Dual-completed wells with Downhole Water Sink (DWS) are used for water coning control in oil reservoirs with bottom water drive. In DWS wells, the second (bottom) completion—placed in the water column—is used for draining water. This prevents the water cone invasion and allows free oil inflow in the top completion. The decision on using DWS or a conventional (single-completed) well is based upon deliverability comparison of the two wells. This paper shows how to describe DWS well deliverability in terms of the top and bottom production rates, water cut, and pressure drawdown. Also, the effect of pressure interference between two well completions on deliverability limits has been studied and qualified experimentally. DWS well deliverability depends on two variables, pressure drawdown and water drainage rate, and is described by a three-dimensional Inflow Performance Domain (IPD). Visual-Basic software based on a new analytical model of IPD has been developed to calculate critical (fluid breakthrough) rates for oil and water. The critical rates identify inflow conditions to the well’s completions—single or two-phase inflow. Also calculated are the values of water cut and maximum pressure drawdown at the well. An example demonstrates the procedure and a complete IPD plot. The experimental study, using a Hele-Shaw physical model of DWS well, demonstrates the reduction of well’s deliverability caused by pressure interference from the second (bottom) completion. The experiments have shown, however, that the deliverability decrease is small and over-compensated by the increase of oil rate due to simultaneous reduction of water cut.

Issue Section:
Technical Papers
Keywords:
oil technology, water, hydraulic systems, pressure control, computer software, two-phase flow
Topics:
Pressure, Water, Drainage, Inflow, Wells, Fluids
1.
Loginov, A., and Shaw, C., 1998, “Completion Design for Downhole Water and oil Separation and Invert Coning,” SPE 38829, Proc. 72nd Annual Technical Conference and Exhibition of SPE, San Antonio, Texas, October 5–8, 1997, also, Journal of Petroleum Technology, March 1998, pp. 70–73.
2.
Chea, C. K., et al., 1998, “In-Situ Gravity Segregation Eliminates Bottom Water Coning,” Proc. 26th Convention of Indonesian Petroleum Association, May, 1998.
3.
Bowlin, K. R., et al., 1997, “Field Application of In-Situ Gravity Segregation to Remediate Prior Water Coning,” SPE 38296, Proc. 1997 SPE Western Regional Meeting, Long Beach, CA June 25–27, 1997, also, Journal of Petroleum Technology, October 1997, pp. 1117–1120.
4.
Chruseh, L. I., 1996, “Downhole Oil and Water Separation–Potential of a New Technology,” IPA 96-2.4-156, Proc. Indonesian Petroleum Association 25th Silver Anniversary Convention, Jakarta, October 1996.
5.
Shirman, E. I., and Wojtanowicz, A. K., 1997, “Water Coning Reversal Using Downhole Water Sink—Theory and Experimental Study,” SPE 38792, Proc. 72nd Annual Technical Conference and Exhibition, San Antonio, TX, Oct. 5–8, 1997.
6.
Shirman, E. I., and Wojtanowicz, A. K., 2000, “Maximum Deliverability of Dual-Completed Wells with Downhole Water Sink (DWS)—Analytical and Experimental Study,” Proc. ETCE/OMAE 2000 Conference, New Orleans, LA, Feb. 14–17, 2000.
7.
Shirman, E. I., 1996, “A Well Completion Design Model for Water-Free Production from Reservoirs Overlaying Aquifers,” SPE International Student Paper Contest, Proc. Annual Technical Conference and Exhibition, Denver CO, Oct. 6–9 1996, Vol. II, 853–860.
8.
Shirman, E. I., 1998, “Experimental and Theoretical Study of Dynamic Water Control in Oil Wells,” PhD dissertation, Louisiana State University, Baton Rouge, LA.
9.
Shirman, E. I., 1995, “An Analytical Model of 3-D Flow Near a Limited-Entry Wellbore in Multilayered Anisotropic Strata—Theory and Application,” MS thesis, Louisiana State University, Baton Rouge, LA.
10.
Wojtanowicz
,
A. K.
, and
Shirman
,
E. I.
,
2000
, “
More Oil Using Downhole Water Sink Technology: A Feasibility Study
,”
SPE Prod. Facil.
,
15
(
4
), pp.
234
–
240
.
11.
Inikori, S. O., and Wojtanowicz, A. K., 2001, “Assessment and Inclusion of Capillary Pressure/Relative Permeability Histeresis Effects in Downhole Water Sink (DWS) Well Technology for Water Coning Control,” ETCE2001-17100, Proc. Engineering Technology Conference on Energy, Houston, TX.
12.
Inikori, S. O., and Wojtanowicz, A. K., 2001, “Contaminated Water Production in Old Oilfields with Downhole Water Separation: Effects of Capillary Pressure and Relative Permeability Histeresis,” SPE 66536, Proc. SPE/EPA/DOE E&P Environmental Conference, San Antonio, TX, Feb. 26–28.
13.
Inikori, S. O., 2002, “Numerical Study of Water Coning Control with Downhole Water Sink (DWS) Completions in Vertical and Horizontal Wells,” PhD dissertation, Louisiana State University, Baton Rouge, LA.
14.
Muskat, M., Physical Principles of Oil Production, McGraw-Hill Book Company, Inc, New York, Toronto, London, 1949, pp. 226–229.
15.
Johns, R. T., Lake, L. W., and Delliste, A. M., 2002, “Prediction of Capillary Fluid Interfaces During Gas or Water Coning in Vertical Wells,” SPE 77772, Proc. Annual Technical Conference and Exhibition, San Antonio, TX.
16.
Obigbesan, A. B., Johns, R. T., Lake, L. W., Bermudez, L., Hassan, M. R., and Charbeneau, R. J., 2001, “Analytical Solution for Free-Hydrocarbon Recovery Using Skimmer and Dual-Pump Wells,” SPE 66756/SPE 66536, Proc. SPE/EPA/DOE E&P Environmental Conference, San Antonio, TX.
Copyright © 2002
 by ASME
You do not currently have access to this content.