Medco Energi reported in early April 2020 that exploration well Bronang 2, in the South Natuna Block B PSC Extension, West Natuna Sea, was a gas discovery. Operations at the well were likely completed in late March 2020, with results initially unreported.   Bronang 2, located in the Area I of the PSC, was likely spudded in mid-February 2020, using Japan Drilling's semi-submersible rig "Hakuryu-5". The well was likely targeting the Middle Miocene Arang Formation and Late Oligocene-Early Miocene Gabus Formation.  With the drilling of Bronang 2, the "Hakuryu-5" has completed the drilling contract with Medco. A second exploration well previously planned in the campaign has been likely deferred by Medco in view of the impact of the coronavirus disease 2019 (COVID-19) and the declining global oil price.  The first well in the structure, Bronang 1, was plugged and abandoned by Conoco in 1993 with oil and gas shows.  Prior to Bronang 2, the last exploration well drilled in the PSC was wildcat Tuna 1 in mid-August 2019. The well was plugged and abandoned as a gas discovery, likely targeting Pliocene sandstones of the Muda Formation. According to sources, well testing indicated biogenic gas with a flow rate of 4 MMcfg/d. The operator will conduct further study by running a series of lab analysis.  Tuna 1 is located in the unexplored Area VI of the PSC. The well was spudded around early July 2019 using the âCOSLBossâ J/U. The operator reported a cost of approximately USD 11 million for the well.  Medco may have also completed the Tuna 2 well in late 2019, to appraise the discovery of Tuna 1.  Medco completed a 1,400 sq km 3D seismic survey in the eastern part of the PSC (Areas V, VI and VII) in late 2018. ConocoPhillips, previous operator of the block, drilled one well in 1973 (Sokang 1, small gas discovery), in area VII of the PSC.  Medcoâs previous exploration well, SW Bawal 1, was completed in early November 2018. The well was drilled using âCOSLBossâ J/U and was reported to have flowed gas from the first DST, while the operator continued to stabilize gas flow. Additional tests were likely conducted, however further results have not been reported. SW Bawal 1 is located approximately 10 km southwest of the Bawal field (area I of contract block). The well was spudded in September 2018, possibly targeting the Upper Miocene-Lower Oligocene sandstones of the Gabus Formation.  The South Natuna Sea Block âBâ PSC is operated by Medco with 75% interest, through two subsidiaries. The other 25% is held by Prime Natuna Energy. The PSC is due to expire in 2028.    Background Information  The South Natuna Sea Block 'B' PSC was awarded to Conoco on 16 October 1968. A Signature Bonus of USD 7 million was paid with a work programme commitment of USD 14 million in six years. The contract originally covered a huge strip of 103,287 sq km across the Indonesian sector of the South China Sea between latitudes 03Â° 00' N and 04Â° 40' N and encompassing large parts of both East and West Natuna basins and the dividing Natuna Arch. The area was subsequently reduced to 14,907 sq km at the time of a contract extension signed on 3 August 1990. Under the terms of the initial contract, Conoco drilled a total of 64 exploration and appraisal wells and some 35 development wells between October 1968 and August 1990. It also shot a total of almost 40,000 line km of reflection seismic, 246 km of refraction seismic and recorded 3,828km of gravity data.   The exploration programme resulted in discoveries that were brought onstream as the Udang field (1981), the Kepiting field (1986) and the Ikan Pari field (1989), as well as several oil and/or gas discoveries deemed non-commercial at that time largely due to the lack of a gas market. All of these fields were relatively small, with Udang being the largest with recoverable reserves of 67 MMbo. The three fields were all off production by the mid-1990s. The largest discovery was made in December 1989 at Alu-Alu East 1. That well flowed at the aggregate rate of 12,289 bo/d, 187 bc/d plus 61.57 MMcf/d from Arang and Gabus Formation sandstones. The discovery was delineated in 1990 and quickly brought onstream in early 1993 as the Belida field. The field is believed to contain up to 370 MMbo plus 330 Bcfg recoverable (2P).   The PSC was granted a 20-year extension on 3 August 1990 to allow production to continue from the contract area. The extension became effective on 16 October 1998 and lasts until 16 October 2018 and was granted on the basis of payment of a new Signature Bonus of USD 3 million and commitment to a new work programme of USD 30 million in nine years. Two further part relinquishments in 1992 and 1997 have reduced the PSC to 11,162 sq km.   Between the award of the extension up to the end of 1997 Conoco drilled a further 16 exploratory and delineation wells, drilled 40 development wells and acquired 4,686km of 2D data and 2,097 sq km of 3D data, including the first 3D shot in the basin in a 207 sq km survey acquired in 1991.   Following a Letter of Intent signed in April 1997, on 12 July 1998 a Gas Sales Agreement was initialed between Pertamina and SembCorp Gas Pte Ltd of Singapore. This called for the delivery, under the West Natuna Gas Project, of 325 MMscf/d for 22 years from three adjacent PSCs, Conoco's South Natuna Sea Block 'B' PSC, Gulf's Kakap PSC and Premier's Natuna Sea Block "A" PSC. SembCorp Gas is utilising the gas for power generation and petrochemical projects in Singapore. Delivery is via a 469km, 28" diameter trunkline from West Natuna to Singapore. The project was completed ahead of schedule and gas sales to Singapore commenced in January 2001, well before the planned start date of 15 July 2001.  In order to accommodate the lifespan of the Conoco-led project, the three operating companies involved, Conoco, Gulf and Premier were granted extensions to their PSCs, these being announced simultaneous to the signing of the gas supply agreement on 15 January 1999. The Block 'B' PSC was extended to 2028 from its expiry date of 2018.  Since the conception of the gas project, ConocoPhillips has focused on delineating many of the earlier "non-commercial" gas or gas/condensate discoveries and increasing its gas reserves in the area through new wildcat drilling. From the start of 1998 to mid-2000, Conoco drilled some 18 exploratory and delineation wells and shot 619km of 2D and 2,710 sq km of 3D data. Seven development wells at Belida were drilled in the corresponding period. During this period, significant new gas discoveries were made at Belut West 2, Kaci 1, Keong 1 and Siput 1, and the earlier Belanak (1975), Belut (1975), Belut North (1974), Buntal (1990), Hiu (1979), Kerisi (1991), Tawes (1988) and Tembang (1981) discoveries were successfully delineated. Field development for the gas project has been the main focus of operations since 2000.  Gas produced from the block, through the West Natuna Transportation System, is sold to Singapore, following a 22-year sales contract started in 2001, and to Petronas' Duyong gas facilities, under a 20-year contract since 2002.  The latest field onstream in the block was Belut South. Gas production from the field commenced on 26 April 2014 with initial production at around 40 MMcfg/d. Production is tied back to the Belut North field. Total production capacity is around 120 MMcfg/d. The field is also producing LPG to Pertamina. The field development plan was approved in mid-2011. Belut South has recoverable gas (2P) of around 190 Bcf.
Indonesia (Penyu Sub-basin (West Natuna B.)) Belida