The infiltration of fine particles into the reservoir and the resulting production decline has long been a problem to the petroleum industry. It is also generally accepted that formation damage due to particle plugging is not thoroughly understood. In contributing to the solution of this problem, an experimental study of more than 17 core plugs involving 25 linear runs has been conducted. The purpose was to study the different physical and mechanical aspects of the processes leading to formation damage caused by movement and entrapment of suspended particles (when chemical and other forces are minimized).
Permeability is a key parameter among several others that control reservoir performance. The experiments are based on the results of permeability decline in linear core tests.
Two methods of flood tests; constant flow rate and constant pressure drop, were used on Berea sandstone. Plastic particles were injected with ultra pure water as the transport medium. Essential filtercake properties required for the decline rate calculations were obtained.
Finally, particle characterization using the Coulter counter was analysed. The results combined with that of the filtercake properties were used to determine the mechanisms and extent of plugging.