| Popis: |
Horizontal well production logging (PL) measurements, especially center-sample devices, have been misleading in evaluation of the flowing stream. These inaccuracies are due to the natural segregation of the fluids owing to the difference in the phase densities. A new multiphase holdup tool and interpretation method has been developed that provides accurate determination of holdups and flowrates in horizontal wells. The multiphase holdup tool uses 12 capacitance-sensing circuits with multiple arm arrangements to provide an excellent image of the holdup pattern. Since these sensors are on the same cross-sectional plane, depth inconsistencies are not a factor in the interpretation. Each sensor responds to the permittivity (dielectric constant) of the surrounding fluids, and the response can be converted to a phase holdup by applying the known sensor calibration. Consideration of each sensor's position relative to the wellbore allows for prediction of the total phase holdup across the entire wellbore cross sectional plane. Advanced analysis packages allow the user to interact with the computed holdups, providing an easy method of interpretation. Different views of the wellbore, cross-sectional displays, and displays incorporating the wellbore trajectory allow accurate and detailed analysis that is critical for understanding flow in horizontal wells. Once the holdup of each phase (gas, oil, and water) is determined, an additional interpretation package allows a complete production log analysis including flowrates in a very difficult environment. The results of these analysis packages allow an operator to understand, modify, and improve the productivity of a horizontal well. |
