Multi phase metering with low field NMR. Abstract 98

'Full text:' In conventional oil productions, commonly there is a simultaneous production of oil, water and gas. Furthermore, thermal recovery methods are widely used in heavy oil production. Under steam injection, the viscosity of oil will be significantly decreased and will be produced. With oil production, gas, steam and water will be produced simultaneously. The question of how to accurately meter oil, water and steam or gas content accurately comes up. Solving this problem and precisely measuring oil production rate in conventional and heavy oil operations is becoming an increasingly important issue. The goal of this study is to build a three-phase water cut meter laboratory device using low field NMR. If successful it will then be applied in oil field trials. Preliminary results of laboratory testing at ambient temperature obtained to date are presented here. Three types of oil, light, conventional heavy and bitumen, with corresponding viscosities around 10 cp, 1,500 cp and 700,00 cp respectively, were used to perform screening experiments with a flow through NMR that was designed for two-phase water cut measurements. 2% NaCI brine was used as the water phase. Air was used as the gas phase. The fluids were mixed in a fixed volume vial. The weight percentage of oil was from 5% to 95% respectively. At each oil percentage, the weight percentage of water was 5% to 95% respectively. The void space of the testing vials was used as the gas phase. In order to calculate the fluid content, the amplitudes obtained from mixtures oil and water was compared with the values of pure oil and water. The water and oil contend calculated from NMR results and were compared to those from mass balance. The results indicate that the water content value obtained from mixture for light and conventional heavy oil is excellent when compared to mass balance. For bitumen the results were very good, but not as good as the results of conventional oil. Improvements in the measurement procedures implemented specifically for bitumen show promise that the measurement quality for bitumen will reach that of conventional oil and gas. (author)