Fractures are effective seepage channels and storage spaces for oil, gas, and groundwater. Understanding the distribution characteristics of fractures can improve the efficiency of water production and the control of water-related geohazards in fractured aquifers. The development and distribution of natural fractures are usually controlled by paleotectonic stress fields. In this study, the data obtained from outcrop, cores, and thin sections were used to determine the development characteristics of such fractures. By doing an analysis of burial history, tectonic evolution, acoustic emission test, rock mechanics test, and conjugate joint analysis, two-dimensional (2D) heterogeneous geomechanical models were established by using a finite element method (FEM) stress analysis approach to simulate paleotectonic stress fields during the Indosinian, Early Yanshanian and Late Yanshanian periods. The effects of the variations of paleotectonic stress fields, hydrodynamic fields, structures, and rock mechanical parameters on the development of fractures could then be identified. A calculation model for the rock rupture rate was established to determine the quantitative development of fractures in different periods. Favorable areas for natural fracture development were determined by examining the relationship between the fracture linear density and pumping capacity of eleven wells. The simulation results indicate that the distributions of the maximum and minimum principal stresses and the maximum shear stress were nonuniform during the Indosinian, Early Yanshanian and Late Yanshanian periods, and high stress and/or low stress were mostly distributed in the fault and fold belts. During the Indosinian period, the tectonic and dissolution fractures were not developed. During the Early and Late Yanshanian periods, the tectonic and dissolution fractures were primarily developed around the fault and fold belts in the NNW-SSE and NWW-SEE directions. Those fault and fold belts are the locations with the greatest development of the natural fractures, which are also the main channels for the migration and accumulation of karst groundwater in the Ordovician formation in the Huainan coalfield. This study provides an important reference for the prevention and control of the Ordovician karst water damage in the study area, and proposes a new method for the prediction of fractured carbonate reservoirs.

裂缝是石油、天然气和地下水的有效渗流通道和储存空间。了解裂缝的分布特征可以提高产水效率和控制裂缝含水层中与水有关的地质灾害。天然裂缝的发育和分布通常受古构造应力场控制。在这项研究中，从露头、岩心和薄片获得的数据用于确定此类裂缝的发育特征。通过埋藏历史分析、构造演化、声发射试验、岩石力学试验和共轭节理分析，采用有限元应力分析方法建立二维（2D）非均质地质力学模型，模拟古构造印支期的应力场，燕山早期和燕山晚期。然后可以确定古构造应力场、水动力场、构造和岩石力学参数的变化对裂缝发育的影响。建立岩石破裂率计算模型，确定不同时期裂缝的定量发育情况。通过考察11口井的裂缝线密度与抽水能力之间的关系，确定了天然裂缝发育的有利区域。模拟结果表明，印支期、燕山早期和燕山晚期的最大、最小主应力和最大剪应力分布不均匀，高应力和/或低应力主要分布在断裂带和褶皱带。印支期构造和溶蚀断裂不发育。燕山早、晚燕山期构造和溶蚀裂缝主要发育在NNW-SSE和NWW-SEE方向的断裂带和褶皱带周围。这些断裂带和褶皱带是天然裂缝发育最大的部位，也是淮南煤田奥陶系岩溶地下水运移聚集的主要通道。该研究为研究区奥陶系岩溶水害防治提供重要参考，为裂缝性碳酸盐岩储层预测提供了新方法。构造和溶蚀裂缝主要发育在 NNW-SSE 和 NWW-SEE 方向的断裂带和褶皱带周围。这些断裂带和褶皱带是天然裂缝发育最大的部位，也是淮南煤田奥陶系岩溶地下水运移聚集的主要通道。该研究为研究区奥陶系岩溶水害防治提供重要参考，为裂缝性碳酸盐岩储层预测提供了新方法。构造和溶蚀裂缝主要发育在 NNW-SSE 和 NWW-SEE 方向的断裂带和褶皱带周围。这些断裂带和褶皱带是天然裂缝发育最大的部位，也是淮南煤田奥陶系岩溶地下水运移聚集的主要通道。该研究为研究区奥陶系岩溶水害防治提供重要参考，为裂缝性碳酸盐岩储层预测提供了新方法。也是淮南煤田奥陶系岩溶地下水运移聚集的主要通道。该研究为研究区奥陶系岩溶水害防治提供重要参考，为裂缝性碳酸盐岩储层预测提供了新方法。也是淮南煤田奥陶系岩溶地下水运移聚集的主要通道。该研究为研究区奥陶系岩溶水害防治提供了重要参考，并提出了裂缝性碳酸盐岩储层预测新方法。