Nonisothermal Injection Tests in Fractured Reservoirs

Abstract

Pressure transient tests are conducted on geothermal wells in order to obtain data that can be used to calculate the transmissivity (permeability-thickness product) and the skin factor of the well. Various tests can be used to obtain pressure transient data, including pressure drawdown, build-up, injection and falloff tests, and interference tests. Here we are concerned with the analysis of nonisothermal injection and fall of f test data. data from pressure transient tests are commonly interpreted using conventional type-curve or graphical analysis, which usually assunes isothermal fluid flow in porous media. geothermal reservoirs, these tests are complicated by nonisothermal behavior, fractures, and the presence of multiple fluid phases. injection and fall of f tests are often favored for the analysis of two-phase reservoirs, because they eliminate the need for assuming relative permeabilities for vapor and liquid phases; these factors are unknown at present.