| The ancient Zhujiang delta developed in Neogene Zhujiang Formation, Zhujiangkou Basin. In the southwestern Huizhou Sag and in the western Dongsha Uplift, the continuous sand bodies and the independent sand bodies developed on the delta front, and the latter is modified by waves or tidal currents. Considering the sand body type and tectonic setting, the lithologic reservoirs in Zhujiang Formation can be divided into three categories: monocline-uplifting type, mainly developed in a nasal tectonic zone on the flanks of Dongsha Uplift; anticline-uplifting type, mainly developed in the buried hill; and fault-uplifting type, mainly developed in the hanging wall of roll-over anticline or in the horst. The reservoir in Zhujiang Formation has a lower-generation and upper-storage pattern. Paleogene Wenchang Formation is a sufficient source-rock layer. The favorable tectonic setting and the transport system which is composed of fault, unconformity, permeable sandstone and structural ridge are the important conditions for the lithologic reservoirs in Zhujiangkou Basin. |
