| Popis: |
Well testing is one of the most effective means to characterize hydrocarbon reservoirs under dynamic conditions. Such characterization of reservoirs is as accurate as the data used for interpretation. It is, therefore, essential to have accurate measurements of both rates and pressures due to their complementary nature. Although pressure measurements are accurate, one needs to pay more attention to the rate measurements, especially during the early stages of exploration. Accurate measurements of gas and liquid flow rates using a separator are very difficult because of poor separation among the three phases when the flowing oil is heavy and viscous. This condition gets even worse in situations like low gas rates, low density contrasts among liquids, contamination of the different effluents after separation, and well instabilities leading to carry-over or carry-under. Multiphase metering based on a dual-energy Venturi technology enables simultaneous, accurate rate measurements of oil, water and gas phases produced from development, exploration or appraisal wells, while the downhole gauges measure the pressures. This paper presents comprehensive results from field tests conducted with multiphase meters in carbonate reservoirs producing Arabian heavy oil. These tests were conducted with production logging tools enabling characterization of laminated layers. Complete analyses of downhole gauge data are presented to demonstrate how the characterization of investigated formations improves with accurate rate measurements. It is also shown that if the rate measurements are not rigorous, it might lead to a misleading interpretation of the acquired pressure data. |
