A densitometer is used for quantitative density determinations of fluids being produced from core samples during flooding experiments at reservoir conditions. The densitometer is situated in the flowline immediately after the core holder, and measures the density of all fluids being produced from the core sample at the actual pressure/ temperature (P/T) conditions of the flooding experiment. In addition, the densitometer provides timing information about dynamic events during the experiment, e.g. water breakthrough or gas breakthrough.
In the case of two-phase experiments, the densitometer may be used for determining the volumes of the two produced phases, if the density of each of the two fluid phases is known; this is the case in many flooding experiments using oil and water. In such cases, the densitometer may provide data for the produced volumes of oil and water that agree reasonably with fluid volumes determined by an acoustic separator. In complex and prolonged flooding experiments, the densitometer volume determinations may provide an independent confirmation of the volume determinations of an acoustic separator or possibly other devices.
During coreflooding experiments at reservoir conditions it is important to keep track of the fluids being produced from the core sample. For this purpose, a densitometer situated in the flowline immediately downstream to the core sample has proved useful. The densitometer (Paar DMA HPM) has been used at GEUS for obtaining precise density measurements of the fluids being produced from core samples at temperatures up to 115°C and fluid pressures up to 420 bar (Olsen, 2011). However, the rating of the device allows use up to 200°C and 1,400 bar.