Conditions for shale gas accumulation and the gas-bearing factors of the Wufeng-Longmaxi formation in the Laifeng-Xianfeng area.

In this work, taking wells LD1, LD2, and LY2 in the Laifeng-Xianfeng area as the research target, through core description, intensive core sampling, experimental analysis, imaging logging and other methods, the characteristics of graptolite zone development, organic carbon content, mineral composition, shale reservoir properties and the gas-bearing properties of the Wufeng-Longmaxi Formation shale are systematically analyzed. The main factors affecting the gas-bearing capacity of the Wufeng-Longmaxi Formation shale are extensively evaluated. The results reveal the following: ① The Wufeng-Longmaxi Formation shale, which was deposited in a deep-water shelf environment, has a large thickness (50-60 m) and a stable distribution.

Damage and energy characteristics of coal rock combinations with inclined coal seams under axial loading.

A single load compression test of rock-coal-rock assemblages (RCRs) containing coal bodies with different inclinations was carried out with the research background of mining deep, large-steep coal seams. It was found that the larger the inclination angle of the coal body in the RCR samples, the larger the compaction stage of the samples and the smaller the uniaxial compressive strength value. In addition, both the maximum acoustic emission (AE) energy of the samples and the cumulative AE energy at the moment of destruction decreased with the increase of the inclination angle of the coal body in the form of exponential relativities.

Fracability evaluation of the middle-upper Permian marine shale reservoir in well HD1, western Hubei area.

Taking the HD1 well as the research target, through intensive core sampling, experimental test analysis, comprehensive logging interpretation and other methods, the fracability of shale reservoirs was discussed in this paper. The results show that the Gufeng-Dalong Formation in the HD1 well has a high organic carbon content, and the organic-rich shale developed in the lower part of the Gufeng and Dalong Formations with thicknesses of 30 m and 15 m, respectively. For the low-porosity and ultralow-permeability shale reservoir type, the natural fractures are undeveloped in the lower part of the Dalong Formation, with a lower linear density, while they are well developed in the Xiayao and Longtan Formations and the lower part of the Gufeng Formation, and the interlayer bedding fractures are relatively developed.