Indonesian oil & gas exploration and production company Conrad Petroleum has flowed dry gas from its Tambak-1 well located in the Duyung PSC in the West Natuna Basin, offshore Indonesia.
The Tambak-1 well was designed to both appraise the Mako gas field and test the underlying Tambak exploration prospect. Coro Energy plc holds a 15% interest in this project.
The drill stem test (DST) flowed dry gas from the intra-Muda sands at a rate of 11.4 MMcf/day on a 181/64-inch (2.8 inches) choke, maintaining a wellhead tubing pressure of 225psi. The DST of the Tambak-1 well was completed with cased hole perforations along with a 6-foot interval.
The DST demonstrates that this completion method is viable, has resulted in the maximum flow rate mentioned above, again confirming the deliverability of the Mako reservoir.
Cased hole perforation is simpler and a more cost-efficient completion method than the open-hole screen completion used to successfully test the Mako South-1 well (located 4.9 km from Tambak-1) in June 2017.
Tambak-1 encountered a very well-developed 56 feet thick sand package of high permeability and good porosity, significantly thicker than the 33 feet of pay discovered in Mako South-1.
The Tambak-1 well intersected the intra-Muda reservoir (Mako gas field) at a depth of 1,276 feet sub-sea, and Conrad recovered a full suite of wireline logs, together with a pressure survey and fluid and gas samples.
With the better-than-expected flow test, the data confirmed that the Mako gas field is a very large (350 km2), an aerially extensive “single tank” field, supporting the conclusions from the recently drilled Tambak-2 well, over 17 km from Tambak-1.