Abstract: This invention relates to well cleaning methods and apparatus. In particular, this invention relates to a method of drilling and cleaning a wellbore. In one embodiment of the invention, a method of drilling and cleaning a wellbore (12) is disclosed. The method comprises the steps of providing a drill string (10) having a drill bit (28) and a cleaning tool (24) with selectively activatable cleaning members (34); drilling a wellbore using the drill bit while maintaining the cleaning members in a deactivated position; and pulling the drill string from the wellbore with the cleaning members in an activated position, to thereby clean the wellbore. A corresponding cleaning tool is also disclosed.

Abstract: A clamp (10) for holding two members together. The first member includes a recess into which a fastener is located. A bore is provided to the recess to allow a tool to be used to operate the fastener. The second member is arranged to accept the fastener and so join the members. The recess and bore are sized to prevent release of the fastener through the bore. In this way, the fastener cannot easily be removed or lost when the clamp is in use and is tamperproof. Embodiments of a downhole tool are described where the clamp is used to hold portions of a sleeve around a body of the tool, and to hold scraper blades and/or brushes to the body.