Distribution of gas hydrate stable zones and resource prediction in the qiongdongnan basin of the South China Sea

Abstract

Oil and gas prospecting in the Qiongdongnan basin of the South China Sea indicates the potential of plenitudinous natural gases. Seismic sections show the occurrences of diapirs and gas-filled zones that are communicated with seafloor through faults. The blur zones near seafloor on seismic section may suggest gas plumes in seawater. These characteristics are comparatively propitious to hydrate occurrence. A profile of gas hydrate stable zones across the basin slope is constructed by using thermodynamic prediction. Biogenic methane hydrates occur probably in the subsurface where water depth is larger than similar to 600m with similar to 310m of the maximum thickness, and thermogenic gas hydrates occur possibly on the subsurface where water depth is larger than similar to 450m with similar to 410m of the maximum thickness. The gas hydrate of similar to 10 X 10(9)m(3), and the hydrate gas of 1.65 x 10(12) m(3) are estimated in the Qiongdongnan basin of the South China Sea.