Float Collar & Casing Centralizer | How Are They Used?

 

Float Collar & Casing Centralizer | How Are They Used?

 

 

 

A casing centralizer is a mechanical device secured around the casing at various locations to keep the casing from contacting the wellbore walls. As a result of casing centralization, a continuous annular clearance around the casing allows cement to completely seal the casing to the borehole wall.

Definition of the Casing Centralizer

Casing centralization is one of the key elements to ensure the quality of a cementing job by preventing mud channeling and poor zonal isolation. Centralizers can also assist in the running of the casing and the prevention of differential sticking.

Applications

Centralizer’s usage is extensive! It is estimated that 10 million centralizers are manufactured and used every year globally. Centralizer manufacturers likely want to increase the demand for centralizers. However, operators, on the other hand, may wonder: “Should we use that many?”

WhileCasing Centralizer is used extensively, wellbore problems continue to arise due to poor cementing jobs. Centralizer properties and placements directly or indirectly affect the quality of the cementing job.

The challenge that both operators and service companies face is to choose the right type of centralizers and place the right amount at the optimum positions on the casing to achieve a good standoff profile.

What does Float Collar Mean? An Overview

A float collar is a special short coupling device that has threads installed generally after one, two, or three joints of casing from the float shoe. The float collar has a check valve, which allows the circulation of flow of fluid in only one direction. It only allows fluids to flow downward through the casing but not upward through the casing.

Float Collar Applications

Couplingdevices like the float collar are usually installed at the bottom of the casing string on which the cement plugs are joined during cementing operations. The primary role of a float collar is to prevent mud from entering into the casing while running in the hole, thereby making the casing float on the hydrocarbons at the bottom of the casing string. This reduces the weight and also prevents any backflow of cement during cementing operations. This is the place where the cementing bottom and top plugs land.

Types of float collars:

• Flapper valve type

• Spring-loaded ball valve type

These two are some of the crucial components required for cementing, and you may observe their extensive use in the relevant industry.