Cementing the casing and liner in the oil and gas wells is an important and critical section of drilling operations. Particularly, as the conventional cements have a high range of density, cementing jobs in some cases such as in a low pressure, depleted, or highly fractured reservoir is so critical operation. The high density of slurry in the well could cause severe formation damage by its high column hydraulic pressure. Therefore, lightweight and ultra-lightweight cements would be the solution for these conditions. One of the innovations in ultra-lightweight cements designing is Foamed Cement. In the current book, an experimental approach for appropriate foamed cement designing (its slurry and set-cement characteristics) has been introduced. The vast information about casings and liners cementing and its process, drilling cements and their additives and standard procedures for various tests on these cements have been explained. The standard API and ISO tests for formulating a foamed cement for oil and gas wells cementing jobs have been described. Also, you can access the latest and cutting edge researches on oil and gas wells foamed cementing operations by reading this book.