Abstract: The present invention relates generally to drilling and well servicing operations, particularly to additives comprising polystyrene to control lost circulation; drilling fluids comprising the additives; and methods of using same.

Abstract: An apparatus for wellbore treatment includes a tubular with one or more solid, erodible blocks on its outer surface. The blocks carry a chemical for wellbore treatment that is released in the wellbore by erosion of the blocks against the wellbore wall. A method for wellbore treatment employs the tubular to release the chemical in the well by erosion of the blocks.

Abstract: Lost circulation of drilling fluid is one of the most serious and expensive problems facing the drilling industry. The present invention relates to an improved drilling fluid for reducing or preventing lost circulation to an underground formation surrounding a well bore in the process of drilling a well. The drilling fluid comprises a base fluid and wax or waxy substance as a primary seepage loss agent. The invention also provides a method of reducing or preventing lost circulation to an underground formation surrounding a well bore in the process of drilling a well using the drilling fluid of the invention, wherein the primary seepage loss agent is added to the drilling fluid, either before or during drilling, and the drilling fluid is pumped down hole during drilling.

Abstract: A boat accessory rack has a frame typically including at least two members, one of which is movable. An actuation device such as a manually operated actuator, a hydraulically operated actuator or a pneumatically operated actuator applies an actuation force to the movable member thereby moving the movable member from an unclosed position into a closed position in which the wakeboard is secured. A releasable locking mechanism such as a ratcheting mechanism, an interlocking ring mechanism, a ball bearing system or an over-centering system maintains the movable member in the closed position until a user desires to remove the wakeboard from the rack. Also, a cam mechanism transfers the actuation force to the movable member in some embodiments. In other embodiments, the accessory is secured between a rotating wedge mechanism and a second member.