In this study we analyzed five core samples from a hydrocarbon reservoir, the Matzen Field in the Vienna Basin (Austria). Deformation bands occur as single bands or as strands of several bands. In contrast to most published examples of deformation bands in terrigeneous sandstones, the reduction of porosity is predominantly caused by the precipitation of Fe-rich dolomite cement within the bands, and only subordinately by cataclasis of detrital grains. The chemical composition of this dolomite cement (10–12 wt% FeO) differs from detrital dolomite grains in the host rock (<2 wt% FeO). This observation in combination with stable isotope data suggests that the cement is not derived from the detrital grains, but precipitated from a fluid from an external, non-meteoric source. After an initial increase of porosity by dilation, disaggregation and fragmentation of detrital grains, a Fe-rich carbonate fluid crystallized within the bands, thereby reducing the porosity relative to the host sediment. The retention of pyrite cement by these cementation bands as well as the different degree of oil staining on either side of the bands demonstrate that these cementation bands act as effective barriers to the migration of fluids and should be considered in reservoir models.

中文翻译：

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油气藏中从膨胀到胶结带的变形带（奥地利维也纳盆地）

在这项研究中，我们分析了来自碳氢化合物储层的五个岩心样本，即维也纳盆地（奥地利）的 Matzen 油田。变形带以单带或多条带的形式出现。与大多数已发表的陆源砂岩变形带例子相反，孔隙度的减少主要是由带内富铁白云石胶结物的沉淀引起的，其次是碎屑颗粒的碎裂作用。这种白云石胶结物（10-12 wt% FeO）的化学成分不同于主岩中的碎屑白云石颗粒（<2 wt% FeO）。这一观察结果与稳定同位素数据相结合，表明胶结物不是来自碎屑颗粒，而是从外部非陨石源的流体中沉淀出来的。在通过膨胀最初增加孔隙率之后，碎屑颗粒的解聚和破碎，富铁碳酸盐流体在带内结晶，从而降低了相对于宿主沉积物的孔隙度。这些胶结带对黄铁矿胶结物的保留以及胶结带两侧不同程度的油污表明，这些胶结带是流体迁移的有效屏障，应在储层模型中加以考虑。