Kutubu is Papua New Guinea's largest oil field. It came on line in 1992 and achieved peak rates of over 130,000 stb/d in 1993 before decline commenced in 1994. Capacity was still 45,000 stb/d at the beginning of 1998 but Kutubu production rates declined rapidly and half the field capacity was lost during 1998 to 2000. It was beginning to look in 2001 as if the field would be completely shut in within a few more years.

Kutubu was originally developed on the basis of a dynamic aquifer (or tilted contact) theory that was used to explain the apparent lack of oil along the northwest side of the field.

A field review conducted by the operator identified an alternate theory of compartmentalisation to explain the non-uniform oil column. As the alternate hypothesis was as good at explaining the early data and better at explaining some of the more recent performance, it was decided to abandon the original concept and test the new theory by drilling in areas the original concept would have predicted to be unprospective. Drilling results were conclusive-there was oil and little or no water in the centre of the field. Consequently, the compartmentalisation theory opened up a series of opportunities in areas that were previously considered unprospective due to the tilted contact concept, and a followup development campaign, along with other projects, has for four straight years completely halted the production decline. The field now appears to have a considerable remaining life of up to 2 decades.

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