Numerical simulation of gas production from hydrate accumulations using a single horizontal well in Shenhu Area, South China Sea

Abstract

In 2007, gas hydrate samples were recovered during the scientific expedition conducted by the China Geological Survey in the Shenhu Area. It is expected that Shenhu will become a strategic area of gas hydrate exploitation in China. However, evaluation of the hydrate deposits in the area as a potential energy resource has not been completed. Based on currently available data from site measurements, it is possible to develop preliminarily estimates of the gas production potential by numerical simulation. The hydrate accumulations in Shenhu Area are similar to Class 3 deposits (involving only a HBL), and the overburden and underburden layers are assumed to be permeable. In this study, we estimated gas production from hydrates in the Shenhu Area using the depressurization method with a single horizontal well. The simulation results indicated that the hydrate dissociation occurs on the cylindrical interface around the well, and along the horizontal dissociation interfaces at the top and bottom of the HBL. The gas production rate in the Class 3 hydrate deposit at site SH7 in Shenhu Area is not suitable for commercial production using the depressurization method.