Abstract: A wellbore cleaning device having a unitary tool mandrel surrounded by a retaining sleeve that is rotatable with respect to the mandrel. A locking ring is used to secure the retaining sleeve to the mandrel. Cleaning blades are retained within recesses in the retaining sleeve and are biased radially outwardly from the recesses by springs.

Abstract: A wellbore cleaning device having a unitary tool mandrel surrounded by a retaining sleeve that is rotatable with respect to the mandrel. A locking ring is used to secure the retaining sleeve to the mandrel. Cleaning blades are retained within recesses in the retaining sleeve and are biased radially outwardly from the recesses by springs.

Abstract: A circulating sub is run in with the circulating port closed. A dart blocks a central passage and moves two concentric pistons in tandem to open the circulation port while retaining the dart. The outer piston shoulders out in the circulation port open position. A second dart lands on the first and with applied pressure moves the inner piston relative to the shouldered outer piston to close the circulation port and only then discharge both darts. Subs can be used in tandem as long as higher located subs accept larger darts than lower subs and preferably the two darts for each sub are the same size. The ejected darts can be used to pressure actuate a downhole tool like a packer.

Abstract: Non-rotating tubular wellbore cleaning devices are described which include a central tool mandrel with radially surrounding stabilizers and a cleaning member subassembly. A rotational bearing is provided that is partially radially recessed, thereby improving the overall strength of the cleaning device.

Abstract: A circulating sub is run in with the circulating port closed. A dart blocks a central passage and moves two concentric pistons in tandem to open the circulation port while retaining the dart. The outer piston shoulders out in the circulation port open position. A second dart lands on the first and with applied pressure moves the inner piston relative to the shouldered outer piston to close the circulation port and only then discharge both darts. Subs can be used in tandem as long as higher located subs accept larger darts than lower subs and preferably the two darts for each sub are the same size. The ejected darts can be used to pressure actuate a downhole tool like a packer.