砂泥互层地层断裂带结构特征及控油作用

通过露头区解剖、三维地震解释、测井曲线识别、岩心观察和薄片鉴定,对松辽盆地杏北油田葡萄花油层砂泥互层地层断裂带内部结构特征进行研究;建立基于测井曲线综合响应的断层破碎带厚度预测模型,进而探讨断裂带结构特征对断层边部剩余油富集和开采的控制作用。结果表明:断裂带由断层核和破碎带两部分组成,其中断层核发育泥岩涂抹的分段生长结构,破碎带发育破碎、滑动和变形3种特征;断层垂向上在葡Ⅰ4小层发生分段,造成系统取心井钻遇3个断点,其中断点1发育砂岩变形带的断层端部破碎带,断点2发育泥岩涂抹的主断层核,断点3发育泥质角砾岩和方解石充填泥岩裂缝的次断层核;断层面两侧随着距断层核距离增加破碎带微构造密度和碳酸盐含量逐渐降低。

Sandstone-mudstone interbed fault zones structure feature and controlling oil effect

By using outcrop dissection, 3-D seismic interpretation, logging curve comparison, core observation and rock thin section identification, we studied the internal structure of the fault zones in sandstone-mudstone interbed strata of the Putaohua reservoir in northern Xingbei Oilfield, Songliao Basin. Based on the comprehensive responses of well logging, a model to predict fault zone thickness was established; with it we discussed how the fault structure controlled the distribution and enrichment of remaining oil along the fault edges. Our results reveal that the fault zones are mainly composed of a fault core and the damage zones; the fault core develops segmented structure of shale smear, while damage zones show features of crushing, sliding and deformation; the fault segments vertically into PI4 stratigraphic horizon, causing the three breakpoints in the coring well drills, where breakpoint 1 develops fault tip damage zones of sandstone deformation band, breakpoint 2 develops the major fault core of shale smear, and breakpoint 3 develops argillaceous breccia and minor fault core of mudstone fractures filled by calcite. With increasing distance to the fault core, the density of minor fractures and carbonate content are gradually reduced.