Knowledge about subsurface geological characteristics and a geothermic genetic model plays an essential role in geothermal exploration and resource assessment. To solve the problem in the Shunping area along eastern Taihang Mountain, geothermal geological conditions were analyzed by geophysical, geochemical, and geological methods, such as magnetotelluric, gas geochemistry, and structural analysis. The geothermic genetic model was developed by analyzing the characteristics of the heat source, water source, migration channel, reservoir, and cap rock of the geothermal geological conditions. Favorable deep thermal conduction conditions and sufficient atmospheric precipitation in the study area provide an original heat source and water supply for geothermal formation. The faults and unconformities of different scales have become effective channels for the migration of underground hot water. The thermal reservoir formed by marine carbonate rocks with karst fissure development provides suitable space for the storage of underground hot water. Although the Cenozoic strata have good thermal insulation and water insulation function, the thermal insulation and water insulation effect is not ideal because of the shallow coverage in the Shunping area and the damage by tectonic action, which affected thermal insulation and water insulation to some extent, restricting the practical preservation of underground heat energy in the Shunping area. The bedrock geothermal resource in the Shunping area is original from the combined action of multiple indexes of source, transport, reservoir, and cap. The geothermal geologic conditions of source and reservoir in the Shunping area are very similar to those in the Xiongan new area, and have obvious advantages in hydrodynamic conditions. Although limited by the cap’s effectiveness, the geothermal resources in the Shunping area can provide some clean energy support for local production and life, thereby satisfying economic development conditions and encouraging further geological exploration.

Strike-slip faults and their associated fractures in the ultra-deep marine carbonate reservoirs of the Fuman Oilfield, Tarim Basin, hold significant petroleum geological importance, with the developmental characteristics of fractures being a key factor controlling reservoir productivity. This study targets the F_I17 strike-slip fault zone within the oilfield, where a comprehensive evaluation of fracture effectiveness was performed by integrating geological methods, including core and thin section observation, fluid inclusion thermometry, geophysical fracture identification approaches using imaging logging and seismic data, and geomechanical simulations. The results showed that: (1) structural fractures were developed in at least three stages, predominantly high-angle fractures with their strikes obliquely intersecting the main fault at a small angle, and were affected by multiple episodes of fluid activity, while early-phase fractures exhibited severe filling whereas late-phase fractures had good effectiveness; (2) ultra-deep carbonate rocks contained well-developed stylolites, with extensive horizontal stylolites reducing fracture effectiveness; (3) mechanical effectiveness evaluation parameters were proposed by integrating normal stress, shear stress, and formation pressure, with slip tendency as the dominant indicator, and referenced to the leakage factor and dilation tendency to characterize fracture effectiveness; (4) dynamic effectiveness was assessed using closure/opening pressures, defining a reasonable formation pressure range for hydrocarbon exploitation. The findings of this study can provide theoretical guidance for the further exploration and development of ultra-deep reservoirs in the Fuman Oilfield.

As the main field for crude oil exploration in the western of the South China Sea, the Weixinan Sag, Beibuwan Basin, has discovered multiple hydrocarbon-bearing structures. Carboniferous carbonate buried-hills in the Weixinan Sag, as a new field for increasing oil reserves and production, have enormous potential for exploration. Due to the influence of karstification, carbonate buried-hill reservoirs exhibit strong heterogeneity and rapid changes in physical properties, making the exploration of effective reservoirs more difficult. In this study, drilling cores and resistivity imaging logging data were employed to investigate the petrological characteristics and fracture development patterns of buried-hill reservoirs. By processing and calculating well logging curves, the development characteristics and vertical distribution patterns of karst in buried-hill reservoirs can be effectively displayed. Based on this, divide karst facies zones, measure karst thickness, and analyze their distribution patterns. The results indicate that tectonic activity is the main controlling factor for the karst differences in carbonate buried-hills in the Weixinan sag. the carbonate buried-hills karst in the No. 1 and No. 2 fault zones has characteristics of vertical zoning, plane partitions, and multiple phases. The buried-hills in the No. 1 fault zone have more karst stages and effective karst storage space than the buried-hills in the No. 2 fault zone. We propose four karst types under the control of tectonic activities, and establish a development model for the karst in the Weixinan Sag buried-hills. This study provides significant guidance for the development and reservoir prediction for similarly carbonate buried karst hills.

Based on the three-dimensional seismic dataset, we consider a key area in Beibuwan Basin, South China Sea, combined with quantitative analysis method, in order to define the features of transfer zone, and its temporal spatial development mechanism is revealed. The two boundary faults in the study area constitute an S-type fault system which does not connect. During the Paleogene rifting, the fault systems and Structuralstratigraphic characteristics between Eocene and Oligocene rifting sequences are different, the ways and quantities of transfer displacement are also distinctly different: (1) The two-phase of Eocene and Oligocene generally developed transfer zones, which were controlled by the structure background and boundary conditions, the formation mechanism of the transfer zone was different in time and space, the distribution of the transfer zone was distinctly different; (2) The Ailaoshan-Honghe strike slip fault, the extension derived from the expansion of the South China Sea have a significant impact on the transfer zone formation and characteristics. The segmented growth of the fault has a direct impact on the formation of the transfer zone. This study reveals the formation mechanism of the transfer zone of superimposed basins in China offshore, which is beneficial to hydrocarbon accumulation in Eocene and Oligocene sequences.