In this paper, the Chang 2 reservoir in Zichang Area of Ordos Basin, the second largest sedimentary basin in China, is classified and evaluated by using logging and core data, thin section identification and electron ...In this paper, the Chang 2 reservoir in Zichang Area of Ordos Basin, the second largest sedimentary basin in China, is classified and evaluated by using logging and core data, thin section identification and electron microscopy. The main sedimentary microfacies of Chang 2<sub>1</sub><sup>3</sup> is braided river delta sedimentary system in geological history, and there are three main sedimentary microfacies types: swamp microfacies, distributary channel microfacies and natural embankment microfacies on land. The heterogeneity in the study area is as follows: Chang 2<sub>1</sub><sup>2</sup> formation has the strongest heterogeneity, followed by Chang 2<sub>1</sub><sup>1</sup> formation with strong heterogeneity, and finally Chang 2<sub>1</sub><sup>3</sup> formation with medium heterogeneity. The reservoirs of Chang 2 member in the study area are dominated by III<sub>a</sub>, II<sub>b</sub> and III<sub>b</sub>, and the reservoirs are mainly composed of ultra-low porosity and low permeability reservoirs and low porosity and low permeability reservoirs.展开更多
文摘In this paper, the Chang 2 reservoir in Zichang Area of Ordos Basin, the second largest sedimentary basin in China, is classified and evaluated by using logging and core data, thin section identification and electron microscopy. The main sedimentary microfacies of Chang 2<sub>1</sub><sup>3</sup> is braided river delta sedimentary system in geological history, and there are three main sedimentary microfacies types: swamp microfacies, distributary channel microfacies and natural embankment microfacies on land. The heterogeneity in the study area is as follows: Chang 2<sub>1</sub><sup>2</sup> formation has the strongest heterogeneity, followed by Chang 2<sub>1</sub><sup>1</sup> formation with strong heterogeneity, and finally Chang 2<sub>1</sub><sup>3</sup> formation with medium heterogeneity. The reservoirs of Chang 2 member in the study area are dominated by III<sub>a</sub>, II<sub>b</sub> and III<sub>b</sub>, and the reservoirs are mainly composed of ultra-low porosity and low permeability reservoirs and low porosity and low permeability reservoirs.
