Productivity Decline Due to Fines Migration (Modelling and Field Case Study)

High formation damage, including that induced by fines migration has been reported in numerous geothermal projects. The attaching electrostatic forces acting on fines are weak at high temperatures if compared with drag and lifting forces, which detach the particles from grain surfaces. Migration of lifted fines results in their straining in thin pores preferentially near to well, causing severe permeability and productivity decline. A mathematical model has been developed, based on recently developed theory of particle detachment in suspension flows. Solution for predicting well productivity is obtained. The model is validated by comparison with the field data from geothermal well A in Australia. Productivity decline due to fines migration is more likely to happen in high temperature geothermal reservoirs if compared with conventional aquifers or oil and gas fields.