茂原ガス田の産出挙動と毛細管圧力の関係について
1992 年 57 巻 2 号 p. 151-156
詳細
1992 年 57 巻 2 号 p. 151-156
The reservoir of the Mobara gas field is restricted to the Kazusa group which is a sedimentary basin made up of sandstones and silty mudstones alternately. It was understood that the Mobara gas reservoir is a dual porosity type. We developped a mathematical model that is useful in simulating the Mobara type performance.
Most of the gas generated in the mudstones is dissolved in the brine reserved in the both rocks. A little of the gas is distributed as discontinuous globules due to pore throats in the silty mudstones.
The bubbles begin to move toward the sandstones when the formation pressure has been reduced. In this mechanism the rock properties are important, especially relative permeability and capillary pressure. Because the mobility of gas phase becomes better by far as compared with that of water phase, the gas water ratio increases continually.
