Downhole debris-collecting tool having an improved valve

Abstract

The downhole tool comprises: (i) a housing connected with a collection chamber for receiving debris, the housing having an opening for collecting the debris from the petroleum well, the opening in fluid communication with the collection chamber through the housing; (ii) a rotatable shaft with transport blades arranged within the housing and extending from the opening to the collection chamber, the rotatable shaft configured for transporting debris from the opening to the collection chamber in operational use; (iii) an annular area defined between the rotatable shaft and an inner wall of the housing and (iv) a valve configured for keeping debris in the collection chamber. The valve is located within the housing between the opening and the collection chamber. The valve comprises a seal member with a movable part mounted in the annular area and around the rotatable shaft. The valve is opened when the movable part moves in direction of the collection chamber and is configured such that the movable part of the seal member is only movable in the direction towards the collection chamber when closed. The downhole tool provides a valve, which is easily opened, requiring a very small force, while providing a very good sealing effect when the seal member is closed.