The development of fissures in expansive soils has a great effect on the stability of slope. Of the three phases of soils,the gas phase and solid phase are relatively insulated,so the average resistivity of soils can ...The development of fissures in expansive soils has a great effect on the stability of slope. Of the three phases of soils,the gas phase and solid phase are relatively insulated,so the average resistivity of soils can be calculated from the resistivity of the liquid phase. On this basis,the two-part model of resistivity changing with the water saturation of the expansive soil can be deduced. A 2-D resistance grid model is established based on simulating the resistance of ver-tically developed fissures. Variation in measured resistance of vertically developed fissures at different positions can be calculated from this model. Fissure development can be inversely determined from the variation in the measured resis-tance. Finally,the model is verified by an indoor resistivity test for remolded soil samples,indicating that the test result agrees well with that of the model established.展开更多
The Chaoyanggou oil field is a fractured low-permeability reservoir, where the distribution of oil and gas is controlled by the distribution and development of fractures.Based on outcrop, drilling core, thin section a...The Chaoyanggou oil field is a fractured low-permeability reservoir, where the distribution of oil and gas is controlled by the distribution and development of fractures.Based on outcrop, drilling core, thin section and log data, the development characteristics of fractures in this area are described.On this basis, the degree of fracture development was predicted by quantitative analysis of fracture strength and numerical simulation.The result shows that four groups of structural fractures, i.e., in near NS, and EW directions and in due NW and NE directions, were developed in the reservoir, with the nearly NS and EW fractures dominant, which are the along bedding decollement fractures formed by compressive folding action, while low angle shear fractures are related to thrusts.These fractures are mainly formed in the reversed tectonic stage at the end of the Mingshui formation during the Cretaceous period.The degree of fracture development is controlled by such factors as lithology, stratum thickness, faults, folds and depth.The fractures are developed with a clear zonation and are best developed in the northern zone, moderately developed towards the south and poorly developed in the middle zone.These prediction results are in good agreement with interpretation results from logs.展开更多
基金Project 50579017 supported by the National Natural Science Foundation of China
文摘The development of fissures in expansive soils has a great effect on the stability of slope. Of the three phases of soils,the gas phase and solid phase are relatively insulated,so the average resistivity of soils can be calculated from the resistivity of the liquid phase. On this basis,the two-part model of resistivity changing with the water saturation of the expansive soil can be deduced. A 2-D resistance grid model is established based on simulating the resistance of ver-tically developed fissures. Variation in measured resistance of vertically developed fissures at different positions can be calculated from this model. Fissure development can be inversely determined from the variation in the measured resis-tance. Finally,the model is verified by an indoor resistivity test for remolded soil samples,indicating that the test result agrees well with that of the model established.
基金Project 40772086 supported by the National Natural Science Foundation of China
文摘The Chaoyanggou oil field is a fractured low-permeability reservoir, where the distribution of oil and gas is controlled by the distribution and development of fractures.Based on outcrop, drilling core, thin section and log data, the development characteristics of fractures in this area are described.On this basis, the degree of fracture development was predicted by quantitative analysis of fracture strength and numerical simulation.The result shows that four groups of structural fractures, i.e., in near NS, and EW directions and in due NW and NE directions, were developed in the reservoir, with the nearly NS and EW fractures dominant, which are the along bedding decollement fractures formed by compressive folding action, while low angle shear fractures are related to thrusts.These fractures are mainly formed in the reversed tectonic stage at the end of the Mingshui formation during the Cretaceous period.The degree of fracture development is controlled by such factors as lithology, stratum thickness, faults, folds and depth.The fractures are developed with a clear zonation and are best developed in the northern zone, moderately developed towards the south and poorly developed in the middle zone.These prediction results are in good agreement with interpretation results from logs.
