Abstract: There is disclosed an apparatus for pumping multiphase fluids in oil field production, particularly a twin-screw pump for providing a large pressure boost to high gas-fraction inlet streams. The pump includes a housing having an internal rotor enclosure, the enclosure having an inlet and an outlet and a plurality of rotors operably contained in the enclosure. Each rotor has a shaft and a plurality of outwardly extending threads affixed thereon, the rotors being shaped to provide a non-uniform volumetric delivery rate along the length of each rotor. The pump also has means for rotating the rotors, whereby a fluid stream entering from the inlet is subjected to a pumping action to transport the fluid stream to exit the rotor enclosure through the outlet. In one embodiment, the rotors have a plurality of threaded pumping stages separated by unthreaded non-pumping chambers.

Abstract: A liquid anticorrosion composition adapted for application to ferrous tubular goods is provided comprising an aqueous solution of cyclohexylammonium benzoate and a benzoate salt, which is preferably prepared by reacting cyclohexylamine with excess sodium benzoate in an aqueous alcohol solvent. A sealable thread protector end cap which protects the precisely machined threads from physical abuse and which isolates or seals from the environment the corrosion inhibitor composition is also provided.