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生长断层由发育在上升盘或下降盘上的非封闭性断层面和封闭性剪切带构成。假定剪切带的性质与块体运动中塑性变形的软沉积物性质相同。岩心观察表明,剪切带组构类似瑞德尔剪切,并且随变形程度的增加表现为条纹状、锯齿状、共轭的和新月形的剪切。渗透率和孔隙度变化范围分别为0.1～0.01md和18％～8％。据有限的测试资料,初始压汞毛细管压力为400～550 psia,可形成平均油柱高98 m的圈闭。剪切带具有效封闭性,由于变形使原始沉积物均质化,并导致沉积物内小孔隙均匀分布。相反,断层面为拉伸区,具较高渗透性和低排替压力,使得油气从深处生油层运移到浅部圈闭。因此,生长断层既能在剪切带内形成封闭,又能沿断层面产生渗漏。剪切带可用倾角测井判别。剪切带倾角大小和方向均有变化,而与断层相邻地层的倾角由于正牵引作用显示较均一的模式。
The growth fault consists of a non-closed fault plane and a closed shear zone, which are developed on rising or falling plates. It is assumed that the nature of the shear band is the same as the plastic deformation of soft sediments during mass motion. Core observations show that the shear band structure resembles Riedel shear and appears as striped, jagged, conjugate and crescent shear as the degree of deformation increases. Permeability and porosity ranged from 0.1 to 0.01 md and 18% to 8%, respectively. According to limited test data, the initial pressure of mercury injection capillary pressure of 400 ~ 550 psia, the average height of the oil column can be formed 98 m traps. The shearing zone has an effective seal, homogenizing the original sediment due to deformation and resulting in a uniform distribution of small pores in the sediment. On the contrary, the fault plane is a stretching zone with higher permeability and lower displacement pressure, so that the oil and gas migrate from the deep oil layer to the shallow trap. Therefore, the growth fault can not only form a seal within the shear zone, but also produce leakage along the fault plane. Shear zone can be distinguished by dip logging. The shear band dip varies in magnitude and direction, while the dip of the formation adjacent to the fault shows a more uniform pattern due to positive traction.