Bass Oil Ltd (ASX:BAS) has increased its 1P proved net entitlement reserves at its Tangai Sukananti oil fields onshore Indonesia by 76% from 320,000 barrels at the end of December, 2017, to 505,000 barrels.
The update was due in part to increased production at the Bunian-3 well from de-bottlenecking operations and has provided a high confidence level to the substantial increase in 1P reserves.
De-bottlenecking operations are estimated to have boosted production from about 300 to more than 700 barrels of oil a day.
Net entitlement reserves are the share of cost oil and profit oil that Bass is entitled to receive under the joint venture signed with Indonesian state-owned corporation PT Pertamina.
Bass managing director Tino Guglielmo said: “The 76% increase in net entitlement 1P reserves is a strong demonstration of the Indonesian operation team capability and the strong underlying performance of the asset.
“Record production in 2018 and strong performance of the wells has moved reserves into the proved category from the probable.
“This increases confidence and value assigned to the asset moving into the period of development drilling in 2019 and beyond.”
Tangai’s 2P or proved plus probable reserves decreased by 2% due to 2018 production, from 670,000 barrels at December 31, 2017, to 602,000 barrels of oil.
Bass has also completed technical studies that provide a dynamic model which allows development scenarios to inform the 1P and 2P cases.
The total 2P field reserves at Tangai are estimated at 2.019 million barrels, including both the Bunian and Tangai fields.
Total 2C contingent resources are assessed to be 882,000 barrels of oil, comprising volumes attributed to currently producing or future planned wells.
Year-on-year movements show that while the overall level of reserves are similar, they have been firmed up into the 1P proved category as evidenced by the 113% and 76% increases in the field reserves and Bass net entitlement reserves, respectively.