Fines (silt and clay) migration has long been recognized as a problem in oil and gas wells producingfrom sandstone reservoirs. Core-test reports indicate that fines dislodge with high flow rates. In field tests, rapid production declines occur when wells are flowed above a critical flow rate. These phenomena are attributed to fines migration into the wellbore area caused by mechanical dislodgement rather than clay dispersion as a result of ionic shock. Formation fines can migrate during production and workover operations. During the production of oil or gas, fines can migrate once a critical flow rate is reached, when water encroaches the reservoir, or when two-phase flow (oil/water) exists. During workover or completion operations, fines migration can occur because of water-salinity changes or a large drawdown during a well test.
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