Inter-crystalline pores, cavities, and fractures created from diagenetic shrinkage of dolomite are inter-connected each other, forming fine oil- and gas-bearing reservoirs. It is hard to predict these complex fracture...Inter-crystalline pores, cavities, and fractures created from diagenetic shrinkage of dolomite are inter-connected each other, forming fine oil- and gas-bearing reservoirs. It is hard to predict these complex fracture-cavity reservoirs because of their random distribution, different growth timing, and so on. Taking the lacustrine dolomite fracture-pore reservoir in the Lower Cretaceous Xiagou Formation in the Qingxi oilfield within the Jiuquan basin as an example, we put forward a comprehensive geophysical method to predict carbonate fractures.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
文摘Inter-crystalline pores, cavities, and fractures created from diagenetic shrinkage of dolomite are inter-connected each other, forming fine oil- and gas-bearing reservoirs. It is hard to predict these complex fracture-cavity reservoirs because of their random distribution, different growth timing, and so on. Taking the lacustrine dolomite fracture-pore reservoir in the Lower Cretaceous Xiagou Formation in the Qingxi oilfield within the Jiuquan basin as an example, we put forward a comprehensive geophysical method to predict carbonate fractures.
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.
