A core sample holder assembly for performing laboratory core flooding experiments with a core sample: a pressure chamber provided by a tubular hull made of a carbon fiber composite material and an aluminum liner, and a pair of disk-shaped flanges; a flexible core sample holder sleeve within the pressure chamber, which sleeve comprises a tubular steel sheet with a plastic inner lining; an opening for injecting oil into an annular space between the hull and the sleeve; pressure control means for maintaining the oil at a predetermined pressure; an fluid injection port for injecting a fluid into a cylindrical core sample within the sleeve; a fluid outlet port arranged in the other flange for discharge of fluid from the core sample; and means for monitoring the migration of injected and/or pore fluid through the pores of the core sample.