Non-metallic oil pipelines; Casings, not of metal for oil wells; Barriers of non-metallic materials use in the oil and gas industry; Refractory products in the form of non-metal linings; Non-metallic linings for use in construction; Non-metallic rigid pipes; Ceramic articles for construction purposes, namely, an annulus insert for construction of oil and gas wellheads; Ceramic refractory work pieces, namely, ceramic refractory liners for insertion into an oil and gas wellhead