Characteristics of Fan Delta Microfacies and Its Hydrocarbon Distribution in Anpeng Field

The microfacies feature of tight sandstone reservoir in fan delta of Anpeng oilfeidl in Biyang sag is studied on the basis of sedi- mentology, reservoir geology, logging geology and core data, combined with the recognition of sedimentary facies signs like sediment gran- ularity. The fan delta can be subdivided into two subfacies and three microfacies. The characteristics of deposits, petrophysical property and distribution of these microfacies are elaborated. The relationship between the microfacies and oil-gas distribution is analyzed. It is suggested that the mid-distal subaqueous distributary channel and channel-mouth bar are the favorable microfacies for oil-gas accumula- tion.