Fines migration is the most common formation damage mechanism that challenges the economic viability of petroleum development projects. The phenomenon has been widely reported for production and injection wells, drilling, completion, waterflooding and pressure depletion with water support. It is explained by the lifting of reservoir fines, their migration and pore plugging with consequent permeability decline.
We introduce a maximum retention function for fines that models fines mobilization and allows coreflood interpretation, well impairment history analysis and well behavior prediction. The laboratory and field case studies presented validate the approach. The reservoir study presented shows how to use the coreflood- and well-history data for reliable prediction of productivity decline, its prevention, and mitigation.
The traditional view of fines migration is that it should be avoided because of its detrimental effect on reservoir permeability and hence well productivity. However, the permeability decline effect provides a relatively simple method for water mobility control. We show laboratory and field cases where, compared with “normal” waterflooding, the fines-assisted low salinity waterflood results in a significant increase in reservoir sweep due to fines lifting and permeability decline in the swept zone.
Additionally, in oil and gas reservoirs, the injection of a small fresh water bank into watered out wells, or above the hydrocarbon-water contact, decelerates the invaded water and significantly decreases water production. Huf-n-puf by low-salinity water significantly decreases water production in oil- and gas wells.
Reliable prediction of productivity decline due to fines migration and its effective management to enhance oil and gas production is the key message of this lecture.
This lecture stimulates the petroleum engineer’s thinking into productivity enhancement options and, in particular, that natural or deliberately induced fines migration may often assist in oil and gas production.