**7. Conclusions**

The author has developed an approach to estimate reservoir productivity under severe schedule limitations. Such limitations can originate from limited access to sites for drilling and well testing under snowy and mountainous conditions. To make the most of the limited time available, the new approach progresses in parallel with the conventional standard approach with an inverse approach using the transient responses observed while performing production tests, which are referenced in the final step of the standard approach. Combining these approaches, estimates of reservoir productivity can be rapidly generated. This feature is of value to successfully manage explorational and developmental projects.

Assuming a practical geothermal field, the author has demonstrated the procedures of this new approach. The procedures are straightforward: the pressure interference is simulated at the monitoring wells, the production and reinjection rates are simulated by combining the wellbore and reservoir models, then future operational scenarios are forecasted. By defining surveyed and unsurveyed regions, the reservoir model strictly divides the simulation period into an earlier period constrained by observations through the parameters in the surveyed region and a later period with no constraints. Performing a number of trial runs while randomly selecting permeability values in the unsurveyed regions, we can obtain frequency distributions for estimates of the reservoir productivity and successfully make project management decisions.
