Image log analysis of in situ stress orientation, breakout growth, and natural geologic structures to 2.5 km depth in central Scandinavian Caledonides: Results from the COSC‐1 borehole
Image log analysis of in situ stress orientation, breakout growth, and natural geologic structures to 2.5 km depth in central Scandinavian Caledonides: Results from the COSC‐1 borehole
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对斯堪的纳维亚喀里多尼亚中部 2.5 公里深度的原位应力方向、突破生长和自然地质结构进行图像测井分析：COSC-1 钻孔的结果
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
B. Almqvist
中科院分区：
文献类型：
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作者：
Q. Wenning;Théo Berthet;M. Ask;A. Zappone;J. Rosberg;B. Almqvist
斯堪的纳维亚喀里多尼亚深部科学钻孔中碰撞造山运动中应力引起的钻孔变形分析在瑞典中部一个特征较差的地区建立了原位应力方向。两次声学电视收视测井活动（两次活动之间间隔超过一年）提供了沿 2.5 公里深钻孔全长的详细图像，用于破裂、钻井诱发拉伸断裂 (DITF) 和自然发生的结构分析。沿总长度 22 m 的 13 个不同区域发生钻孔破裂，表明平均最大水平应力 SHmax，方向为 127° ± 12°。不常见的 DITF 被限制在 786 至 787 m 深度的一个区域内（SHmax 方向：121° ± 07°）。这些 SHmax 方向与斯堪的纳维亚半岛的总体趋势一致，并且符合许多产生地应力的机制（例如，山脊推力、地形载荷和地幔驱动应力）。两次连续采集图像记录可以分析随时间变化的井眼变形，表明六个破裂区已经沿井眼轴线和井眼周围径向蠕动。在岩心样品上测得的强动态模量和推断的弱原位应力各向异性抑制了破裂和 DITF 的形成。 800 m 以下的天然裂缝方向与拉伸或混合脆性剪切破坏一致，其趋势与当前 SHmax 相同。对图像测井中的叶理分析强化了这样的解释：在地震剖面中观察到的具有脉动倾角的不连续地震反射体是由于卧式折叠和布丁格造成的。
Stress‐induced borehole deformation analysis in the Collisional Orogeny in the Scandinavian Caledonide deep scientific borehole establishes in situ stress orientation in a poorly characterized region in central Sweden. Two acoustic televiewer logging campaigns, with more than 1 year between campaigns, provide detailed images along the full length of the 2.5 km deep borehole for breakout, drilling‐induced tensile fracture (DITF), and natural occurring structural analysis. Borehole breakouts occur in 13 distinct zones along total length of 22 m, indicating an average maximum horizontal stress, SHmax, orientation of 127° ± 12°. Infrequent DITFs are constrained within one zone from 786 to 787 m depth (SHmax orientation: 121° ± 07°). These SHmax orientations are in agreement with the general trend in Scandinavia and are in accordance with many mechanisms that generate crustal stress (e.g., ridge push, topographic loading, and mantel driven stresses). The unique acquisition of image logs in two successions allows for analysis of time‐dependent borehole deformation, indicating that six breakout zones have crept, both along the borehole axis and radially around the borehole. Strong dynamic moduli measured on core samples and an inferred weak in situ stress anisotropy inhibit the formation of breakouts and DITFs. Natural fracture orientation below 800 m is congruent to extensional or hybrid brittle shear failure along the same trend as the current SHmax. Analysis of foliation in the image logs reinforces the interpretation that the discontinuous seismic reflectors with fluctuating dip observed in seismic profiles are due to recumbent folding and boudinage.
斯堪的纳维亚喀里多尼德中部 2 5 公里深的 COSC-1 科学钻孔的 3D 反射地震成像
影响因子：
2.9
作者：
Almqvist;Berthet;Juhlin;Krauß;Rosberg
通讯作者：
Rosberg
COSC-1 - 在斯堪的纳维亚半岛古生代喀里多尼亚造山带中与俯冲相关的异地岩钻探
影响因子：
1.2
作者：
Lorenz;Rosberg;Juhlin;Almqvist;Berthet;Klonowska;Pascal;Pedersen;Roberts;N.W.W.
通讯作者：
N.W.W.