少井条件下多源趋势融合技术在厚储层建模中的应用

Application of multi-source trend fusion in thick reservoir modeling with limited wells

河流相储层砂体横向变化快、叠置样式复杂、非均质性强,海上油田开发井数较少,井距较大,对井控部位的认识程度较低。为了准确反映砂体和储层参数在空间的分布,提出了多源趋势融合的物性建模方法。以东海盆地西湖凹陷D气田为例,首先将河道进行了精细划分,通过分级建模和基于目标的建模方法建立了沉积相模型;融合多源趋势,即平面位置分布趋势、垂向沉积韵律趋势和孔隙度敏感参数属性趋势等,建立了储层物性模型。从储量和生产动态两方面进行了模型验证,结果表明,本文方法储量拟合误差在10%以内,4口水平井生产动态模拟结果和实际较为吻合。本文方法有效地刻画了河道物性底部比顶部好,中部比边部好的地质效果,大大降低了储层参数分布的不确定性,对于开发井少、井距大的河流相储层,具有良好的应用前景。

As for fluvial reservoirs,where sand bodies have abrupt lateral variations,complex superimposition patterns,and strong heterogeneity,limited wells with huge spacing are adopted in the development of offshore oilfields,resulting in shallow knowledge of blocks under the control of wells.In order to accurately reflect the spacial distribution of parameters of sand bodies and reservoirs,the multi-source trend fusion modeling of physical properties has been put forward.With the D gasfield in the Xihu sag in the East Sea basin taken as an example,the fluvial facies was finely classified and used for the building of the sedimentary facies model based on hierarchical modeling and a target-oriented modeling method;furthermore,a reservoir physical property model was built through the fusion of multi-source trends,such as the plane position distribution trend,vertical sedimentary rhythm trend,and attribute trend of porosity as a sensitivity parameter.The model has been verified from two aspects of reserves and production dynamics,which suggests that with the method in this paper,the error of reserve fitting is within10%and the simulated results of production dynamics of 4 horizontal wells match well with the actual production data.This method,effectively depicting the fluvial physical properties with better performance at the bottom than on the top and in the middle than along the boundary and greatly reducing the uncertainty of reservoir parameter distribution,can be well applied in fluvial reservoirs with limited development wells and huge spacing.