Carbonate reservoirs are mainly fractured-caved reservoirs with very well-developed dissolved pores, fractures, and caves. They have strong heterogeneity with various types of reservoir pore spaces. Using seismic inversion and reservoir static characterization, the result shows that the fractured-caved carbonate rocks in China are mainly caves with poor connectivity and complex oil-water distribution. Large-scale dissolved caves are mostly discrete and isolated, while the fractures are complex and various. The fracture features are observed either as a single large fractures or as a local fracture network. The characteristics of fluid flow in fracture-caved reservoirs vary as a result of the different combinations of fractures and caves. Currently, the static characterization technology of fractured-caved reservoirs is influenced by the limited resolution of seismic data, leading to large interpretation errors. In contrast, the dynamic method is a more reliable and effective method to determine reservoir parameters. However, traditional seepage equations cannot accurately characterize the flow pattern of fractured-caved carbonate reservoirs. In the case of a single large-scale dissolved fractured-caved reservoir, oil wells are usually connected to large caves through large fractures or directly drilled into large dissolved caves. In this study, the large-scale dissolved caved reservoir is simplified into two cases: (1) a single-cave and single-fracture series model composed of a single-cave and a single-fracture and (2) a composite model of dissolved caves and surrounding fracture networks. Note that the flow in a large cave is considered as free flow due to its large scale. The flow in a large fracture connected to the cave is considered as flow through porous media, and the flow in the reservoir surrounding the fracture network is considered as multiple-porosity model seepage flow. The corresponding seepage-free flow coupling mathematical model of different fractured-caved reservoirs has been established on this basis. We also obtained the rate transient analysis type curves of the oil well, conducted sensitivity analysis of each parameter, constructed the corresponding rate transient analysis curves, analyzed sensitivities of each parameter, and finally designed a dynamic evaluation method of well and reservoir parameters for different types of fractured-caved carbonate reservoirs. This study extensively applies this method in the Halahatang Oilfield of China and evaluates parameters such as reservoir reserves and physical properties to provide rational guidance for developing fractured-caved carbonate reservoirs.

中文翻译：

---

复杂裂隙碳酸盐岩储层速率瞬变分析的理论研究与应用

碳酸盐岩储层主要是缝洞型储层，具有非常发达的溶解孔隙，裂缝和溶洞。它们具有很强的非均质性，具有各种类型的储层孔隙空间。通过地震反演和储层静态表征，结果表明，我国缝洞型碳酸盐岩主要为连通性较差，油水分布复杂的洞穴。大型的溶洞主要是离散的和孤立的，而裂缝则复杂多样。观察到的断裂特征要么是单个大裂缝，要么是局部裂缝网络。裂缝和溶洞的不同组合导致裂缝型储层中流体流动的特征发生变化。目前，裂缝性储层的静态表征技术受地震数据分辨率有限的影响，解释误差较大。相反，动态方法是确定储层参数的更可靠，更有效的方法。但是，传统的渗流方程无法准确地描述裂缝型碳酸盐岩储层的流型。对于单个大型溶洞裂缝储集层，油井通常通过大裂缝与大溶洞相连，或者直接钻入大溶洞。在这项研究中，将大型溶蚀溶洞储层简化为两种情况：（1）由单溶洞和单裂隙组成的单腔单裂隙级数模型和（2）溶蚀的复合模型洞穴和周围的裂缝网络。注意，大洞穴中的流动由于其规模较大而被视为自由流动。与洞穴相连的大裂缝中的流动被视为通过多孔介质的流动，裂缝网络周围的储层中的流动被视为多孔隙度模型的渗流。在此基础上，建立了相应的缝洞型储层无渗流耦合数学模型。我们还获得了油井的速率瞬变分析类型曲线，对每个参数进行了敏感性分析，构造了相应的速率瞬变分析曲线，分析了每个参数的敏感性，最后设计了不同类型油井和储层参数的动态评价方法。缝洞型碳酸盐岩储层。