Quadrant Energy has updated its evaluation and decided to drill deeper at its Roc-1 well, in the Greater Phoenix area offshore Western Australia.
The well was spud in November 2015 with the Noble Tom Prosser jack-up rig.
Carnarvon Petroleum, a partner in the project, previously reported a 25m reservoir zone.
According to Carnarvon’s project update issued on Wednesday, further drilling, from 4,380 to 4,420 metres, has revealed a 40 metres gross sandstone which contains indications of hydrocarbons. Light oil is present as inferred from mud log gas ratios, Carnarvon said.
The joint venture has proposed to deepen well to around 4,950 metres before undertaking wireline logging activities.
Carnarvon said that, since the last report, the 216 mm (8 ½”) hole has drilled from a depth of 4,435 metres to approximately 4,855 metres. As at 06:00 hours on December 23, 2015 the well was drilling ahead in the 216 mm (8 ½”) hole section at approximately 4,855 metres, the company added.
The partner in the project also said the joint venture was encouraged by the previously reported evidence of a working petroleum system in the current well, and the observations of good quality sandstone sections, to continue drilling below the previously announced target depth of 4,750 metres.
According to Carnarvon, it was expected to take at least another day to drill through to anticipated total depth of around 4,950 metres and condition the borehole for wireline logging. The information from the wireline logging tools was expected to take up to a further five to seven days to be obtained.
Carnarvon reported that the operator has proposed a suite of wireline logging including quad combo for resistivity and density/neutron measurements, formation pressure tools to determine fluid types (including fluid sampling) and pressure and mechanical sidewall coring tool to extract rock samples for later testing, the company said.
“The logging results are expected to provide additional information on, for example, the type of hydrocarbons present and the quality of the reservoir containing those hydrocarbons,” Carnarvon said.
The company further explained: “One use of this information will be for the estimation of hydrocarbon volumes recoverable. Given the characteristics of the reservoir it is envisaged that volume estimates could be completed within a reasonable period following the well being completed.”
Quadrant Energy is the operator of the licence WA-437-P with 40% interest, and its partners are Carnarvon Petroleum, JX Nippon and Finder Exploration, all holding 20% interest in the licence.