Centralizer cementing tools, it makes simple, and beautiful structure, durable, strong centering force, prone to overcome the original welded lifter desoldering , is a kind of centralizer can ensure quality of drilling cementing. The sort is various, according to the structure can be divided into the roller type, the sliding block type, automatic reversing type, etc. Different structure and material of centralizer, applies to different types of eccentric wear oil well. On the part of eccentric wear prevention, the most critical is installation location, spacing, and number.