Experimental Research on Acoustic Detection of Different Fracture Characteristics

Abstract

Fractures are important seepage channels and storage spaces in tight reservoirs, and are key geological information for exploration and development. Affected by complex tectonic actions, fractures mostly appear in the form of complex fracture belts, which makes it difficult to understand the way wave propagation is affected by the present of fractures with different fracture features. Therefore, we carried out physical experiments of scaled-down physical model wells based on acoustic logging and finite difference numerical simulation research, analyzed the relationship between different fracture characteristics and shear wave and Stoneley wave characteristics, and carried out the fracture width, number, and extensibility. quantitative characterization. The research results show that the amplitude of the direct Stoneley wave decreases exponentially with the increase of the equivalent fracture width. When the equivalent width of the fracture remains constant, the more the number of fractures, the greater the amplitude of the direct Stoneley wave; as the radius of the fracture extension increases, the relative amplitude of the Stoneley wave decreases, showing a logarithmic decrease.