Patent ID: 6158534
Filing Date: 2000-12-12
Classification: E21B

Abstract:
Core sampler, particularly for oil prospecting, comprising:coring bit (2),an outer barrel (3) for rotating the coring bit (2), andan inner barrel (5) for receiving a core sample (7) in an interior space (8) during core sampling, the inner barrel (5) and outer barrel (3) being substantially coaxial, characterized in that the core sampler additionally comprises:a middle barrel (15) arranged coaxially between the inner barrel (5) and the outer barrel (3) delimiting, on the one hand with the outer barrel (3), a first longitudinal channel (16) for core sampling fluid and, on the other hand, with the inner barrel (5), a second longitudinal channel (17) for core sampling fluid, the longitudinal channels (16, 17) and the interior space (8) each having a front end (16A, 17A, 8A) close to the coring bit (2) and a rear end (16B, 17B, 8B) remote from this bit (2),a valve (18) which can be selectively opened or closed, and which at least temporarily, provides, when open, or blocks, when closed, coring fluid communication between the rear end (17B) of the second longitudinal channel (17) and/or that (16B) of the first longitudinal channel (16) and/or that (8B) of the interior space (8) whereby when the valve is open, core sampling fluid may flow through the valve from the rear end (8B) toward the front end (8A) of the interior space (8), andwhereby core sampling fluid displaced from the interior space (8) when the valve (18) is closed flows from the second channel (17) to the front end (8A) of the interior space before flowing away from the bit (2).