Abstract: Based on the analysis of the heterogeneity of channel mouth bar reservoir, the horizontal variation function is given and matched by using the porosity data from the multi-directional horizontal wells. Combined with the variation function of vertical wells, it is considered that the statistic distribution of the delta front mouth bar reservoir parameter in horizontal direction is similar to that of reservoir parameters in vertical direction, and the variation functions are dominated by spherical model. The vertical range of vertical wells averages about 1.2 m, which represents the vertical thickness of single mouth bar; the plane long-axis range of horizontal wells ranges from 24 m to 36 m and the short-axis range of them ranges from 8 m to 16 m, which represent the length and width of single mouth bar, respectively. The ratio between the long-axis range and short-axis range is about 2:1～3:1; the ratio between the plane long-axis range and vertical range is about 20:1～30:1, and the ratio between the short-axis range and vertical range is about 6:1～13:1.

Key words: channel mouth bar, variation function, variogram, range, horizontal well