Shear-enhanced compaction bands formed at shallow burial conditions; implications for fluid flow (Provence, France)
Shear-enhanced compaction bands formed at shallow burial conditions; implications for fluid flow (Provence, France)
复制标题
DOI：
10.1016/j.jsg.2012.11.008
复制
发表时间：
2013-02
影响因子：
3.1
通讯作者：
Grégory Ballas;R. Soliva;Jean-Pierre Sizun;H. Fossen;A. Benedicto;E. Skurtveit
中科院分区：
文献类型：
--
作者：
Grégory Ballas;R. Soliva;Jean-Pierre Sizun;H. Fossen;A. Benedicto;E. Skurtveit
对奥兰治地区（法国东南盆地）高孔隙度和渗透性砂岩的现场观察表明，剪切增强压实带网络可以在埋藏深度约 400 m ± 100 m 的收缩状态下形成。这些带显示出相等的压实和剪切位移，以共轭和密集分布的网络形式组织，并且仅限于粗粒（平均粒径为 0.6 ± 0.1 毫米）和较少孔隙（孔隙率为 26 ± 2%）砂层。这些带是破碎的微角砾岩，具有有限的颗粒粉碎和高颗粒微裂缝密度。它们显示渗透率 (mD) 降低范围从 0 到略高于 1 个数量级。它们显示出对与大气水流相关的蚀变产物没有控制，这表明这些剪切增强压实带对地下流体流没有影响或仅可以忽略不计。它们的选择性出现和在稠密层中传输率的小幅降低（20%）阻止了它们对砂岩储层的划分。与纳瓦霍和阿兹特克砂岩（美国西部）压实带种群的比较强调了埋藏深度和化学压实过程的存在对于变形带密封潜力的作用。
Field observations of highly porous and permeable sandstone in the Orange area (S-E Basin, France) show that networks of shear-enhanced compaction bands can form in a contractional regime at burial depths of about 400 m ± 100 m. These bands show equal compaction and shear displacements, are organized in conjugate and densely distributed networks, and are restricted to the coarse-grained (mean grain diameter of 0.6 ± 0.1 mm) and less porous (porosity of 26 ± 2%) sand layers. The bands are crush microbreccia with limited grain comminution and high grain microfracture density. They show reductions of permeability (mD) ranging from 0 to little more than 1 order of magnitude. They show no control on the alteration products related to meteoric water flow, which suggests that these shear-enhanced compaction bands have no or only negligible influence on subsurface fluid flow. Their selective occurrence and small (20%) reduction in transmissibility in densely populated layers prevented them from compartmentalizing the sandstone reservoirs. A comparison with compaction-band populations in the Navajo and Aztec sandtsones (western U.S.) emphasizes the role of burial depth and the presence of chemical compaction processes for the sealing potential of deformation bands.