Carbonate reservoirs in the Middle East hold a significant proportion of the remaining conventional oil reserves, which most of them were classified as naturally fractured. These reservoirs are well known for their low recoveries compared with their counterpart clastic unfractured reservoirs. Therefore, boosting their recoveries can assure to sustain the energy supply to the global oil markets. In this work, an example from the Middle East has been used to evaluate the impact of the fracture characteristics on the reservoir performance using four decades of production history. The characteristics of natural fractures have a remarkable impact on fluid flow behaviour in fractured reservoirs. Besides, these characteristics, such as fracture intensity, determines the matrix block dimensions, which in turn, influence the matrix recovery. However, it is challenging to estimate the fracture characteristics accurately due to the scarcity of the fracture data from subsurface measurements. Therefore, outcrop analogue data can be utilised to enhance the fracture modelling in fractured reservoirs and to fill the data gap between the seismic scale and well scale. In this work, we have integrated the outcrop fracture data with the core observations to improve the fracture modelling in the studied reservoir. Furthermore, a sensitivity study was carried out to investigate the impact of flow curves, gravity drainage mechanism, and its parameters, as well as the fracture storativity on the history matching in fractured reservoirs. Excellent matching results were obtained for the majority of the wells, as indicated by the low mismatch values. The obtained results highlighted the importance of fractures on the fluid flow behaviour, and hence the reservoir performance. Therefore, fracture properties should not be abusively modified using multipliers and local adjustment to avoid nullifying the reservoir characterisation efforts and degrade the simulation model capability for a future prediction.

中文翻译：

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卡姆楚察油藏裂缝特征对历史匹配的影响——以伊拉克为例

中东的碳酸盐岩油藏占剩余常规石油储量的很大一部分，其中大部分被归类为自然裂缝。众所周知，与对应的碎屑未压裂储层相比，这些储层的采收率低。因此，促进其恢复可以确保维持对全球石油市场的能源供应。在这项工作中，使用中东的一个例子来评估裂缝特征对储层性能的影响，使用了四个十年的生产历史。天然裂缝的特征对裂缝性储层中的流体流动行为有显着影响。此外，这些特性，如裂缝强度，决定了基质块尺寸，进而影响基质恢复。然而，由于地下测量的裂缝数据稀缺，准确估计裂缝特征具有挑战性。因此，可以利用露头模拟数据加强裂缝性储层的裂缝建模，填补地震尺度和井尺度之间的数据空白。在这项工作中，我们将露头裂缝数据与岩心观测相结合，以改进研究储层中的裂缝建模。此外，还进行了敏感性研究，以研究流动曲线、重力泄油机制及其参数以及裂缝储集性对裂缝性储层历史匹配的影响。如低失配值所示，大多数孔都获得了极好的匹配结果。获得的结果强调了裂缝对流体流动行为的重要性，从而对储层性能。因此，不应使用乘数和局部调整滥用修改裂缝特性，以避免使储层表征工作无效并降低未来预测的模拟模型能力。