Geology of Natural Gas in the Miyazaki Gas Field (Specially the weatern part of Miyazaki City)

Abstract

The natural gas of the Miyazaki gas field is of the water-drive type, reserved in the sandstone and conglomerate of the Tano formation. The chief source of the gas is Tano and upper formation, which contain a great deal of mollusks and foraminiferas. The permeability of reservoir rocks is low, but that calculated from the amount of lift water is high. The S.P. and R curves of the electric logs show that the rocks are compact and massive.
The reservoir rocks of this gas field, therefore, abound in fissures and cracks, with minor faults which resulted from folding.