Quantitative Analysis of Flow Channeling Effect on the Exploitation of Geothermal Energy and One Possible Counter Method

The flow channeling effect is a well-known phenomenon in fractured rock masses, which has been intensively investigated for many years now, for various purposes and under different practical engineering backgrounds. Though it has remarkable impact on the exploitation of geothermal energy through fractured reservoir as well, there lacks systematic quantitative analysis on its influence. In the present work, we developed a series of general fracture networks with randomly distributed apertures and special fracture networks with artificial dominant flow paths (with some fracture networks of uniform fracture apertures as the base case), then we conducted conjugate heat transfer analysis considering heat recovery from rock formation in practical scenarios. Preliminary results show that the impact of channeling effect on the overall heat recovery capacity of a reservoir won’t take effect before a threshold injection flow rate, and the associated impact would enhance with increasing flow rates and the mean apertures of all fractures in the channeling flow path. What’s more, it’s not the case that the heat extraction performance of a reservoir would be weakened, as only those flow paths with limited heat supplements are harmful. Therefore, we also seek ways to detect those paths and try to eliminate their impact.