Application of Innovative Ceramic Centralizer for Solid Expandable Liner

Abstract

Traditionally, solid expandable liners have been run without any centralizers due to the perceived risk involved, since typical centralizers would impose extra restrictions on the pipe body, which would require additional force to expand. Also, the centralizers may break during running in hole, which would lead to a possible stuck liner, and consequently, be a major problem of liner expansion. It's also important to realize that there is a limited running clearance if conventional centralizers are utilized. This puts a lot of constraints on the type and availability of possible centralizers. As a result, some residual mud may remain on the low side of the hole during cementing operations, since it is not possible to rotate the expandable liner while cementing, nor reciprocate the liner after reaching setting depth to avoid possible damage of the expandable casing's connection protection sleeves across the prevous 7 in. casing shoe or window exit. Consequently, the cement bond between the expanded casing and the formation would be limited and long-term isolation may be less than required.Recently, an innovative ceramic centralizer was evaluated and implemented in the field. The ceramic centralizer consists of three individual pads affixed to the expandable casing 120 degrees offset to each other, with three centralizers equally spaced out along the middle part of the 38 ft expandable casing joint. The pad itself is made of carbon fiber ceramic composite material that is characterized by strong toughness. Once bonded to the base pipe it is not possible to remove it even with 180,000 lbs of force. It has a lower friction factor than casing, and is corrosion resistant. After tailoring the pad design to suit a 5½ in. expandable liner, such centralizers on cemented expandable liners were successfully run in five wells without any problem. The acquired ultrasonic image tool (USIT) log demonstrated that the cement bond with such centralizers was substantially better than the case without the use of any centralization.

Applied Technologies for Successful Cementing in Steam Injection Wells in Southern Mexico

“…Zhou et al (2010) provides a full explanation of the process to attach the centralizer to the casing. They are a field-proven, cost-effective alternative to conventional centralizers because of their composition and customized shape, which can help minimize friction when running in casing, improve flow area, and provide better standoff for highly deviated or horizontal wells.…”