What is the formula for calculating the extraction efficiency of geothermal wells?

Thermal extraction rate = (output temperature-injection temperature)/injection temperature × 100%. According to the inquired public information, the calculation formula of thermal extraction efficiency is: thermal extraction rate = (output temperature-injection temperature)/injection temperature × 100%. The calculation formula of thermal breakthrough time is: thermal breakthrough time = 1. 175× mu heat (material specific heat capacity)/(heat removal rate× heat loss coefficient )× (output temperature-injection temperature).