FORMATION-SAMPLING APPARATUS

摘要

In the representative embodiment of the new and improved fluid-sampling apparatus disclosed herein, sample-admitting means adapted to be selectively extended therefrom include an annular sealing pad operatively arranged around the forward end of a tubular sampling member so that, upon contacting a well bore surface, the pad will make firm sealing engagement therewith. First new and improved means are provided for delaying the establishment of flow communication between a sample-collecting system in the apparatus and an earth formation being tested until the sample-admitting means have been extended and mudcake and formation materials that might otherwise plug the sampling apparatus have been removed from the forward portion of the sampling member. Second means are uniquely arranged for limiting the admission of formation materials into the sampling member so that the sealing engagement of the sealing pad will not be disrupted by the entrance of additional formation materials into the sampling member. As a result of this new and improved apparatus, fluid samples can be obtained at high flow rates.