ABSTRACT: High technology, low cost offshore exploration strategy for the new Millennium; offshore SE Sumatra PSC, Java Sea

Wight, Andrew W. R.¹, D. Roger Wall¹, E. J. Indrawan², Michael E. Ellis², and Alan Baker³
(1) YPF Maxus Southeast Sumatra BV, Jakarta, Indonesia
(2) YPF Maxus Southeast Sumatra BV
(3) PT Schlumberger Indonesia

The Offshore SE Sumatra PSC has been explored for over thirty years, finding 30 commercial oil fields having cumulative production exceeding one billion barrels. In such a mature phase, exploration appeared unattractive owing to prohibitively high cost for apparently low reward. A strategy was needed to balance the risk:reward ratio (cost:risked reserve potential) to encourage the exploration drilling necessary to maintain reserve growth.

This was solved by an expendable, 'slim-hole' drilling programme (dubbed 'MX'). A ten-well programme was designed that on a probabalistic risk analysis basis provided attractive net present value and rates of return. Costs were halved by utilizing three concepts; slim-hole, a built-for-purpose rig and truly integrated contractor services, using Schlumberger's new 'Bima', a highly-automated, self-propelled, self-elevating vessel designed for efficient moving, pre-loading, rig up/down operations. Economics were further improved by integrating with innovative production technological advances such as 'Guardian' monopod caissons. Close co-operation with Pertamina, in terms of 'streamlining' the approval process and allowing marginal field incentives on a case-by-case basis, was a key element to the success of the project.

To date, seven exploration wells (and 13 development/delineation wells) have been drilled, in record time and with extremely reduced costs. In addition the performance has exceeded predicted limitations on depth and other factors. Three of the exploration wells have so far encountered significant oil pay. If these prove commercial, the programme may be extended to larger-reserve, riskier ventures in the new Millennium.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia