Recording number of precursors from fourteen observation wells in Shanxi, Hebei, Beijing and Jiangsu region is analyzed and percentage of recording number of precursors to total number of earthquakes during the statis...Recording number of precursors from fourteen observation wells in Shanxi, Hebei, Beijing and Jiangsu region is analyzed and percentage of recording number of precursors to total number of earthquakes during the statistic years is presented, The relationship between characteristic parameters of well-aquifer system and responding ability to precursors is analyzed by the expression of amplification factor of well-aquifer system induced by Cooper et al. The results indicate that responding ability of well-aquifer system to precursors is related to inherent period of well aquifer, that is to say, the greater the inherent period is, the stronger the ability of recording precursor is. Re sponding ability of well-aquifer system to precursors is also related to ratio of transrnissivity to square of radius of wells, and the greater the ratio is, the stronger the responding ability is.展开更多
Based on linear poroelasfic and hydrogeology theory, a mathenmatical expression describing the relationship between water level clmnge and aquifer volume strain is put forward. Combined with earth tidal theory, we ana...Based on linear poroelasfic and hydrogeology theory, a mathenmatical expression describing the relationship between water level clmnge and aquifer volume strain is put forward. Combined with earth tidal theory, we analyze the response characteristics from well-aquifer water level change to earth tide of volume strain and present a method of volume strain inversion from water level clmnge. Comparing the results of inversion with real observed data, we found that there is a good consistency. This suggests that the method of volume strain inversion from water level clmnge is proper. It will offer a reference for learning about hydrogeology characteristics, volume strain and searching for precursor anomalies.展开更多
It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. Th...It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. The impacts of well conditions including temperature, pressure and shear rate, on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models. The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding. The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure, i.e., the viscosity flow activation energy(Eμ) gently increases with the increasing pressure. The viscosity–shear rate data are well fitted to the power law model at low temperature. However, due to the transition of fluid feature at high temperature(Newtonian fluid), the measured viscosity was found to slightly deviate from the fitting data. Combining the evaluated correlations, the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.展开更多
According to the in situ statistics data, indoor rock hydraulic fracturing experiments and numerical simulation results, the role of artesian water quantity was analyzed, emphasis was put on the analysis of the damage...According to the in situ statistics data, indoor rock hydraulic fracturing experiments and numerical simulation results, the role of artesian water quantity was analyzed, emphasis was put on the analysis of the damage mechanics of artesian water to rocks under the floor and the softening, solution and scouring action of artesian water were also researched. At the end of the paper, practical significance of similar material simulation to the influence of artesian water on water inrush under the floor was discussed and hoped to provide references to the artesian water hydraulics simulation experiment devices design and test based on the indoor similar material simulation platform.展开更多
Water temperature observation in wells,as a precursor observation project in China,aims to capture stress-strain information during the preparation of earthquakes. The study of the water temperature tidal effect has i...Water temperature observation in wells,as a precursor observation project in China,aims to capture stress-strain information during the preparation of earthquakes. The study of the water temperature tidal effect has important significance,for water temperature tidal effect is both a reflection of stress-strain in crust and an interference factor of precursor observations. With a view of thermal conditions in artesian wells,the paper holds that there are two mechanisms for interpreting tidally induced water temperature changes in artesian wells. Namely,thermal conduction mechanisms and thermal convection mechanism. The paper then derives the quantitative relationship between water temperature and tidal volumetric strain changes in an ideal artesian well. Finally,the water temperature tidal effect in the Benxi artesian well is analyzed. The results show that the water temperature tidal effect in Benxi well is the result of joint action of thermal conduction mechanism and thermal convection mechanism,in which thermal conduction mechanism plays a leading role.展开更多
基金Joint Seismological Science Foundation of China (103018).
文摘Recording number of precursors from fourteen observation wells in Shanxi, Hebei, Beijing and Jiangsu region is analyzed and percentage of recording number of precursors to total number of earthquakes during the statistic years is presented, The relationship between characteristic parameters of well-aquifer system and responding ability to precursors is analyzed by the expression of amplification factor of well-aquifer system induced by Cooper et al. The results indicate that responding ability of well-aquifer system to precursors is related to inherent period of well aquifer, that is to say, the greater the inherent period is, the stronger the ability of recording precursor is. Re sponding ability of well-aquifer system to precursors is also related to ratio of transrnissivity to square of radius of wells, and the greater the ratio is, the stronger the responding ability is.
基金The researchwas jointly supported by the research project entitled"Research on the Digital Data Analysis Application of Underground Fluid"under the 11th"Five-Year Plan"of China Earthquake Administration (2006BAC01B02-03-02)the Joint Earthquake Science Foundation of China Earthquake Administration (105141)
文摘Based on linear poroelasfic and hydrogeology theory, a mathenmatical expression describing the relationship between water level clmnge and aquifer volume strain is put forward. Combined with earth tidal theory, we analyze the response characteristics from well-aquifer water level change to earth tide of volume strain and present a method of volume strain inversion from water level clmnge. Comparing the results of inversion with real observed data, we found that there is a good consistency. This suggests that the method of volume strain inversion from water level clmnge is proper. It will offer a reference for learning about hydrogeology characteristics, volume strain and searching for precursor anomalies.
基金Supported by the National Key Science&Technology Projects during 13th Five-Year Plan(2016ZX05053-003)Young Scholars Development fund of SWPU(201499010121)
文摘It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. The impacts of well conditions including temperature, pressure and shear rate, on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models. The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding. The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure, i.e., the viscosity flow activation energy(Eμ) gently increases with the increasing pressure. The viscosity–shear rate data are well fitted to the power law model at low temperature. However, due to the transition of fluid feature at high temperature(Newtonian fluid), the measured viscosity was found to slightly deviate from the fitting data. Combining the evaluated correlations, the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.
文摘According to the in situ statistics data, indoor rock hydraulic fracturing experiments and numerical simulation results, the role of artesian water quantity was analyzed, emphasis was put on the analysis of the damage mechanics of artesian water to rocks under the floor and the softening, solution and scouring action of artesian water were also researched. At the end of the paper, practical significance of similar material simulation to the influence of artesian water on water inrush under the floor was discussed and hoped to provide references to the artesian water hydraulics simulation experiment devices design and test based on the indoor similar material simulation platform.
基金sponsored by the"Subsurface Fluid Observational Specification Research Program"(2060302-8-19),China
文摘Water temperature observation in wells,as a precursor observation project in China,aims to capture stress-strain information during the preparation of earthquakes. The study of the water temperature tidal effect has important significance,for water temperature tidal effect is both a reflection of stress-strain in crust and an interference factor of precursor observations. With a view of thermal conditions in artesian wells,the paper holds that there are two mechanisms for interpreting tidally induced water temperature changes in artesian wells. Namely,thermal conduction mechanisms and thermal convection mechanism. The paper then derives the quantitative relationship between water temperature and tidal volumetric strain changes in an ideal artesian well. Finally,the water temperature tidal effect in the Benxi artesian well is analyzed. The results show that the water temperature tidal effect in Benxi well is the result of joint action of thermal conduction mechanism and thermal convection mechanism,in which thermal conduction mechanism plays a leading role.
