Incremental recovery using dual-completed wells in gas reservoirs with bottom water drive: A feasibility study

Document Type

Conference Proceeding

Publication Date

1-1-2018

Abstract

Water drive reduces gas recovery though the mechanism of water coning that results in liquid loading and killing the wells. Installation at a Downhole Gas Water Separator (DGWS) in the well may prevent the liquid loading. The paper presents another solution to this problem - a dual-completed well with downhole water sink (DWS) drainage and injection installation. DWS wells are different from the DGWS wells by inclusion of a second bottom completion that controls water outside the well and prevents commingled inflow of gas and water to the top completion. The wells have been successfully tested in oil reservoirs. The study qualifies DWS concept for gas wells by comparing simulated performances of a conventional well, and a DWS well. The simulation runs were made over a broad range of the initial reservoir pressure and permeability values for a gas reservoir with large associated aquifer. Also included is a comparison between DGWS and DWS wells for selected conditions. The results show considerable advantage of dual completion over conventional wells in low-pressure (subnormal) tight (1 md) reservoirs - a 2.6 - fold recovery increase before killing the well with water. The advantage, however, reduces to 10% for reservoir with normal pore pressure gradient and permeability 10 md. When compared to DGWS wells, the final gas recovery of DWS wells is the same, but DWS produces all the gas 35% sooner than DGWS. The study also identified the best DWS completion design where the top completion is used only for gas production, and the bottom completion for inverse gas coning, gravity separation and water injection.

Publication Source (Journal or Book title)

Canadian International Petroleum Conference 2003, CIPC 2003

This document is currently not available here.

Share

COinS