河口砂坝变差函数研究──以印尼某气田为例

A Study on Variation Function of Channel Mouth Bar——An example of a gas filed in Indonesia

在河口砂坝储集层非均质性研究基础上,利用多方向水平井孔隙度资料,求取并拟合了平面储集层变差函数。结合直井变差函数分析认为,三角洲前缘河口砂坝平面上储集层参数统计分布规律与垂向上分布是相似的,二者的变差函数都以球状模型为主。直井垂向变程平均为1.2m,代表了单个河口砂坝的垂直厚度,水平井平面长轴主变程为24～36m,短轴次变程为8～16m,分别代表了单个河口砂坝的平面长度和宽度,长轴主变程与短轴次变程比为2∶1～3∶1.平面长轴主变程与垂直变程之比为20∶1～30∶1,短轴次变程与垂直变程之比为6∶1～13∶1.

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-directlonal 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.