Comet Ridge spuds fifth coal seam gas well at Mahalo

Coal seam gas explorer Comet Ridge (ASX: COI) has spudded the fifth well of its latest evaluation drilling campaign at the Mahalo coal seam gas project in Queensland.

The company began drilling the Sirius Road-2 well on Friday and today reported it was currently being directionally drilled at a depth of 512m, headed for the Castor coal seam.

This well follows the Sirius Road-1 vertical well, which was drilled earlier this month and intersected a total net coal package of 6.9m including 3.3m in the Castor seam.

Sirius Road-2 was originally planned as a dual lateral intercept well, meaning it was planned to fork in two to intersect both the Castor seam and the Pollux coal seam below. Earlier in the month, Comet Ridge had successfully drilled its first dual lateral well 8.3km to the northwest of Sirius Road at Straun-3.

However, the Pollux seam intersected in the Sirius Road-1 well was found to be less than expected at only 0.9m in thickness. It was also thinner than the three adjacent offset wells and Comet Ridge said it was therefore “not considered representative of this part of the field”.

As a result, Sirius Road-2 is being drilled as a single lateral well and the testing of the Pollux seam will be deferred to a future lateral well “where a more representative intersection is encountered”.

Comet Ridge managing director Tor McCaul said the Sirius Road 1 and 2 wells provided the first production test opportunity of the deeper portions of the southwest part of the Mahalo gas project.

“We obviously would like to have both of the two main coals open in this test but having data from the key Castor seam will be invaluable in assessing the design and location of future follow-up work and will help the [joint venture] understand the size of the development,” he said.

Mahalo evaluation drilling

With an estimated 172 petajoules of 2P gas reserves, the Mahalo gas project in Queensland’s Bowen Basin is considered one of the largest undeveloped gas resources on the Australian east coast.

Comet Ridge is the exploration operator and holds a majority 40% stake in the joint venture project. It is partnered up with some of Australia’s biggest gas players, Santos (ASX: STO) and Australia Pacific LNG, which is 37.5%-owned by Origin Energy (ASX: ORG).

This current round of evaluation drilling started in October with the spudding of the vertical well Memoloo-2, followed by Straun-2 in November.

All three of the vertical wells in the program – Memoloo-2, Straun-2 and Sirius Road-1 – are planned to be completed with tubing and pumps then put on line for production testing to gain longer term flow data.

Last week, Comet Ridge announced that production testing of Memoloo-2 had been running for three weeks and “early signs are encouraging”.