应用随机反演技术精细刻画河道砂体——以大庆油田萨北开发区萨二组为例

An Application of Stochastic Inversion Technique to Describe Channel Sandbody Subtly——Taking S-Ⅱ Layer of the Saertu Reservoir in North Development Area,Daqing Oilfield for Example

以大庆油田萨北开发区萨二组为例,研究了随机地震反演技术及其对河道砂体的精细刻画。研究表明:纵向上,不同厚度砂体的随机反演结果符合率差异较大:厚度大于3 m的砂体符合率为89.6%,厚度为2~3 m的砂体符合率为79.1%,厚度小于2 m的砂体符合率为71.5%;平面上,各沉积单元平均的砂体符合率能达到75%以上,且分流平原亚相的符合率要高于内前缘亚相。地震、测井及地质资料的充分结合,能够对河道的走向、复合河道砂体的单一河道边界及井间砂体叠置关系精细刻画,显示了井震结合预测河道砂体的适用性。

Take S-Ⅱ layer group in north development area of Daqing oil field as an example,it's studied that what is Stochastic inversion technique and its application to describe channel sandbody subtly. The study has shown that: In the vertical,there are large differences between the stochastic inversion results coincidence rate of sandbody of different thickness: The sandbody of over 3 metres,its coincidence rate is 98. 6%,; The sandbody of 2 ~ 3 m,its coincidence rate is 79. 1%; less than 2 metres,its coincidence rate is 71. 5%; in the plane,the average coincidence rate of all sedimentary units can reach more than 75%,and the coincidence rate of delta distributary plain subfacies is higher than that of inner front subfacies. With the logging curve and inversion results,combinating well and seismic the channel trend,the single channel sandbody boundary in compound channel sandbody and the superimposed relationship between interwell sandbody,can be described subtly.