苏里格气田苏14井区盒8段层序地层格架中的沉积微相与砂体分布规律研究

鄂尔多斯盆地苏里格气田苏14井区上二叠统盒8段沉积特征与4个中期基准面旋回密切相关,盒8下亚段的MSC1、MSC2中期旋回主要发育基准面上升半旋回,为辫状河沉积;盒8上亚段2小层的MSC3旋回东部为上升半旋回,西部为非对称旋回,沉积相呈"东辫西曲"的格局;盒8上亚段1小层的MSC4旋回为对称旋回,主要发育曲流河沉积。这种沉积格局进而影响砂体分布,MSC1旋回和MSC2旋回砂体规模大,厚度大,横向连续性好;MSC3旋回东部砂体规模较西部大,横向连续性较好;MSC4砂体规模减小,厚度较薄,多呈孤立状,横向连续性差。

The Distribution Rules of Sand and Sedimentary Facies in the Framework of Sequence Stratigraphy of Ph 8 Member of Wellblock Su14in Sulige Gas-field

The sedimentary characteristics of Ph8 Member in Wellblock Su14of Sulige Gas-field in Ordos Basin were closely related to 4medium-term base level cycles.the MSC1and MSC2of the Ph8 Member were mainly dominated by base-level rising half cycle,the braided river deposits were mainly sedimentary bodies;the section of MSC3was rising half cycle,sedimentary phase was braided river in the east and asymmetric cycle was in the west,sedimentary phase was B meandering stream.The MSC4was a symmetric cycle,it mainly developed meandering river deposits.The sedimentary pattern would affect sand distribution.As a result,MSC1and MSC2sands are large-scale with big thickness and good lateral continuity;MSC3sand in east is larger and has better lateral continuity than that in the west,MSC4sand is at small-scale with less thickness,and it is isolated with poor lateral continuity.