BTG field is a heavily faulted and compartementalized heavy oil producing field located in central Sumatra, Indonesia. Currently the field has aproximately 60 producing wells from reservoirs at depth varying from more than 100 ft to nearly 700 ft TVD. Eventhough all wells have been artificially lifted, the field still has low oil recovery at 12% from 150 millions originally oil in place. Cyclic steam stimulation (CSS) has been applied in this field since 1977 on a single well basis to improve heavy oil production. This paper is to review both technically and economically on several CSS jobs in BTG field. This will helps engineer to obtain optimum results for CSS jobs. Six CSS wells is evaluated in this study. The jobs was run sequentially for each well from March until July 2015, and currently those six wells has been produced after injection and soaking period. Production performance after jobs was observed and compared with those pre-jobs performances. Key parameter that describes good production performance were defined as post job initial rate and decline rate. Gain from offset wells during injection period was also observed in this study. Several offset wells with up to 250 ft spacing show production increase because of steam propagation. Those observation, finally, are used to evaluate CSS production contribution and economical aspect of CSS jobs in BTG field.
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