The gas reservoirs in the Upper Jurassic Penglaizhen Formation in the Xindu gas field, western Sichuan

The gas pools in the Upper Jurassic Penglaizhen Formation in the Xindu gas field, western Sichuan are believed to be the industrial gas pools consisting of a number of gas-bearing sandstone bodies. The favourable sedimentary microfacies is represented by channel mouth bar and submarine fan bar sandstones. The lithologies comprise fine-grained lithic sandstones and lithic quartz sandstones, which are relatively densed, with moderate to low porosity and permeability. The seismic response model for the gas-bearing sandstones displays the features of low frequency, high amplitude and low impedance, and the well-logs for the gas reservoirs exhibit the electrical properties of high AC, high resistance, low natural gamma-ray log, low neutron log and low density.