2025/06/25 by Chenhe Zhang, Zhiqian Gao, Hui Lv +5 · 1 voice
Engineering · Earth and Planetary Sciences · #Hydrocarbon exploration and reservoir analysis #Geological and Geophysical Studies #Hydraulic Fracturing and Reservoir Analysis
paper · pdf · doi:10.2113/2025/lithosphere_2024_232
openalex publication_date 2025/06/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract The fluctuating dissolution of the water table, a key area of interest for paleokarst geologists, forms large karstic cavity reservoirs within horizontal runoff zones. Extensive research has been conducted to investigate the distribution models of reservoirs formed by water table fluctuating dissolution, focusing on the genesis and distribution of dominant karst fracture-cavity reservoirs within horizontal runoff zones. Reservoirs in the Yingshan Formation of the Tahe area were identified by integrating conventional logging, imaging logging, fault data, and paleogeomorphology. These reservoirs, formed by fluctuating erosion during three periods of water table development, exhibit certain features such as planar-aligned pores, near-horizontal dissolution fractures, caves, and various karst fabrics. Karst highlands and gentle slopes exhibited complete water table development across all three stages, whereas steep slopes developed them only in stages 1 and 2. Spatially, fracture-cave bodies can exhibit regional cross-strata and parallel-to-strata characteristics across the three stages. Under the influence of a single water table, karst highlands and gentle slopes with stages 1 and 3 water tables develop network fractures and cavity-fracture complexes that cross the strata, making them favorable for oil and gas exploration. Steep karst slopes with stage 1 water tables, as well as stage 2 geomorphologies (including highlands, gentle, and steep slopes), develop dissolution pores and near-horizontal fractures characterized by local development along the strata. With increasing depth from the weathering crust, large caves formed by multiple stages of faulting (levels I and II) and water tables fluctuating dissolution exhibit significant variations in filling materials. The caves associated with the stage 1 water table and fault interactions predominantly contain sandstone, sandstone-cemented collapse breccia, and collapse breccia, whereas those related to stages 2 and 3 feature mudstone and mudstone-cemented collapse breccia.