Abstract: A selectively operable downhole valve for use with core sampling apparatus, the valve comprising a throughbore through which a first body may pass, and an obstructing member which is capable of selectively obturating the throughbore, the obstructing member being arranged to open or close the throughbore by movement of the first body with respect to the valve. A core sample of the formation may then be obtained and retrieved from the bore under pressure since the valve seals the bore downhole. Retrieving the sample under pressure maintains the integrity of the core sample so that subsequent analysis of the sample will more closely reflect the true characteristics of the formation.

Abstract: A method and apparatus for handling a geological sample, such as a core from a formation. The formation may be a formation of an oil and/or gas well. The apparatus includes a container for receiving the sample and is characterized in that the container comprises at least one wall with a surface which can change its configuration in response to pressure changes. The method of handling a geological sample obtained includes providing a container for receiving the sample. The container has a surface which is capable of changing its configuration in response to pressure changes. The sample is introduced into the container, and the configuration of the surface is changed to contact the sample. The container is then withdrawn from the formation.