|
Reversal of water coning in wels with downhole water sink completion - experimental analysis |
|
|
|
|
Reversal of water coning in wels with downhole water sink completion - experimental analysis Authors: E. i. Shirman, A. K. Wojtanowicz
Feasibility of water coning reversal in dual-completed oil wells is demonstrated and analyzed using a Hele-Shaw bench-top physical model. The model simulates the process of well production from a linear oil reservoir with strong bottom water drive. The well's installation represents an innovative well completion method with downhole water sink (DWS). In this technique, a well is dual-completed in oil and water columns with a packer separating the two completions. The two completions enable effective contral of water coning by draining the water from the bottom (water sink) completion below the oil water contact (OWC) while producing an oil-rich stream of fuids from the top completion. Video-recorded experiments with the see-through Hele-Shaw physical model visually demonstrate the process of water cone development, reversal, and the creation of an inversed oil cone. Also, numerical data collected from the experiments show the effects of DWS design parameters on the reversal process performance. A theoretical analysis is also presented to show if the results from the linear physical model apply to the actual wells. Flow in the Helle-Shaw model was described mathematically using the recently-published method of Moving Spherical Sink (MSS). The analysis defines approximate rules for inferring radial flow principles from the linear flow results. The results demonstrate how productivity of a "watered out" well could be recovered resulting in significant production of oil. Also, the oil produced from the top completion could be water-free. The study reveals that under conditions of severe water coning, unlike conventional wells, a significant production of oil from wells with DWS completions is technically feasble due efficient coning reversal.
|
2011