Relation between the Source Rock and Gas Volume in the Natural Gas (associated with Water) Field

Abstract

In the Mobara natural gas field the gas-water ratio rises greatly as the gas is removed from the well. This probably results from the fact that the free gas which is contained in the underlying Otadai formation and in the thick mudstone of the Kiwada formation rises through a zone fractured by. faults. It is necessary, of course, that there be good sand reservoirs for the gas, but the thick mudstone under the gas reservoir is thought to be the main source of the natural gas in the field.