Indonesia: Natuna well finds petroleum system

June 27, 2011
Premier Oil PLC said the Gajah Laut Utara-1 exploratory well in the Natuna Sea off Indonesia has established a working petroleum system on the Tuna block and is being plugged and abandoned with oil and gas shows.

By OGJ editors
HOUSTON, June 27
– Premier Oil PLC said the Gajah Laut Utara-1 exploratory well in the Natuna Sea off Indonesia has established a working petroleum system on the Tuna block and is being plugged and abandoned with oil and gas shows.

Gajah Laut Utara-1 went to a TD of 4,688 m in Pretertiary basement and encountered oil shows throughout a 350-m thick succession of interbedded sandstones and shales in the Oligocene, but logs suggest that the majority of the Oligocene sandstones are tight. One zone was sampled and gas was recovered.

The well also encountered good quality water-wet reservoir rocks within the Miocene sequence and source rocks within the Oligocene.

The Ocean General rig will move to drill the Belut prospect. Belut Laut is 10 km northwest of Gajah Laut Utara in a separate subbasin and is an independent test of the petroleum system on the Tuna acreage. The results of the Belut well are expected in early August.

Premier operates the Tuna block with 65% interest. Tuna is adjacent to the south of Block 07/03 off Vietnam in which Premier holds a 45% operated interest and southeast of Block 12W off Vietnam where Premier made the Dua and Chim Sao discoveries.