Top-Co's centralizers and casing accessories are designed and manufactured to assist casing running and cementing. Starting, Running and Restoring force tests performed in Top-Co's Test Facility as per API Specification 10D, and holding force tests as per API Recommended Practice 10D-2. The tests are conducted at Top-Co's state-of-the-art testing facility, which features a fully computerized centralizer test bench.
Preferred installation is over the stop collar. This allows for the bow spring centralizer to be pulled into the hole during run-in (Fig 1). Pushing the centralizer will increase starting and running forces and may damage the bows.
Placement over the coupling eliminates need for stop collar but can reduce standoff at midspan (Fig 2).
For solid body centralizers, stop collars are recommended to be placed above and below centralizer (Fig 3), but can also be installed between collar and coupling (Fig 4), or they are installed to float between couplings.