Abstract: A method of attenuating annular pressure buildup within a wellbore. The method includes running first and second strings of casing into a wellbore, wherein the first string of casing surrounds an upper portion of the second string of casing forming an annular region. The method also includes providing a packing of compressible material within the annular region. The compressible material comprises carbonaceous particles. The particles may reside within a porous sleeve or filter, or they may be packed together in a matrix using a cross-linked polymer or binder. The packing is fixed at a selected depth within the annular region, and is designed so that the compressible material absorbs pressure in response to thermal expansion of wellbore fluids during the production of hydrocarbon fluids from the wellbore. The method further includes placing a wellhead over the wellbore, thereby forming a trapped annulus in the wellbore over the annular region.

Abstract: A viscous fan drive for an engine cooling system has an output coupling defining a fluid operating chamber, an input coupling disposed in the fluid operating chamber, and a driveshaft coupled to the input coupling and defining a driveshaft axis. A main bearing has an inner race coupled to the driveshaft and an outer race coupled to the output coupling, the main bearing defining a bearing axis, wherein the bearing axis is normally substantially coincident with the driveshaft axis. A brace is disposed between the outer race of the main bearing and the output coupling. The engine cooling system may be provided on a machine having a rotatable frame that promotes precession of the output coupling, wherein the brace prevents movement of the main bearing along the driveshaft in response to the output coupling precession.

Abstract: A compact multistage planetary final drive mechanism includes a housing structure and associated wheel rotatably mounted on a hollow spindle, and a planetary gear apparatus for driving the housing structure at a relatively high speed reduction ratio in response to rotation of an input shaft. The planetary gear apparatus includes a first stage cluster gear set operatively connected to a second stage planetary gear set. A plurality of planet gears of the planetary gear set are rotatably mounted on the spindle, a parking brake mechanism is mounted within the spindle, and a first trough is defined annularly about the spindle. A second trough is defined within the housing structure, first and second pairs of wire raceways are seated within the respective troughs, and a plurality of roller bearing elements are cross connected within the wire raceways to transmit thrust and radial loads from the wheel to the spindle.