ROTATING CELL TEST APPARATUS FOR CORROSION STUDIES IN MULTIPHASE FLOW INVOLVING GAS, WATER, OIL, AND SAND

摘要

A test apparatus was developed to study CO_2 corrosion and simulate flow conditions in a multiphase pipeline involving gas, water, oil, and sand. The apparatus consists of a grooved rotator concentric with a vertical glass cylinder on which four steel cylindrical electrical resistance bands are located: one on the cell bottom and three on the inner wall at different elevations. The resistance bands and computer controlled electronics enable a corrosion measurement sensitivity of 1 mpy with a 24 hour of exposure period, 2 mpy in 12 hours, 0.5 mpy in 48 hours, etc. Spinning the rotator generates turbulent fluid flow against the inside of the outer vessel walls where the resistance bands are located. At low speeds, the phases include moving sand bed, water phase, oil phase and gas phase; and with proper band location monitoring of corrosion rates in each of the separate phases can be performed. At higher speeds a single multi-phase emulsion and a gas phase occur with the capability of generating shear stresses up to 75 Pa. Test results involving inhibitor evaluations are also presented.