孔隙性砂岩地层中变形带研究述评

Review of research on deformation band in porous sandstone formations

变形带为孔隙性砂岩及沉积物中广泛发育的局部构造,也是断裂带主要的结构单元之一,可对流体的运移造成一定影响。在不同成岩阶段,纯净孔隙性砂岩地层中的变形带遵循解聚带、碎裂带、压溶胶结型碎裂带的形成顺序,层状硅酸盐变形带的形成则主要与岩石中层状硅酸盐矿物的含量有关。变形带完整的时间演化序列包括单条变形带、簇状变形带、节理和断层,不同类型变形带可出现叠加。变形带在三维空间的厚度、连续性及渗透性的变化是影响流体渗流的关键因素,对断裂带内部结构研究亦具有重要作用。不同变形带类型会造成油气的选择性充注。目前对于中国野外露头变形带的三维空间分布研究较为欠缺,受资料所限在含油气盆地内部至今无法有效识别覆盖区变形带。因此,深入研究变形带的发育特征及分布规律,可以更好地指导断层建模和流体运移分析。

Deformation band is a local structure widely developed in porous sandstones and sediments. It is one of the main structural units of the fault zone and can affect fluid migration. In different diagenetic stages,the deformation bands in pure porous sandstone follow the formation sequence of disaggregation band,cataclastic band and solution band,while the forma tion of phyllosilicate band is mainly related to the content of phyllosilicate minerals in the rock. A complete time evolution sequence of deformation bands includes single deformation band,clusters of deformation bands,joints and faults.Different types of deformation bands can superimpose. The variation of thickness,continuity and permeability of deformation bands in three-dimensional space is the key factor affecting fluid percalotion,and it is also important to study the internal struc ture of the fault zone. Different types of deformation bands will result in the selective filling of hydrocarbon. At present,the research on the three-dimensional spatial distribution of outcrop deformation bands in China is rather insufficient,and the deformation bands in oil-bearing basin cannot be efficiently identified so far because of the limitation of core and logging data. Therefore,an in-depth study of the development characteristics and distribution of deformation bands will be of great advantage to guide the fault modelling and fluid migration analysis.