WITSML casing plug Component Schema Valid values include: Balanced Cement Plug, Braidenhead Squeeze, Bridge Plug, Packer, Retainer, Squeeze. Used for all non-Bridge Plug Types. Valid values include: A, B, C, D, E, F, G, H, Other. The measured top depth of the casing plug. The measured bottom depth of the casing plug. Used for Balanced Plug Type. Used for all non-Bridge Plug Types. The item state for the item.