Permeability Characteristics Study of Fractured Hydrate-Bearing Sediments Based on 3D Printing

Natural and artificial fractures significantly influence the permeability of hydrate reservoirs, directly impacting the prediction of hydrate production capacity. Traditional laboratory permeability tests on reconstituted samples fail to effectively control the geometric features of the samples, and simple grid-based segmentation cannot replicate the complexity of real flow conditions. To address these shortcomings, this study introduces a method utilizing 3D printing technology to improve the sample preparation process in reconstitution tests. Additionally, a coupled flow-solid numerical model is developed to investigate the seepage characteristics of hydrate sediments under the combined effects of stress and geometric features. A viable alternative approach for studying the seepage characteristics of hydrate sediments is proposed: sediment analogs fabricated using 3D printing technology exhibit similar microstructures to sandy hydrate sediments and show good agreement in gas-phase permeability. The fracture distance significantly affects permeability, with an optimal distance for maximum permeability observed. For a given fracture dip angle, permeability is highest when the fracture distance constitutes 40% of the sample height. As the fracture dip angle increases, permeability shows a gradual increase.