A novel method for predicting geomechanical parameters of gassy sediments: Insights from theoretical models and laboratory testing

Abstract

The geomechanical properties of marine gassy sediments are significantly influenced by the presence of gas, which introduces challenges such as high acquisition costs and restricted applicability. Consequently, leveraging easily accessible data from operational marine areas to predict the geomechanical parameters is of substantial significance. In this study, a modified constitutive model of gassy sediments is established by incorporating the effects of physical properties and refining the calculation methods for parameters such as the elastic modulus. Numerical simulations are performed to assess the influence of both internal and external factors on the geomechanical parameters. Laboratory experiments are conducted to investigate the variation patterns of compressional wave velocity, compressional wave attenuation, cohesion, and internal friction angle across gassy sediments with different physical properties. By integrating theoretical analysis with experimental results, single-parameter models that correlate acoustic characteristics with physical properties and double-parameter models that relate geomechanical parameters to physical properties are developed. Ultimately, prediction models for geomechanical parameters based on acoustic characteristics is established. These advancements provide a simplified and effective approach for the rapid and precise determination of geomechanical parameters in gassy sediments, offering crucial theoretical and technical guidance for offshore petroleum exploration and field operations.