Experimental research on the acoustic detection of different fracture characteristics

Fractures serve as critical pathways for fluid movement and storage within tight reservoirs, playing a pivotal role in the exploration and development of geologic resources. The intricate nature of these fractures, often manifesting as complex belts due to the influence of multifaceted tectonic activities, complicates the understanding of how wave propagation is altered by various fracture characteristics. To address this challenge, we carry out physical experiments and finite-difference numerical simulation studies on scaled physical models of wells based on acoustic logging techniques. This study meticulously examines the interplay between different fracture attributes and the behavior of the S and Stoneley waves, providing a quantitative analysis of the fracture width, density, and ductility. Our findings reveal that the amplitude of the direct Stoneley wave exhibits an exponential decline with an increase in the equivalent fracture width. With a constant equivalent fracture width, an increase in the number of fractures leads to a higher amplitude of the direct Stoneley wave. Moreover, as the radius of the fracture extension expands, the relative amplitude of the Stoneley wave diminishes, following a logarithmic trend.