渤海湾盆地歧口凹陷南部沙河街组浊积扇储层综合预测

Comprehensive prediction of turbidite reservoir of Shahejie Formation in the south of Qikou Depression,Bohai Bay Basin

渤海湾盆地歧口凹陷南部古近系沙河街组发育一套湖相浊积扇沉积,砂岩储层以分布范围小、变化快、砂泥岩薄互层发育为特点。基于层序地层格架和储层成因类型的认识,利用纵向精细的测井资料和横向密集的地震资料,综合开展地震属性分析、测井约束反演和地质统计反演“三步骤”储层预测。研究表明:顺物源方向砂体呈前积叠置,分布较连续;而垂直物源方向,砂体分布变化快,多呈透镜状分布。受浊积扇南部断层下降盘的控制,南部砂体总体上较厚,浊积水道砂体也相对较厚。应用效果表明:地震属性分析、测井约束反演和地质统计反演“三步骤”储层综合预测技术比较适合稀井网、大井距条件下的储层精细预测。

A set of lacustrine turbidite fan deposit was developed in the Paleogene Shahejie Formation in the south of Qikou Depression,Bohai Bay Basin.The sandstone reservoir is characterized by small distribution range,rapid change and thin interbedding of sandstone and mudstone.Based on the recognition of sequence stratigraphic framework and reservoir genetic type,combined with the vertical fine logging data and lateral intensive seismic data,the“three-step”seismic reservoir prediction was comprehensively carried out,including seismic attribute analysis,well logging constrained inversion and geostatistical inversion.It is shown that sandbodies are superimposed and distributed continuously along with the direction of sediment source,but change rapidly and are mostly lenticular while being perpendicular to the direction of sediment source.Under the control of the footwall in the south of the turbidite fan,the sandbodies in the south are generally thick,and the turbidite channel sandbodies are also relatively thick.The application effect shows that the“three step”reservoir comprehensive prediction technology of seismic attribute analysis,well logging constrained inversion and geostatistical inversion,is more suitable for fine reservoir prediction under the condition of sparse well network and large well spacing.