Injection-Triggered Occlusion of Flow Pathways in Geothermal Operations

Figure 8

2D Darcy flow simulation grid for computing wellbore-centric velocity variations due to spatially correlated porosity distributions documented in Figure 4 for Klaipeda geological sections. The above-illustrated flow simulation shows the case for low-poro-connectivity parameter α~3 characteristic of the “deep filtration” assumption for particulate transport. In the present simulation particulates are transported arbitrarily distances into the surrounding rock. If the poro-connectivity parameter is given values in the range 15 < α < 30 widely observed in hydrocarbon reservoirs, then particulate transport is confined to the vicinity of the wellbore because most active flow channels become clogged with particulates; this case is illustrated in Figure 7(a). Figure 6 indicates that observed exponential injector decline at Klaipeda is consistent with near-wellbore occlusion rather than deep filtration occlusion.