Abstract: Head pressure and extruder torque in the extrustion of linear ethylene polymers such as linear low density polyethylene (LLDPE) are reduced by adding a small amount (less than 5 weight percent) of a thermoplastic polyurethane. Films extruded from the blend exhibit better surface appearance by reduction of melt fracture.

Abstract: A gel-forming composition capable of plugging highly permeable zones in a subterranean formation. The composition comprises water, a viscosifying amount of a water-dispersible polyvinyl amine copolymer and a crosslinking agent which is a mixture of an aldehyde and a phenolic component in an amount effective to cause gelation of the aqueous solution of the copolymer. The resultant gel is exceptionally thermally stable and, therefore, can be used as an effective profile control agent in all enhanced oil recovery operations, including steam flooding.

Abstract: An anti-sand bridge tool for dislodging a sand bridge between a liner wall and a casing wall of a gravel packed well completion. The tool comprises a tubular sub pipe having a first end and a second end, the first end having means for connecting the tubular sub pipe to a tubular work string; a hollow flexible member for delivering a fluid at high pressure having a first end and a second end, the first end of the flexible member adapted for attachment to the second end of the tubular sub pipe; and a striking means having a fluid inlet orifice and at least one fluid exit orifice, the fluid inlet orifice connected to and in fluid communication with the second end of the flexible member; whereby initiation of fluid flow through the tool effects an arcuate movement of the striking means resulting in the striking means contacting the liner wall in a manner effective to dislodge a sand bridge. Also provided is a method for dislodging sand bridges encountered during gravel packing operations.

Abstract: A semi-continuous, multi-stage polymerization process is provided for synthesizing a heat-sealable multi-layered composite particle latex. The multi-layered composite latex particles of this invention provide excellent oxygen and vapor barrier properties without hindering the desired surface properties, including high heat-sealing strength, low minimal seal temperature, excellent machinability, i.e. low blocking and low coefficient of friction. The latex particles of the present invention are formed as three-layered composite particles having an acrylic ester seed layer composed of a copolymer of methyl methacrylate and methyl acrylate. The latex particles have an intermediate core layer composed of a terpolymer having a high vinylidene chloride concentration, the other comonomers of the core layer include methyl acrylate and methacrylic acid.

Abstract: A process for use with a polymer which is crosslinkable by reaction with an amino resin, which comprises the steps of determining a period of time within which full gelation of the polymer is to be achieved; preparing a gel-forming aqueous-based mixture comprising the polymer, a rapid amino resin crosslinking agent and a delayed amino resin crosslinking agent, the gel-forming aqueous-based mixture capable of complete gelation within the period of time so determined; partially gelling the aqueous-based mixture by reacting the polymer with the rapid amino resin crosslinking agent which is effective to complete the partial gelation by crosslinking the polymer within four hours; and fully gelling the aqueous-based mixture by reacting the polymer with the delayed amino resin crosslinking agent which is effective to complete the full gelation by crosslinking the polymer within the period of time so determined. A method of enhancing the recovery of oil from a subterraean oil-bearing formation is also provided.