高分辨率层序地层学在提高储集层预测精度中的应用

为了提高岩性一地层油气藏勘探阶段储集层预测精度,以高分辨率层序地层学理论为基础,划分和建立层序地层格架,据此进行速度场研究、地震反演、地震属性分析,进行储集层预测.以准噶尔盆地腹部石南21井区侏罗系头屯河组辫状河三角洲油藏为例,在高分辨率等时地层格架内进行构造变速成图和储集层预测.大大提高了储集层预测的精度.通过与实钻结果的对比,在目的层埋深约为2 500 m时,预测最大深度误差仅为10 m,平均相对预测误差仅为0.16%;平均有效砂岩厚度约为13 m的评价井,砂岩厚度预测误差最大仅为5 m.实践证明层序地层格架控制下的构造变速成图技术和储集层预测技术是提高储集层预测精度的有效技术.

Application of high-resolution sequence stratigraphy in improving the precision of reservoir prediction

On the basis of high-resolution sequence stratigraphy, this paper establishes a sequence stratigraphic frame, and predicts reservoirs by analyzing velocity field, seismic inversion, and seismic attributes. In the case study of the Jurassic Toutunhe Formation braided river delta reservoir of Shinan 21 well block, middle of the Junggar Basin, space variant velocity field inversion and reservoir prediction were carried out based on the sequence stratigraphic frame and the reservoir prediction accuracy was improved. Comparing the prediction results with the real drilling shows that, when the burial depth of bed of interest is 2 500 m, the maximum prediction error of depth is only 10 m, and the average relative prediction error is 0.16%; for appraisal wells with an average effective sandstone of 13 m, the maximum prediction error of sandstone thickness is only 5 m. The structure mapping and reservoir prediction constrained by the sequence stratigraphic frame achieved success.