Abstract: Wellhead distribution valving (known in the trade as a Xmas tree) are protected from potential thieves by security apparatus that prevents access to the mounting flange bolts of the wellhead valving. This security apparatus comprises a housing having two similar half sections. Each half section includes an outer wall, a semi-annular top and a semi-annular bottom. A plurality of locking members are integrally attached to the outer wall at each half to mate with a locking receptacle attached to the inner surface of the outer wall of the mating half section. An inner core of a metallic material is incorporated into the outer wall, the top and the bottom to increase the difficulty of penetration through the surface housing.