iTOUGH2 Analysis of the Well Level Response to the Barometric Pressure Change (Well YZ-5, Kamchatka)

Abstract

We performed iTOUGH2 inverse modeling using a two-dimensional, radial model (cylindrical symmetry around a monitoring well) applied to Jan. 25, 2007 - Feb. 20, 2008 observational data of the water level monitoring well YZ-5 (Kamchatka). Before the inversion, the systematic component related to hydrogeological basin recharge/discharge conditionswere removed, and water level was converted into well fluid pressures. The atmospheric pressure change was specified as time-dependent Dirichlet boundary conditions at the well head and earth surface. Reservoir permeabilities (on the order of 10 3 mD) were identified as the most sensitive parameters, while porosity and compressibility are less sensitive. Moreover, the barometric pressure change mostly propagates into an aquifer directly through the well head, with pressure propagation limited to about one meter around the well.