Fracture scaling parameters are an important input for modelling of naturally fractured reservoirs, but are very difficult to derive from subsurface data. Extensive areas of exposure in the northern Kurdistan Region of Iraq provide useful outcrop analogues for nearby producing and potential hydrocarbon fields. A variety of data acquisition methods are used to analyse fracture systems in carbonates of the Upper Cretaceous Aqra–Bekhme Formation across a wide range of scales. When plotted on length–intensity graphs, the collated data lie below an upper envelope that follows a power-law distribution over five orders of magnitude between 0.1 and 3000 m, and which defines the maximum likely intensity of background fracturing across the region. Contouring the length–intensity data shows the distribution of intensities below the upper envelope, and allows modal and minimum likely intensities to be estimated. Likely causes for the observed variation in fracture intensities include the domainal nature of deformation, the proximity to high strain zones including faults, second-order effects such as ladder fractures, and variations in the thickness of mechanical layering. Thematic collection: This article is part of the Naturally Fractured Reservoirs collection available at: https://www.lyellcollection.org/cc/naturally-fractured-reservoirs

中文翻译：

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伊拉克东北部库尔德斯坦碳酸盐岩油藏单元的多尺度裂缝长度分析

裂缝缩放参数是天然裂缝性储层建模的重要输入，但很难从地下数据中推导出来。伊拉克北部库尔德斯坦地区的大面积暴露区域为附近的生产和潜在油气田提供了有用的露头类似物。使用多种数据采集方法来分析上白垩统 Aqra-Bekhme 组碳酸盐岩中各种尺度的裂缝系统。当绘制在长度-强度图上时，整理后的数据位于上包络下方，该上包络遵循 0.1 到 3000 m 之间五个数量级的幂律分布，并定义了整个区域背景破裂的最大可能强度。轮廓长度-强度数据显示了上包络线以下的强度分布，并允许估计模态和最小可能强度。观察到的裂缝强度变化的可能原因包括变形的域性质、靠近包括断层在内的高应变区、梯形裂缝等二级效应以及机械分层厚度的变化。专题合集：本文是自然断裂水库合集的一部分，可从以下网址获取：https://www.lyellcollection.org/cc/naturally-fractured-reservoirs