Troubleshooting Mature Waterfloods
There has been quite a number of informative papers published recently describing sea water injection facilities for fields such as BP’s Fourties (Ref. 1) and Chevron’s Ninian (Ref. 2) in the North Sea and GUPCO’s E1 Morgan in the Gulf of Suez (Ref. 3). Those waterfloods described were for relatively new developments, with reservoir permeabilities varying from 100–2,000 millidarcies. They are generally recognised as being successful floods, although each author notes various operating problems caused, for example by corrosion, scale formation and bacterial fouling.
This paper attempt to provide a logical approach to identifiying the essential causes of operating problems encountered in a waterflood. These problems can have a dramatic effect on the economics of oil production, particularly for older floods and with tighter formations, where permeabilities may be around 1–10 millidarcies or less.