Perforation 4 : A hole made through the casing and cement and into the formation. It has a characteristic entrance hole and penetration. It is the flow path from the formation to the wellbore in a cased and cemented completion
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}