Distribution Features of Gas Hydrate Stable Zones and Resource Prediction of the Qiongdongnan Basin in the South China Sea

• Published in: Chinese Journal of Geophysics
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2004
• Subjects: General Medicine; Methane hydrate
• Online Access: http://dx.doi.org/10.1002/cjg2.519; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fcjg2.519; https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/cjg2.519

Abstract Oil and gas prospecting indicates plenitudinous occurrence and promising perspective of both biogenic and thermogenic gas resource of the Qiongdongnan basin in the South China Sea. Seismic sections show the occurrences of mud diapirs, gas‐filled zones, and faults that serve to connect gas‐filled zones and the seafloor. The blur zone in bottom water on the seismic section may suggest gas plume in seawater. These characteristics are comparatively propitious to hydrate generation. By using the thermodynamic method, we determine the distribution features of gas hydrate stable zones (GHSZ) and predict the possible locations of gas hydrate occurring near the seafloor in the Qiongdongnan basin. Biogenic methane hydrate is distributed in the subsurface where water depth is larger than ~600m, and has a GHSZ maximum thickness of ~314m, while thermogenic gas hydrate is distributed in the subsurface where water depth is generally larger than ~450m, and has a GHSZ maximum thickness of ~410m. The biogenic and thermogenic gas hydrate has a total perspective volume of ~10×109m3 with a hydrate gas volume of ~ 1.6 × 1012m3 in the Qiongdongnan basin.