The centralizer significantly reduces frictional drag when used in deviated cased holes and it can provide approximately 100% standoff in cased-hole application.
Centralizer is a mechanical device that keeps casing from joining the wellbore wall. With a continuous 360-degree annular space around casing, it allows the cement to completely seal the casing to the borehole wall. Bow Centralizer is one of the types of centralizers which is an older and a common version of low-cost bow-spring centralizer design.
The casing is kept away from making further contact with the wall. Since, the centralizer’s continuous annular clearance around the casing allows cement to completely seal around the casing to the borehole wall. It is a well defined thing to say that each centralizer types and properties vary from each other. Also, the exact number of centralizers required and their placements on the casing are important to make it work properly.
Centralizer is mechanical device which is secured around the casing at various locations. Bow design of centralizer is a slightly larger design than the wellbore and they can provide complete centralization in vertical or slightly deviated wells. Since, they do not support the weight of the casing, it is very well deviated in wellbores.
Advantages Of Bow Design
The formed U-profile offers superior standoff which is more effective compared to the conventional bow-spring centralizers and enables efficient liner-hanger and packer settingProvides additional flow area to aid in mud removal which contributes to a high-quality primary cement jobSpecial locking tabs connect the bows to the end collars to achieve the highest restoring-force-to-drag ratio when run in hole in cased-hole applicationsOutstanding lateral resistance, flexible, nonweld design which is available on both slip-on and latch-on versions
Why Is Bow Centralizer Collecting More Popularity?
Since, earlier the entirely development of machines were low and the awareness was low as well. Now, on the other hand, because of digital media, the competition have increased and people have started to explore various features of machines. Bow Centralizer being used for casing the center of a wellbore or during a cement job, is a metal strip shaped like a hunting bow and attached to a tool or to the outside of casing.
This Bow design takes an efficient step towards quality cementing can lead to severe cementing problems including lack of zonal isolation and improper casing support for the lack of proper centralization. Bow Design allows the cement to be evenly distributed around the casing string. This is easy to assemble, time saver and availed with a strong grip.
Bow Centralizer increases fluid turbulence at the tool and helps to remove filter cake from the wellbore. This can be run through hole restrictions in the wellbore or through smaller casing strings that are cemented in the well. The better way to perform is a standoff analysis for each casing before a cementing job. Also, the exact number of centralizers required and their placements on the casing are important to make it work properly.