Metamorphic buried hills are characterized as fractured reservoirs with immense potential for hydrocarbon exploration and exploitation. Identifying their effective reservoirs is crucial for prioritizing exploration and development efforts. However, current methods are inadequate for such reservoirs. In this study, we established a new evaluation method, the metamorphic reservoir quality index (MRQI), based on analyses of wallrock cores, cuttings, well logs, and test data in the Bozhong (BZ) 19-6 area. The MRQI method integrates three main control factors for the formation of metamorphic buried hill reservoirs, namely lithology, tectonism, and weathering. Our results indicate that exploratory wells in the BZ19-6 area have MRQI values ranging from 29.91 to 86.47, with average of 56.45, showcasing the wide distribution of metamorphic rocks with moderate reservoir quality. We also observed a significant increasing trend between fracture development and MRQI values, suggesting that MRQI can effectively characterize reservoir development. Moreover, individual well production displays an exponentially increasing trend with higher MRQI, with a clear turning point at MRQI of 65, representing the lower limit of an effective reservoir. Finally, we applied the MRQI method to classify the reservoir through depth in two exploration wells, demonstrating its effectiveness. The MRQI method enables quick and effective decision-making on exploratory and developmental projects in metamorphic buried hills. Hence, this method provides a valuable tool for reservoir management and enhancing the economic benefits of exploration and exploitation in such reservoirs.

变质潜山是一种裂缝性油气藏，具有巨大的油气勘探开发潜力。确定其有效储层对于确定勘探和开发工作的优先顺序至关重要。然而，目前的方法对于此类储层来说是不够的。本研究通过对渤中19-6地区围岩岩心、岩屑、测井和测试数据的分析，建立了一种新的评价方法——变质岩储层质量指数（MRQI）。 MRQI方法综合了岩性、构造作用和风化作用等变质岩潜山油藏形成的3个主要控制因素。结果表明，BZ19-6地区探井MRQI值为29.91～86.47，平均值为56.45，变质岩分布广泛，储层质量中等。我们还观察到裂缝发育程度与 MRQI 值之间存在显着的增加趋势，这表明 MRQI 可以有效地表征储层发育情况。而且，随着MRQI的升高，单井产量呈指数增长趋势，在MRQI为65时出现明显的拐点，代表有效油藏的下限。最后，应用MRQI方法对两口探井的储层按深度进行分类，验证了其有效性。 MRQI方法可以对变质潜山勘探和开发项目进行快速有效的决策。因此，该方法为油藏管理和提高油藏勘探开发经济效益提供了宝贵的工具。