Experimental Review: Particle clogging in porous sandstone geothermal reservoirs during tail water reinjection

Geothermal tail water reinjection (GTWR) is a worldwide conundrum that restricts the sustainable exploitation of porous sandstone geothermal reservoirs (PSGR). Particle clogging (PC) is the primary effect factor in the difficulty during GTWR of PSGR. It is valuable to clarify its influence factors and formation mechanism, which have not been summarized systematically. This review collated and synthesized the previous research on PC during GTWR in PSGR, and emphatically elaborated the influence mechanisms of hydrochemical and hydrodynamic parameters of the reinjection tail water on PC. The results indicate that the particle concentration, size, and temperature in the injected fluid positively correlate with the reservoir permeability damage. Meanwhile, injected fluid flow velocity, salt concentration, and pH all have critical values, and the reservoir permeability damage is the least when they are close to the critical values. Then, the PC mechanism during GTWR was comprehensively discussed, and recommendations for solving the PC problem during GTWR in PSGR were identified. Further, the reasons for the unsolved reinjection problem and some challenges in solving these difficulties including uncertainty problems, cross-scale correlation problems, multi-field coupling problems, and prediction of the clogging area were pointed out based on the current research. This review aims to guide the field reinjection operations, proposing further research directions in developing more effective reinjection on PSGR.

Automated summary

This review summarizes the problem of particle clogging during geothermal tail water reinjection (GTWR) and elaborates on its influencing factors and proposed solutions. It also identifies the unresolved issues and challenges in current research and suggests future research directions.