Abstract: By using well logging curves, this paper analyses the relationship among strata information and all genetic signs as well as hydrodynamic factors in relevant sedimentary environment, studying well-logging facies, sedimentary microfacies, and the distribution and development of their reservoir sandbody. It also confirms that the underwater distributary channel microfacies and channel overlying debouch bar microfacies of delta front subfacies are favorable for developing low permeability reservoir sandbody in studies area. They can control the striking and distribution of sandbody and feature in fine continuity and connectivity, high thickness. The extension and scale of favorable areas of Chang3 and Chang 4+5 reservoirs can be controlled only if adequate trap conditions are available. Based on the predictive research on sedimentary microfacies and favorable petroliferous area of Chang33 2 reservoir, it reveals that the reservoir lies in the central and southwestern host facies of underwater distributary channel belonging to five water systems developed from northwest to southeast. The favorable petroliferous reservoirs controlled and blocked out by favorable sedimentary facies tend to be more upgraded from middle to the middle and lower reaches of southwestern part, blocking out the increasingly extending tendency of middle channel reservoir and southwest Huachi reservoir. All of this provides reliable geological foundation for future rolling and border expanding development for the reservoir in the area

Key words: well logging curve, extra-low permeability reservoir, sedimentary environment, sedimentary microfacies, favorable petroliferous area