On 26 July 2019, Indonesian Ministry of Energy and Mineral Resources (MEMR) offered the West Tanjung I exploration block, located onshore in the Barito Basin, under the Conventional Oil and Gas Bidding Third Round 2019. Access to bid documents is scheduled from 26 July 2019 to 18 October 2019. Submission of participating documents is from 18 October 2019 to 25 October 2019 at 2.30 pm (Western Indonesian Time).  The data package for the West Tanjung I block comprises approximately 2,850 km of 2D seismic data (vintage from 1974 to 1986) and five well data. As an incentive to participate to the bidding exercise, free access to the data package will be granted to all companies that purchase the bid document for the related block. The data package will be only charged to the eventual winner of the block.  The minimum signature bonus for the block will be USD 2.5 million. Minimum firm commitments for the first three-year exploration period include G&G studies and 600 km of 2D seismic acquisition and processing. The contract will require a mandatory relinquishment of 25% of the block area at the end of the third year.  The block, covering an area of approximately 5,460 sq km, is situated onshore in the North Barito Deep Sub-basin. Seven wells have been drilled within the offered acreage but none of them was successful. BPM drilled two shallow wells that were dry, Rudji 1 (922 m) in 1938 and Buntok 1 (863 m) in 1939. Union Oil under the Teweh PSC drilled three wells, Montalat 1 (1,055 m, oil shows) in 1979, Panran 1 (1,698 m, oil & gas shows) in 1980, and Perigi 1 (824 m, dry) in 1980. Unocal in 1989 under the Teweh PSC drilled Ahmatan 1 (3,054 m, dry) and Buntok Baru 1 (1,530 m, oil shows).  The majority of the West Tanjung I block was previously covered by the West Tanjung PSC operated by PT Karya Inti Petroleum between 2011 and 2018.    Typical source rocks identified in the Barito Basin are coals and shales from the Tanjung Formation and Lower Warukin Formation. The Total Organic Carbon (TOC) in these formations ranges from 0.6 to 5.4 wt% in the shales, and from 43.6 to 65.9 wt% in the coals. The main reservoir in the basin is provided by clastic sediments of Upper Paleocene to Middle Eocene Lower Tanjung Member, with porosity ranging between 15% and 26%. The pre-Tertiary basement has also been identified as an oil reservoir in the Tanjung field. Another potential reservoir is the Upper Oligocene-Lower Miocene carbonates of the Berai Formation  Reportedly, several prospects and leads have been identified, likely from previous seismic data. The most prospective lead identified in the area is the Palas Dua lead, with P50 resources (unrisked) of 44.3 MMbo or 213 Bcfg and P50 (risked) of 5.4 MMbo or 26.5 Bcfg within Lower and Upper Tanjung members.  Background Information  West Tanjung PSC    The previous West Tanjung block was offered on 20 May 2011 as part of the First Petroleum Bidding Round 2011 under the direct offer mechanism. The preliminary award/announcement of winning bidder was made on 21 September 2011, when the block was awarded to PT Karya Inti Petroleum. Firm commitments for the first three years of exploration included G&G studies (USD 1.1 million) and 250 km 2D seismic acquisition (USD 2.5 million). Signature bonus paid for the block was USD 1.0 million. The block was also subjected to partial acreage relinquishment of 25% of the total acreage size after the expiry of the first exploration period.  The block covered an area of 6,095 sq km in the North Barito Deep Sub-basin (Barito Basin). Portions of the block were previously covered by the UEP IV contract (Pertamina) from 1966 to 1992, Teweh PSC (Union Oil) from 1974 to 1983, Teweh PSC (Unocal) from 1985 to 2000 and North Tanjung PSC (PerminTracer) from 1993 to 2002.   In mid-September 2013, PT Karya Inti Petroleum offered farm-in opportunity up to 49% participation interest in the block.    A 200 km 2D seismic acquisition was being planned in 2016, subject to outcome of the drilling results in 2015. In case of unsuccessful drilling results, the operator could have acquired 2D seismic data focused on different prospects in 2016. An additional exploratory well was planned to be drilled in 2017, with an estimated cost of around USD 5 million.  The plan was later cancelled as the block was reported by SKK Migas to be under relinquishment in January 2018. The seismic survey would have focused on the limestone of Upper Oligocene to Lower Miocene Berai Formation and syn-rift stratigraphic play of Eocene Tanjung Formation. The pre-Tertiary Basement could have provided an additional exploration target for the survey.
On 26 July 2019, Indonesian Ministry of Energy and Mineral Resources (MEMR) offered the West Tanjung I exploration block, located onshore in the Barito Basin, under the Conventional Oil and Gas Bidding Third Round 2019. 