The remaining oil potential is great in the delta front in the first sand group of the 1st Member of Funing Formation
of the Wei-5 fault block，but the distribution of the remaining oil is not clear. With such data as the core，well logging，
dynamic monitoring，the architectural characteristics of the delta front sand body and its relations with the distribution of
remaining oil were studied. The results show that among the six recognized orders of bounding surface，the forth order bounding
surfaces is crucial to the distribution of remained oil within the layer. Eight facies architectural elements，bounded by the fourth
order bounding surface，are identified. Studies found that the configuration of single architectural element and seepage flow
differences between elements control the remaining oil distribution. Areas with rich remaining oil can be divided into rim area
and isolated area. Rim areas are mainly distributary channel endings or lateral margin edge，mouth bar lateral margin，and
natural levee，sand sheet and distal bars. Isolated areas enriched with remaining oil are mainly lenticular sand bodies，such as
mouth bar and distal bar，which is not connected with the underwater distributary channel.
