Abstract:

The depositional characteristics of deepwater fan reservoir are a hot topic in petroleum exploration and development. With the analysis of the depositional characteristics of deepwater fan of the Lower Miocene Zhujiang Formation in the Liwan 31 Area, Baiyun Sag, Pearl River Mouth Basin, some suitable conditions for the deposition of deepwater fan are discussed. Sand enriched deepwater fan controlled by the tectonicsedimentary background were well developed in this area. The deepwater fan was the result of several kinds of hydrodynamic mechanisms which include debris flow, turbidity flow and bottom current that build gravity flow channels with complex lobes on the plane. On the basis of the deepwater fan pattern, a set of sedimentary microfacies classification scheme of deepwater fan (mainly consists of channels and lobes) is presented. Gravity channel, natural levee and slumping lobe are the primary reservoirs in the study area. The wideshallow incision gravity channels become narrowdeep, with the increase of the distance from sedimentary source. And the correlation of the depth of gravity channel is direct proportion to the width of natural levee.

Key words: deepwater fan with channel and lobe, hydrodynamic mechanism of deepwater fan, depositional pattern, gravity channel