Assessing poroelastic properties of a geothermal reservoir by tidal signal analysis

•The Earth tides and atmospheric loading affect pressure of geothermal reservoirs.•Tidal signals can be utilized for estimating poroelastic properties.•The relationship between the poroelastic properties and the tidal effects is formulated and examined graphically.•Actual pressure data at an onshore geothermal field in Japan were analysed.