Coro Energy buys into Mako gas field offshore Indonesia

Coro Energy has entered into an agreement to buy a 15 percent share in the Duyung offshore block in Indonesia, containing the Mako gas field. Coro will pay $4.8 million, and will also contribute $10.5 million for the 2019 drilling campaign.

The company will acquire the stake from West Natuna Exploration Limited (WNEL) which owns a 100% stake in the Duyung PSC. WNEL is owned by Conrad Petroleum (90%) and Empyrean Energy (10%).

Coro has said that the Mako gas field is an “extremely large,” shallow structural closure, with an area extending over 350 square kilometers.

The reservoir is a Pliocene-age sandstone, with a gas-water contact at approximately 391m true vertical depth sub-sea. The field has an excellent seismic definition with direct hydrocarbon indicators being very evident, Coro said on Monday.

Having been drilled but not tested by prior operators of the acreage, the commercial viability of the Mako gas field was demonstrated by the Mako South-1 well drilled by WNEL in 2017. The well was drilled to core and test the Mako reservoir, flowing up to 10.8 MMscf/d of dry gas on test. Overall four wells have penetrated the reservoir section, and while further appraisal is planned given the huge areal extent of the field, the reservoir distribution is reasonably well understood.

The Mako field is located in the West Natuna basin, approximately 16 km from the WNTS pipeline system which delivers gas from Indonesia to Singapore. Conrad has submitted a plan of development has been submitted to the Indonesian authorities and initial gas marketing discussions have started, resulting in a Heads of Agreement being signed with a buyer in Singapore for the Mako gas.

The operator’s current field development plan envisages an initial four-well development scheme, a small platform with compression facilities and an additional four wells as a second phase to be drilled later in the field’s life. The plateau production rate is envisaged to be up to 90 MMscf/d.

A series of prospects both beneath and above the Mako field have been mapped, Coro said. Of particular note is the Tambak prospect, a Lower Gabus structure that sits beneath the northern end of the Mako field. The target interval within Tambak exhibits seismic amplitude brightening, conformable with structural closure. The prospect has a prospective resource range of 200 to 300 Bcf with a mid-case 250 Bcf and a CoS of 45%.

At the southern end of the field, over the structure’s crest, sits the Mako Shallow prospect.

“This again shows very strong direct hydrocarbon indicators on seismic, conformable with closure in shallow Muda sandstones. The Shallow Muda prospect has the potential to add a further 100 Bcf of recoverable resources and a very high CoS of 75%. A drilling campaign is being planned for 2019 and a test of the Tambak prospect is to be a part of the program,” Coro said on Monday.

“Following on from Coro’s entry into the Bulu gas field earlier this year, the Company’s next step is directly in-line with its strategy of building a SE Asian portfolio of fields with associated exploration upside. Coro intends to further build on these positions in the East Java and West Natuna basins and to continue to seek out these value accretive deals,” Coro said.