System for monitoring injection water quality using filtration, pressure regulation and mass measuring

摘要

An apparatus for testing water quality for subsurface injection that provides for samples of infinite volume to be passed over a membrane filter at a constant pressure. The apparatus uses a positive displacement pump drawing suction on the water source and discharging to a membrane filter. Between the pump discharge and the filter is an oil/water separation vessel to allow for sampling of well production fluids before oil removal if necessary. Fitted to the oil separation vessel is an adjustable pressure regulator, also known as a back pressure regulator, for maintaining constant pressure over the filter. The filter discharge water is collected in a volume calibrated vessel. The vessel is connected to load cells, and a data collection device records weight as a function of time. By measuring the water density, a time/volume curve can be automatically plotted by the data collection device. This apparatus would find application in performing a variety of field tests, however, testing of water quality for injection wells is the most likely application for the apparatus.