Drilling stabilizer

A drilling stabilizer is a piece of downhole equipment used in the bottom hole assembly (BHA) of a drill string. It mechanically stabilizes the BHA in the borehole in order to avoid unintentional sidetracking, vibrations, and ensure the quality of the hole being drilled.

It is composed of a hollow cylindrical body and stabilizing blades, both made of high-strength steel. The blades can be either straight or spiralled, and are hardfaced for wear resistance.

Several types of drilling stabilizers are used in the oilfield today. While integral stabilizers (fully machined out of a single piece of steel) tend to be the norm, other types can be used, such as :

Usually 2 to 3 stabilizers are fitted into the BHA, including one just above the drill bit (near-bit stabilizer) and one or two among the drill collars (string stabilizers).

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