Abstract

One of the objectives of the Arun Reservoir Management Plan is to develop the eastern flank area, which is unswept by injection gas and consequently to produce gas with a higher condensate yield than the main body of the field.

The production of the Arun field is maintained by several dry-gas injection wells. Most of these are located along the western flank, with the rest in the northern and southern areas. There are no injection or producing wells on the eastern flank.

The remapping in 1985 for the Arun Reservoir Management Study extended the eastern limit of productive carbonate. The COSMOS simulation study which followed identified an opportunity to produce richer gas from this eastern flank. The current reservoir study indicates the absence of the highly permeable uppermost zone in this region and consequently a reduced risk of rapid gas - breaktrough.

Three eastern flank wells, C-II-12, C-I-12 / C-I-12A and C-III-13 were successfully drilled in the period from December 1988 to the present. The results indicate that the uppermost, high permeable zone is thin to absent in this area but nevertheless show reasonably good reservoir quality. Production test rates in these wells varied from 80 to 120 MMSCFPD of gas at 1900 psig well-head pressure with CGR's of above 60.

Eastern flank development results to date have confirmed expectations and are helping meet reservoir management objectives. Two more eastern flank wells will be drilled in 1990.