Measurement of Hydrate-Bearing Sediment Impedance and Inversion of Hydrate Saturation

As a high-quality energy source, natural gas hydrate is widely distributed in sediment reservoirs. Compared with traditional resistivity methods, the electrical impedance method can more comprehensively explain the electrical properties of hydrate by obtaining parameters such as resistance and reactance, thereby accurately predicting hydrate saturation. This work systematically analyzed the effects of salinity and water content on the electrical impedance of porous media. Through the tetrahydrofuran (THF) hydrate formation experiment, the electrical impedance change law during the formation of THF hydrate in sediments and the influence mechanism of hydrate saturation on the electrical impedance properties of sediments were revealed. The prediction model based on XGBoost was used to achieve high-precision inversion of hydrate saturation (MSE = 0.00152, R2 = 0.9788) through electrical parameters (resistance, reactance) and sediment system parameters (water content, zeta potential, sediment type, and particle size).