US Patent 11933113 Expandable drill pipe centralizer/stabilizer

The centralizer also includes a body defining a central bore and a plurality of cavities fluidically coupled to the central bore and an exterior of the body, where the plurality of cavities are located between the central bore and an outer surface of the body. The centralizer also includes a plurality of springs with each housed in one of the plurality of cavities. The centralizer also includes a plurality of pistons with each housed in one of the plurality of cavities and abutting a respective spring in that cavity. The centralizer also includes a centralizer pad pivotally connected to each of the plurality of pistons and extending radially from a longitudinal axis of the body in response to bias from the plurality of springs.