Centek introduces Deep Water Inter Casing Centralizer Sub
Centek is launching its Inter Casing Centralizer Sub (ICCS), designed to be run as part of a tight tolerance casing string in deepwater, ultra-narrow annulus applications.
Centek and Halliburton collaborated in developing the ICCS. The body of the centralizer sub is machined to Centek and Halliburton’s exacting standards. Centek’s patented UROS (Under Reamed Offset Bow) centralizer technology is installed on the sub body by Halliburton in a process that complies with the toughest quality control standards. The sub body, manufactured to API 5CT requirements, meets or exceeds all burst, collapse and tensile ratings. The UROS centralizer gives optimum restoring performance with minimal starting and running forces when passing through the tightest restrictions.
Computer visualization of the ICCS
Photograph of the ICCS
The centralizer is designed and 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. Crucially, during operation the centralizer can recess completely into the sub body and so pass through the tightest of restrictions while protecting the bows from damage.
The centralizer’s single piece construction eliminates the risk of failure associated with welded bow to end band type designs, and 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.
“Centek appreciates the need for a close tolerance centralizer for use in very tight annulus applications, where the margins between pore pressure and the fracture gradient are narrow,” said Cliff Berry, Vice-President, Global Business Development at Centek Group. “Not only can the UROS centralizer fully compress within the sub body, but the Centek sub has the ability to rotate when fully compressed in the tightest of restrictions with no loss of eccentricity at the end-bands.”
The size range is expected to be 7.3/4in through to 18in or as required, and the sub body can be threaded to meet the customer’s requirements for the casing string.