WellSim is an integrated geothermal wellbore simulator and analysis package designed to allow ‘what-if’ scenarios to be performed on a geothermal well, such as, ‘what might be the increase in production from choosing a larger casing diameter for future wells drilled in a field?’.

WellSim modules include:

  • Discharge test simulation, modelling the steady-state discharge of a geothermal production well at one mass flowrate.
  • Fluid composition and properties calculation for assessment of the consistency of measured fluid properties using up-to-date PVT model for the H2O-CO2-NaCl system.
  • Deliverability curve prediction by simulation of a series of discharge tests over a range of mass flowrates.
  • Statistical and graphical matching analysis of downhole pressure and temperatures, and deliverability curves.
  • Downhole measurement analysis (lower bound analysis) for assessment of errors and trends in downhole measurements, identification of feed zones and fluid composition.

The discharge test simulation module models liquid, two-phase, and superheated steam flow, including the effects of both dissolved solids (as NaCl) and non-condensable gases (as CO2). Both wellhead/down and deepest feed/up calculation can be made. WellSim also models secondary feed zones, and calculates fluid composition at secondary feeds, allowing linear, quadratic, or superheated steam type drawdown relationships to be specified at each feed for calculating feed mass flowrate.

The program allows multiple changes of casing and liner diameter and roughness, including deviated wells. Heat transfer with the surrounding rock formation and well casing can be modelled. Like all other geothermal software from Gradient GeoData, WellSim is fully unit-aware, which means that data can be entered, processed and presented in any measurement units.