Probe and sample holder for magnetic resonance and magnetic resonance imaging

A core holder for containing a reservoir rock core sample for MR or MRI measurement comprising:

• a casing having sufficient tensile strength to withstand being pressurized to an underground formation pressure, comprising
• a cylindrical wall and end closures for closing the ends of the casing wherein
• at least one of the end closures is removable to provide access to the inside of the casing, the wall and end closures defining a chamber internal to the core holder,
• an inlet and an outlet in the core holder for circulating a confining fluid in the chamber,
• a sample housing in the chamber for containing the core sample, the sample housing comprising
• an inlet and an outlet in the sample holder for circulating fluid to and from the sample, and
• a membrane for isolating the sample from fluid contact with the confining fluid but permitting fluid pressure to be exerted on the sample when the confining fluid is pressurized,
• the space in the chamber not occupied by the sample housing defining a void space,
• a radio frequency probe, connectable to an NMR or MRI apparatus, in the void space and at least partially surrounding the sample housing, whereby confining fluid introduced into the chamber circulates in the void space around the RF probe.