Estimation of production characteristics curves of geothermal wells, using two performance inflow dimensionless reference curves

Abstract

In a previous paper were obtained numerically, inflow performance curves for mass productivity (IPR, lnflow Performance Relationships) and for thermal productivity (GIPR, Geothermal lnflow Performance Relationships) of geotherrnal wells. The IPR and GIPR curves relate the mass flow produced in geothermal wells with pressure and enthalpy of well flowing in the interface well-reservoir: The obtained curves cover a wide range properties of geothermal reservoir rock-fluid medium and its different explotation stages. Hypothetical reservoirs of pure water were considered, also reservoirs with carbone dioxide. Aditionally were proposed two dimensionless reference curves to estimate massic (IPR*) and energy (GIPR*) productivities of geothermal wells. In this paper a preliminary study on the applicability of both reference curves proposed is made, in order to estimate production characteristics curves of geothermal wells (relation pressure-mass flow rate at wellhead), from only one point (P, W) meassured at wellhead. The characteristics curves obtained from this procedure are compared with these meassured directly in the field. Finally matching the estimate IPR for a given well with IPR theoretical curves (Moya, 1994) is possible to determine the formation permeability in the wellbore.