Interference Test Analysis at the Takigami Geothermal Field, Japan

Abstract

A long term interference test was conducted under conditions of multiwell variable flow rate at Takigami for about ten months in 1987. The test data have been analyzed with an on-line analysis method on the basis of the linesource solution. This method employs Kalman filtering to process the data and then provides the best estimates of reservoir transmissivity and storativity when 3 new pressure data at an observation well becomes available. The pressure changes measured at seven observation wells have been analyzed with the present method using an infinite reservoir model. The data from one observation well have been further analyzed assuming a presence of a linear boundary. Performances of the parameters estimated for different reservoir models are compared. Fairly good estimates of reservoir parameters are obtained on the basis of an infinite reservoir model for two wells using the entire pressure data whereas for other five wells using a part of the pressure data.