Deformation band development as a function of intrinsic host-rock properties in Triassic Sherwood Sandstone
Deformation band development as a function of intrinsic host-rock properties in Triassic Sherwood Sandstone
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三叠纪舍伍德砂岩中变形带发育与固有母岩性质的函数关系
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
R. Worden
中科院分区：
文献类型：
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作者：
J. Griffiths;D. Faulkner;A. Edwards;R. Worden
变形带显著地改变了砂岩储层的局部岩石物理性质，尽管砂岩的内在可变特征（例如粒度、分选和矿物学）如何影响变形带的性质和分布尚不清楚。为了解决这个问题，碎裂变形带内细，粗粒三叠纪舍伍德砂岩在Thurstaston，英国进行了分析，首次使用一套岩相学技术，露头研究，氦孔隙度和图像分析。粗粒砂岩中的变形带比下伏细粒砂岩中的变形带更丰富。当接近断层时，粗粒砂岩中碎裂带的北倾和南倾共轭组的密度（由数量/m2定义）大幅增加。显微组织分析表明，原生晶粒尺寸控制变形带密度。粗砂岩和细砂岩中的变形带导致孔隙度显著降低，因此可以代表侧向流体流动的障碍物或挡板。显微构造数据显示，在主岩和变形带内的钾长石颗粒优先碎裂。这项研究与近海几个含油气下三叠统储层的储层质量预测直接相关，因为变形带的发育发生在石炭纪烃源岩成熟和石油运移之前。
Abstract Deformation bands significantly alter the local petrophysical properties of sandstone reservoirs, although it is not known how the intrinsically variable characteristics of sandstones (e.g. grain size, sorting and mineralogy) influence the nature and distribution of deformation bands. To address this, cataclastic deformation bands within fine- and coarse-grained Triassic Sherwood Sandstone at Thurstaston, UK were analysed, for the first time, using a suite of petrographical techniques, outcrop studies, helium porosimetry and image analysis. Deformation bands are more abundant in the coarse-grained sandstone than in the underlying fine-grained sandstone. North- and south-dipping conjugate sets of cataclastic bands in the coarse-grained sandstone broadly increase in density (defined by number/m2) when approaching faults. Microstructural analysis revealed that primary grain size controls deformation band density. Deformation bands in both coarse and fine sandstones led to significantly reduced porosity, and so can represent barriers or baffles to lateral fluid flow. Microstructural data show preferential cataclasis of K-feldspar grains within the host rock and deformation band. The study is of direct relevance to the prediction of reservoir quality in several petroleum-bearing Lower Triassic reservoirs in the near offshore, as deformation band development occurred prior to Carboniferous source-rock maturation and petroleum migration.
影响因子：
3.1
作者：
Farrell, N. J. C.;Healy, D.;Taylor, C. W.
通讯作者：
Taylor, C. W.