High-resolution borehole images and other well logs are used to study the interrelationship between mechanical stratigraphy and natural fractures in the carbonates of the Dehram reservoirs in the Zagros area, Southwest of Iran. Natural fractures are characterized for their vertical distribution and morphology in six nearby anticlinal structures hosting one of the largest gas provinces in the world. Mechanical stratigraphy is evaluated using dipole sonic and density data from the same boreholes in these six gas fields. This study shows that the effect of mechanical stratigraphy on the fracture system in carbonate reservoirs can be evaluated in two scales. Large-scale mechanical stratigraphy, represented by rock strength variations within units with more than 1-m thickness, influences the overall fracture intensity. At the same time, the effect of small-scale mechanical stratigraphy is more pronounced on aperture and continuity as two elements of the morphology of natural fractures. This scale of rock mechanics is practically discernible using high-resolution borehole images. Both scales of mechanical stratigraphy were crucial when building predictive models of reservoir performance in naturally fractured carbonate reservoirs.

高分辨率钻孔图像和其他测井记录用于研究伊朗西南部扎格罗斯地区 Dehram 储层碳酸盐中机械地层学与天然裂缝之间的相互关系。天然裂缝的特征在于它们在附近的六个背斜构造中的垂直分布和形态，这些背斜构造是世界上最大的天然气区之一。使用来自这六个气田中相同钻孔的偶极子声波和密度数据来评估机械地层学。本研究表明，机械地层学对碳酸盐岩储层裂缝系统的影响可以从两个尺度进行评估。以厚度超过 1 米的单元内岩石强度变化为代表的大尺度力学地层影响整体裂缝强度。同时，小尺度力学地层学对孔隙度和连续性作为天然裂缝形态的两个要素的影响更为明显。使用高分辨率钻孔图像实际上可以辨别这种岩石力学规模。在建立天然裂缝性碳酸盐储层储层性能预测模型时，两种力学地层尺度都至关重要。