Provided are systems and methods for forming a casing liner in a wellbore of a hydrocarbon well. The forming including disposing a casing liner print head in an annular region located between a casing pipe disposed in a wellbore of a hydrocarbon well and a wall of the wellbore, and conducting a downhole lining operation including operating the casing liner print head to eject casing liner material into the annular region to form, in the annular region, a casing liner including elongated voids formed in the casing liner material.