Selection of Candidate Wells for Polymer Water Shut-off
Bourdelon Umeleuma Marcus1, Dulu Appah2 &Wilfred Chinedu Okologume3
1,2Department of Petroleum and Gas Engineering, University of Port Harcourt, Port Harcourt, Rivers State
3Department of Petroleum Engineering, Federal University of Petroleum Resources, Effurun, Delta State
Email:marcusbourdelon@gmail.com,dulu.appah@uniport.edu.ng,okologume.wilfred@fupre.edu.ng
Corresponding Author: Wilfred Chinedu Okologume
ABSTRACT
Water production challenges arise when water produced from an oil well is in excess, resulting to productivity decline and uneconomical oil production. This research focuses on the development of a pseudo-steady state model that will improve the selection of candidate wells with high water – oil ratio (WOR) for polymer water shut off treatment. This model is tested using production history data from five (5) wells (Well 1, Well 2, Well 3, Well 4 and Well 5) producing with a very high WOR and validated by comparing our results with conventional WOR and its derivative diagnostic plots. From the results obtained, Well 1 showed bottom water coning with late time channelling up to 1200 days after the first production started. Well 2 water problem was due to bottom water coning up to its 1000 days of production. Well 3 was significant with bottom water coning with late time channelling from the 900th day to 1530th day of its first production. Well 4 showed a water problem that is due to channelling. The excessive water production problem for Well 5 was as a result of bottom water coning which started from the 700th day to the1400th day after the first production. However, Well 1, Well 3 and Well 4 is candidate wells for polymer water shut off, as their channelling problems can be resolved by the selective use of coiled tubing to apply flowing gel (polymer) that can offer a relative permeability that is favourable to oil than water at the point of water entry. While Well 2, Well 5 are not candidate wells for polymer water shut off because their excess water production is due to producing too close to the water – oil contact (WOC) or above the critical rate. However, this study aimed at ranking wells with high water production problems and evaluating which well(s) are suitable for the application of polymer to mitigate the excessive water production problems.
Keywords: Coning, Channelling, Production, Pseudo-steady, Polymer
