Disclosed is a short fiber-reinforced rubber wherein a fibrilated polyacrylonitrile short fiber is uniformly dispersed in a rubber, and a process for producing the same.
An endless power transmission belt having (1) a tension section; (2) a cushion section; and (3) a load-carrying section disposed between said tension section and cushion section; and the belt containing an elastomeric composition comprising (a) cross-linked elastomer; and (b) from 1 to 50 phr of high molecular weight polyacrylonitrile fiber.
A nitrite polymer vulcanizate having improved hot air aging characteristics is described. The nitrite polymer vulcanizate may be produced admixing a composition comprising: (i) a nitrite polymer; (ii) a filler; (iii) an additive selected from the group comprising: a strong base, a salt of a strong base and a weak acid, a salt of a weak acid, a carbodiimide, a polycarbodiimide and mixtures thereof; and (iv) a vulcanization system. A vulcanizable composition useful for producing such a vulcanizate and a method for improving the hot air aging characteristics of a nitrite polymer are also described.
A stripper rubber for oil and gas wells, water and geo-thermal wells, having an interior surface design which includes a circular, convex knee portion in the throat area of the stripper rubber to provide additional support to the stripper rubber during insertion of a tubular member through the stripper rubber. The composition for the stripper rubber includes, in one embodiment, enhanced wear characteristics by the addition of milled fibers of Twaron.RTM. mixed homogeneously throughout the stripper rubber.
An apparatus for controlling a subsea borehole fluid pressure is proposed for use with a conductor casing positioned below the mudline and within a normal pore pressure environment. The apparatus includes a pump for moving a fluid through a tubular into a borehole. The fluid, before being pumped, exerts a pressure less than the pore pressure of an abnormal pore pressure environment. The fluid in the borehole is then pressurized by the pump to at least a borehole pressure equal to or greater than the pore pressure of an abnormal pore pressure environment. A pressure housing assembly allows for the drilling of a borehole below the conductor casing into an abnormal pore pressure environment while maintaining the pressurized fluid between a borehole pressure equal to or greater than the pore pressure of the abnormal pore pressure environment, and below the fracture pressure of the borehole in the abnormal pore pressure environment. Advantageously, a method is provided for drilling a borehole into the subsea abnormal pore pressure environment.