110 likes | 136 Views
The bow centralizer is a simple device, slightly larger than the borehole. Read more http://www.zs-oilfieldequip.com/products/bow-spring-centralizers/<br>
E N D
A centralizer is a mechanical device that keeps well casing from touching the sides of the wellbore. This gives the drilling team a complete 360-degree space around the casing for applying cement or other completion materials.
In the drilling industry today, there are two kinds of centralizers used. One is bow-spring centralizer and the other, rigid blade design. The bow centralizer is a simple device, slightly larger than the borehole. It has spring mechanism which holds the pipe in place by applying pressure against the sides of the wellbore.
These are very helpful for running casing inside previous casing or openhole sections with extremely close annular clearances.
Advantages Of Using Bow-Spring Design: • Bows expand to provide excellent casing centralization in openholeor underreamedsections. • Bows recess completely into the tool body to allow passage through close tolerance sections and to protect the bows from damage.
These centralizers are available in float-collar, float-shoe and guide-shoe configurations to reduce the number of premium threads required in the casing string. • They provide reliability and durability during operations.
Due to the flexibility of bows, they can pass through narrow hole sections. • The shape and stiffness of the bows determine the restoring force, defined as the resistance force when a bow is compressed by 1/3 of its uncompressed height.
Since the bow springs are slightly larger than the wellbore, they can provide complete centralization in vertical or slightly deviated wells.
The downside to the bow-spring design is that it does not support the weight of pipe very well. When the casing is heavy and/or the wellbore is highly deviated, they may not support the casing very well.
The effectiveness of this type of centralizer is heavily dependent on the restoring force.
Zhongshi Group Co.,Ltd. Tel: 0086-371-87096210 0086-371-87096211 Fax: 0086-371-87096212 Email:sale@chinajixie.com Website : http://www.zs-oilfieldequip.com/