API Standard Rigid Casing Centralizers for Oilfield Drilling Use

Centralizers are an integral part of the cementing process. They provide the mechanism that centers the casing in the hole and allows uniform cement flow around the casing to help protect it at all points. Several styles of centralizers are available for matching different well specifications and hole sizes, including turbulence generating designs that help clean the annulus and distribute the cement more evenly and uniformly.

All models offer ample clearance for fluid passage and are extra effective in centering the casing, even in highly deviated holes and improve cement flow by reducing the effects of channeling.

Spiral Solid Rigid Centralizer

There are five or six spiral belt(straight belt). Streamlined grooves are between spiral belt (straight belt). In each belt, two or three alloy steel rollers with heat treatment are equipped. This type will be recomended as using in deviated well and horizontal well cementing.

Solid Body Centralizers

Steel or aluminum body construction.
Hinged and slip-on versions available.
Shock, impact, and corrosion resistant.
High tensile and yield strengths.
Available with straight or spiral blades.
Helps ensure positive centering in deviated or horizontal holes.
Helps prevent differential sticking while running casing.
Available for 2 1/8- to 30-in. Pipe.

Straight Blade Rigid Centralizers

Easy to install.
Less flow restriction than other centralizers.
Unaffected by lateral load.
Casing moves freely within the centralizer.
Reduces differential sticking and casing contact.

Spiral Blade Rigid Centralizers

Reduces gouging and scraping of formation.
Maximum wall contact.
Spiral blades allow better cement coverage.

Installation

Rigid centralizers can be installed on the casing with stop collars or with integral set screws. Installations that allow casing rotation and reciprocation are preferred because of improved displacement efficiency.

Most slip-on rigid centralizers must be installed between stop collars and are free floating there between. The new series centralizer is designed with an integral stop collar between the end rings.

This helps eliminate the risk of collapsing the centralizer assembly as it is forced through tight spots or high-drag sections of the wellbore.