走滑构造差异变形特征及其主控因素分析——基于砂箱模拟实验

Differential deformation and its main controls on strike-slip structures: Evidence from sandbox experiments

李艳友 漆家福 周赏

Li Yanyou Qi Jiafu Zhou Shang

中国石油 东方地球物理勘探有限责任公司, 河北 涿州 072750 2. 中国石油大学(北京) 地球科学学院, 北京 102249 3. 中国石油 东方地球物理勘探有限责任公司 研究院地质研究中心, 河北 涿州 072750

BGP Inc, CNPC, Zhuozhou, Hebei 072750, China 2. College of Geosciences, China University of Petroleum, Beijing 102249, China 3. Geological Research Center, GRI, BGP Inc, CNPC, Zhuozhou, Hebei 072750, China

走滑断裂及其相关构造与油气聚集分布有着密切联系。受基底性质、断层形态及地层能干性影响，走滑断层具有明显分段特征，深、浅断裂组合样式也存在明显差异。利用砂箱实验讨论基底走滑断层形态、软弱层对盖层走滑变形带的影响。模拟实验表明：基底断层走滑位移量对盖层构造变形强度、构造变形样式有明显控制作用。地层岩性、盖层厚度控制浅层走滑剪切范围及变形幅度。走滑变形带宽度与软弱层厚度成正比，断层受阻部位软弱层厚度大则形成褶皱，反之发育断块构造。基底断层走向变化导致的局部应力条件差异是走滑断裂分段及构造变形差异的重要控制因素。

Strike-slip faults and associated structures have major influences on hydrocarbon accumulation and exploration. Pre-existing structures and the competence of sedimentary strata lead to differential deformation features and spatial distribution of strike-slip fault systems. The differential deformation of basement-involved strike-slip faults and the influence of incompetent layers on overlying layers were investigated using physical sandbox experiments. The displacement of basement-involved strike-slip faults controlled the deformation style and intensity of overlying layers. Lithology and cap rock thickness controlled strike-slip range and deformation intensity in shallow formations. The width of a strike-slip zone increased with incompetent layer thickness. Physical sandbox experiments showed that with contraction of strike-slip displacement, which kind of structural styles were formed, fold or fault block, was determined by the thickness of incompetent layer. The change of strike on basement fault caused extension or contraction stress fields. It is an important factor to control the segmentation of strike-slip faults and the differential deformation of vertical tectonics.

国家科技重大专项课题（2011ZX05009-001）资助。

https://doi.org/10.11781/sysydz201705711