Rotating bow-spring centralizers

10 June 2011 Dear Professionals,

Cementing 7" liners in 8 1/2" hole size using 7 3/4" Spyrogliders has resulted in poor zonal isolation and inadequate cement bond, as expected. Rotating liners at 15 RPM, increasing to 20 and 30 RPM on the following wells did not help improve the situation. A proposal is thus made to use bow spring centralizers with intention to rotate. The stocks we have are typical Weatherford's STA-2 and STA-3, which we are looking to replace with some more robust integral Centek bow spring centralizers. I consider them being a step between simple non-weld or weld-on bow springs and sturdy and heavy duty centralizer subs.

In my previous experience, we did rotate liners with centralizers subs with great results in the end. Additionally, we rotated liners with a mixture of bow-spring cents and spiro-glyders at low RPMs.

My question to the community is whether anyone has experience in rotating:

a) liners with heavy set bow spring centralization at high RPMs (e.g. 20-30 RPM)

b) experience rotating liners with Centek centralizers vs doing the same with STA types...

Thanks a lot,
Rufat Mammadbayli
BP

12 Answer(s)

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