Bed Filtration : A build-up of particles on the upstream side of a filter that improves the filter's ability to remove particles from fluid (will also raise the differential pressure across the filter)
George E. King Engineering, 5000 Oilfield Terms: A Glossary of Petroleum Engineering Terms, Abbreviations and Acronyms, US 2010. http://gekengineering.com/Downloads/Free_Downloads /Glossary_of_Petroleum_Engineering_Terms_25_August _2010.pdf, (Oil - Amer) {593}