Abstract: Nozzle-effect well apparatuses including nozzle-effect protectors, centralizers and stabilizers and related methods, the apparatuses having two or more blades or ribs extending outwardly from a body, the blades or ribs spaced apart further at one end of the apparatus than the other; in one embodiment, the wall thickness of the apparatus varying so that one end is thicker than the other or a portion or portions between the ends are thicker or thinner in wall thickness than other portions; in another embodiment, portions of valley areas between ribs or blades varying in size to create nozzle effects.

Abstract: Float equipment for well operations including float collars and plugs for use therein. In one embodiment a plug has a plurality of modular members so that a plug of desired dimensions and materials can be custom assembled for a particular job. Such a plug may include a plurality of modular wipers and spacers connected together with a plug top and a plug bottom with adhesives or connection means or both. Not only can such connection means provide an antirotation effect between adjacent plug components, but also combinations of lugs and recesses can achieve this. Also a plug is taught which can have a cavity therein with pieces of material for enhancing a plug's drillability.

Abstract: A reticulated centralizing apparatus and methods for its use. The apparatus has a plurality of pairs of collars or cages and a plurality of springs or bows connected to and extending between the collars or cages. The bows of one pair of collars pass over one collar of another pair of collars. The bows can be alternated singly or in groups and one pair of collars may have a certain number of bows different from the number of bows associated with another pair of collars.

Abstract: An apparatus and method for inserting flow control means into a well casing is disclosed. A receptacle having portions adapted to receive check valve means is mounted within said well casing and said well casing is inserted into a well. Check valve means may be pumped down into engagement with said receptacle to regulate the flow of fluid through the well casing. Alternatively, choke valve means may be pumped down into engagement with said receptacle instead of check valve means. The choke valve means may be constructed having portions adapted to receive check valve means so that check valve means may be pumped down into engagement with said choke valve means to regulate the flow of fluid through the well casing.