepage discharge filed in fractured rock mass surrounding storage caverns is analyzed by using distinct element method. The result of simulation has shown good agreement with surveying data. Two cases have been simulated that is water curtains is installed and is not installed. Water pressure distributions in joints are investigated in these two cases. It is shown that in the case without water curtain the groundwater in joints which locate the upper of underground caverns is drained out and water sealed conditions is completely unrealized. When water curtain pressure is set at 0.3MPa, can underground water seal the storage caverns.


2012 ◽  
Vol 594-597 ◽  
pp. 2569-2573 ◽  
Author(s):  
Yun Peng Zhang ◽  
Song Yu ◽  
Wei Shen Zhu

Underground seepage discharge field in fractured rock mass surrounding storage caverns is analyzed by using discrete element method and stochastic joint-generation method. Meanwhile water pressure distributions in joints are investigated with a series of curtain pressures and compared with no water curtain. In the case without water curtain the groundwater in joints which locate the upper of underground caverns is drained out and water-seal conditions are completely unrealized. When the water curtain pressure is less than a certain value, the joints that have been drained out can not be saturated, and only the water curtain pressure exceeds this certain value, can groundwater seal the storage caverns.


2012 ◽  
Vol 238 ◽  
pp. 814-817 ◽  
Author(s):  
Ji Chang Wu ◽  
Yu Min Zhang ◽  
Hong Xia Li

The jointed finite element method (JFEM) is used to analyze the deformation and failure characteristic of fractured rock mass and anchor reinforcement effect for the water collection shaft of the main power house of Dagangshan Hydropower Station. The results show that the JFEM not only simulates the actual rock mass structure very well, but also gives the reasonable simulation results for the common unstable rock mass. The JFEM may accurately simulate the major deformation characteristic and collapse mechanism, which is another effective way to analyze the stability of fractured rock mass. The on-site monitoring results show that the anchor reinforcement is effective for the water collection shaft


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Yongjian Pan ◽  
Huajun Wang ◽  
Yanlin Zhao ◽  
Qiang Liu ◽  
Shilin Luo

Water inrush and mud outburst are one of the crucial engineering disasters commonly encountered during the construction of many railways and tunnels in karst areas. In this paper, based on fluid dynamics theory and discrete element method, we established a fractured rock mass mud inflow model using particle flow PFC3D numerical software, simulated the whole process of fractured rock mass mud inflow, and discussed the effect of particle size and flow velocity on the change of pressure gradient. The numerical simulation results show that the movement of particles at the corner of the wall when the water pressure is first applied occurs similar to the vortex phenomenon, with the running time increases, the flow direction of particles changes, the vortex phenomenon disappears, and the flow direction of particles at the corner points to the fracture; in the initial stage, the slope of the particle flows rate curves increases in time, and the quadratic function is used for fitting. After the percolation velocity of particles reaches stability, the slope of the curve remains constant, and the primary function is used for fitting; the particle flow rate and pressure gradient are influenced by a variety of factors, and they approximately satisfy the exponential function of an “S” curve.


2014 ◽  
Vol 711 ◽  
pp. 566-570
Author(s):  
Wen Sheng Yu ◽  
Yang Ping

The connectivity of water curtain between holes must be known to ensure water seal effect of artificial water curtain system of the underground oil storage caverns. The permeability characteristics of the fractured rock mass is analysed based on packer test and validity test of the water curtain holes of the China's HuangDao’s national petroleum reserve underground water seal oil engineering, puts forward the connectivity judgment criterion of water curtain holes, and evaluate the connectivity of water curtain system of underground oil storage caverns. This criterion has been used in the connectivity evaluation of water curtain system of the HuangDao’s national petroleum reserve underground water seal oil engineering. Research provides a basis for the dynamic design of water curtain system of underground oil storage caverns, reduce project cost.


2012 ◽  
Vol 496 ◽  
pp. 538-541
Author(s):  
Zhi Qiang Kang ◽  
Wein Jie Li ◽  
Yu Bo Jia

Fractured rock mass, Hydraulic fracture, RFPA2D-Flow, Instability of the law. Abstract. Based on the theory of fluid-solid coupling, Studying on the effect of permeability about damage and stress, Analysis of influence factors what hydraulic fracturing process, fracture propagation pattern, and influencing factors including shape and magnitude of inlet hole, stress conditions, and specimen strength were investigated. Application of rock failure process analysis software coupled seepage-stress F-RFPA2D, numerical simulated rock water pressure to cause crack rupture instability process, research the fracture law of the rock on water pressure and vertical loading. Combine similar physical experiment model, contrast analysis of two broken results and stress-strain curve, reveals instability mechanical behavior of rock hydraulic fracture process. Obtain deep mining in the process of mine water seepage and water extrude, overburden rock crack up, expand, water seepage, water extrude, instability rupture process rules.


2012 ◽  
Vol 256-259 ◽  
pp. 547-551 ◽  
Author(s):  
Yong Xu ◽  
Wei Hong Peng

Considering the seepage stress coupling of fractured rock mass, the multiple holes grouting problems were simulated to analyse the spread regularity by Universal Distinct Element Code(UDEC).The results show that the correlation between grouting pressure and the diffusion distance is positive, whereas the correlation between ground stress and diffusion distance is negative; With the raising of grouting holes, the diffusion distance is increasing and becoming more uniform in all directions, and the grout pressure and saturation is falling and attenuation amplitude is decreasing along the direction of grout diffusion; With the increasing of fracture aperture, the grout diffusion distance is increasing, and the grout pressure and saturation attenuation amplitude is decreasing along the direction of grout diffusion.


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