缝洞型油藏连通单元地质建模研究——以哈拉哈塘油田为例

Three-Dimensional Geological Modeling of Connected Units in Crack-Vug Reservoirs:An Example of the Halahatang Oilfield

针对哈拉哈塘油田奥陶系裂缝孔洞型储层连通单元井组注水效果差异性很大的问题,开展缝洞单元连通井组地质建模研究。哈拉哈塘油田储集空间岩溶洞穴、孔洞、裂缝非常发育,类型形态多变,具有极强的非均质性,储层空间缝洞体识别及连通方式预测与定量评价难度大。本文首先利用地震识别的大型溶洞和蚂蚁体追踪的大尺度裂缝分布,通过确定性建模方法,建立离散大型溶洞模型和离散大尺度裂缝模型;然后在储层的波阻抗数据体和缝洞体储层构造模型的空间约束下,建立缝洞体连通单元的储层孔隙度模型,储层渗透率模型主要通过线性回归建立基质孔隙度、裂缝参数与渗透率关系,结合动态数值试井对静态回归计算的渗透率数值进行修正;最后利用曲率属性形象表征微裂缝,采用多属性协同模拟方法,建立多尺度离散缝洞储集体三维地质属性模型。该方法定量刻画了缝洞储集体在三维空间的展布特征,很好地表征了单元连通井组连通方式,为单元连通井组开发奠定了坚实的地质基础。

For the Ordovician crack - vug carbonate reservoirs in the Halahatang oilfield, the water injection effects are highly different between con- nected unit well groups. This work used the geological modeling to address this issue. The reservoirs in this oil field contain numerous cracks and vugs with strong heterogeneities both in vertical and lateral directions. So the recognition of cracks and vugs and prediction and quantitative evaluation of con- nection patterns are very difficult. Firstly, the large - scale rugs are recognized with seismic data and crack distribution is tracked with the ant - body method. Large - scale vug and large - scale crack models are then established by the deterministic modeling. With the spatial constraint of the wave im- pedance data and crack - cavity reservoir structure models, the reservoir porosity model of connected units is established. Through linear regression, the relationship between matrix porosity, crack parameters and permeability is determined and reservoir permeability model is established. Combined with dy- namic numerical well testing, the permeability model is corrected. At last, micro cracks are described with the curvature attribute. The muhiscale scatter crack - rug reservoir property models are established using the muhiattribute synergy analogy procedure. These approaches allow us to describe quantita- tively the three -dimensional space distribution of crack -vug reservoirs and characterize connection patterns of unit -well groups, which provide a theo- retical support for exploitation in such wells of the oilfield.