Centek Bow Spring Centralizer Sub
The Centek Centralizer Sub is designed to be run as part of a tight tolerance casing string in deepwater, ultra-narrow annulus found in some of the world’s most challenging offshore fields.
The Centek Centralizer Sub is fitted with a close tolerance centralizer of either UROS-CT or TUR-CT design.
Centek Centralizer Sub Film - Video from Centek
In both options the Sub centralizer’s single piece construction eliminates the risk of failure associated with a welded bow to end band type designs. This, coupled with precise manufacturing, enables the centralizer sub to rotate within the centralizer at minimal torque values.
The unique interlocked band design means that the strength of the centralizer end-bands does not depend on quality or installer skill, but is as strong as the single piece of steel used in Centek’s centralizers. In addition, the weld pocket recesses are designed to ensure there is no need for a pronounced weld bead with the risk of friction grinding the bead down and weakening the weld.
Each sub centralizer is manufactured with minimal clearance to the casing and with a precisely formed cross bow curvature so that there are no “knife edges” (common among standard bow spring centralizers) which reduces the risk of subsea well head damage. Both the UROS-CT and TUR-CT versions can recess completely into the sub body during operation and so pass through the tightest of restrictions.
The sub body, manufactured to API 5CT requirements, will meet or exceed burst, collapse and tensile ratings and will be threaded to fit the casing string. Centek has the capability to supply sub bodies tailored to meet customer specifications.
Features and benefits
- Designed specifically for ultra-tight tolerance applications
- Low ECD (equivalent circulating density) signature to lower surge effect during RIH
- Allows for rotation when fully compressed
- Fewer bows for more efficient RIH
- Will meet or exceed host casing burst and collapse specifications
- Interlocked band design gives the strength of a single piece centralizer
- Ultra-narrow, close tolerance
- Alternative to standard subs that will have higher initial insertion forces due to bow design
Centralization and the ease of running casing is often a balance between strength and flexibility which combine to support, what we call, 'runability'. To help with product selection we've added a rating to all our products for flexibility, runability and inherent strength.
Centek Centralizer Subs are available from 9 5/8” through to 17 7/8”