E&P Notes (May 2021)
Authors: JPT staff _ 
Published: June 2021

Dugong Reserve Estimate Tightens on New Well Results

Neptune Energy redefined the estimated reserves at its Dugong discovery in the Norwegian sector of the North Sea to between 40–108 million BOE based on the results of appraisal well 34/4-16 S. Prior to this appraisal, the operator believed the prospect could hold as much as 120 million BOE. The main objective of the well was achieved by establishing the oil/water contact. Neptune Energy said the new range will be subject to further detailed analysis and review, and a drillstem test on the well is planned at a later stage.

The appraisal well was drilled using the Odjfell-operated semisubmersible Deepsea Yantai in about 330 m of water.

The Dugong discovery will either be linked to nearby infrastructure or developed as a standalone development. Dugong is located 158 km west of Florø, Norway, and is close to the existing production facilities of the Snorre and Statfjord fields. The Dugong license partners are Neptune Energy (operator and 45%), Petrolia NOCO (20%), Idemitsu Petroleum Norge (20%), and Concedo (15%).

Oselvar P&A Work Underway

Decommissioning of the DNO Norge-operated Oselvar field has kicked off with the operator contracting semisubmersible Borgland Dolphin for plug-and-abandonment work. Oselvar is in the southern part of the Norwegian sector in the North Sea, 20 km southwest of the Ula field. The water depth is 70 m. Oselvar was discovered in 1991, and the plan for development and operation was approved in 2009. The field was developed via a trio of subsea wells tied to Ula. Production started in 2012 and ended in 2018.

The Borgland Dolphin was moved to the field on 20 March. The rig recently went through a series of upgrades including the installation of new shale shakers, new standpipe manifold, an upgraded drilling control system, and an upgraded helideck.

Decommissioning must be completed by the end of 2022.

Equinor Green Lights FPSO for Brazil’s BM-C-33 Development

Equinor, together with license partners Repsol Sinopec Brasil and Petrobras, have approved an FPSO-based development concept for BM-C-33, a gas/condensate field located in the Campos Basin pre-salt in Brazil.

Subsea wells will be tied back to the FPSO located at the field. Gas and oil/condensate will be processed at the floater to sales specifications and exported. Crude will be offloaded by shuttle tankers and shipped to the international market after ship-to-ship transfer. A newbuild hull has been selected to accommodate the field’s planned 30-year lifetime.

“BM-C-33 holds substantial volumes of gas,” said Veronica Coelho, Equinor’s country manager in Brazil. “A completion of the ongoing liberalization of the natural gas market in Brazil in line with the current plan, is key for the further development of the project. BM-C-33 is an asset that can generate value for the society, both through the creation of direct and indirect jobs, ripple effects, and through a gas supply that can induce industrial growth, as has happened in other countries.”

Gas export capacity is planned for 16 million cubic meters per day with average exports expected to be 14 million cubic meters per day. Daily oil processing capacity is of 20,000 cubic meters per day.

The gas-export solution is based on an integrated offshore gas pipe-line from the FPSO to a new dedicated onshore gas-receiving facility inside the Petrobras TECAB site at Cabiúnas, before connecting to the domestic gas-transmission network.

Lundin Makes Small Discovery Near Edvard Grieg

Lundin Energy Norway encountered a 10-m oil column with its wildcat well 16/4-13 S about 15 km south of the Edvard Grieg field in the central part of the North Sea. The operator added that about 7 m of the encountered column was of moderate to poor reservoir quality.

The oil/water contact was encountered 1950 m below the sea surface. The entire reservoir, including the water zone, comprises conglomeratic sandstones in a thickness of about 380 m.

Preliminary estimates place the size of the discovery between 0.5 and 1.4 million cubic meters of recoverable oil equivalent. The licensees will assess the discovery regarding a possible tie-in to the Solveig field.

The well was drilled by Seadrill semisubmersible West Bollsta and will be permanently plugged and abandoned. The rig will now move to drill the 16/4-BA-1H production well on the Solveig field.

Wintershall Gets Permit for Bergknapp Appraisal

The Norwegian Petroleum Directorate granted Wintershall Dea Norge a drilling permit for well 6406/3-10 A to spud a follow-up probe to a discovery made in April 2020. The Bergknapp appraisal will be drilled from the Odjfell semisubmersible Deepsea Aberdeen once the rig has concluded the drilling of wildcat well 6507/4-2 S for Wintershall in production license 211.

The Bergknapp appraisal will be drilled about 8 km west of the Maria field in the Norwegian Sea. The discovery well 6406/3-10 intersected an oil column of at least 60 m in the Garn formation and an oil column of at least 120 m in the Tilje formation.

Preliminary estimates of the Bergknapp discovery indicate it could hold between 26–97 million BOE.

The find is in production license 836 S where Wintershall is the operator and holds a 40% stake. The other licensees are DNO Norge (30%) and Spirit Energy Norway AS (30%). The area in this license comprises parts of Blocks 6406/2 and 6406/3.

Guyana Says Liza Hits First-Phase Capacity

Guyana’s President Irfaan Ali announced that the first phase of the Liza offshore crude project had achieved its intended full-production capacity of around 130,000 B/D.

Ali told virtual attendees at the Guyana Basin Summit that he expected an additional 10 exploration and appraisal wells to be drilled off Guyana this year. He said the second phase of the Liza project, operated by ExxonMobil, would begin in 2022.

The consortium led by Exxon, which includes partners Hess and CNOOC Ltd., has made 18 discoveries containing more than 8 billion bbl of recoverable oil and gas in Guyana’s Stabroek block.

Equinor and Partners in Barents Bounty

Equinor and partners Vår Energi and Petoro have struck oil in exploration well 7220/7-4 in production license 532 in the Barents Sea. Recoverable resources are so far estimated at between 31–50 million BOE. The well was drilled about 10 km southwest from the well 7220/8-1 on the Johan Castberg field.

“Succeeding in the Barents Sea requires perseverance and a long-term perspective,” says Nick Ashton, Equinor’s senior vice president for exploration in Norway. “This discovery strengthens our belief in the opportunities that exist, not least around the Castberg, Wisting, Snøhvit, and Goliat areas.”

The well, drilled by semisubmersible Transocean Enabler, struck 109 m of oil in the Stø and Nordmela formations. The top reservoir was encountered at a vertical depth of 1788 m below sea level. The expected gas cap was not encountered in the well.

The well was not formation tested, but extensive data acquisition and sampling took place.

Equinor said further development of the discovery toward the planned infrastructure for the Johan Castberg field will be considered at a later stage.

Exploration well 7220/7-4 is the first of four planned exploration wells for Equinor in the Barents Sea this year.

Eni Strikes Light Oil at Cuica

Eni has made a new light-oil discovery in Block 15/06 at its Cuica prospect in the deep waters offshore Angola. The prospect is located inside the Cabaça Development Area and close to the Armada Olombendo FPSO (East Hub). Eni estimates Cuica could hold between 200 and 250 million bbl of oil in place.

The Cuica-1 NFW was drilled as a deviated well by Seadrill-operated drillship Sonagol Libongos in 500 m of water and reached a total vertical depth of 4100 m, encountering an 80-m total column of reservoir of light oil (38 °API) in sandstones of Miocene age with good petrophysical properties. The discovery well is going to be sidetracked up-dip to be placed in an optimal position as a producer well. According to Eni, data collection from the well indicates an expected production capacity of around 10,000 BOPD.

Cuica is the second significant oil discovery inside the existing Cabaça Development Area. The well location, intentionally placed close to East Hub’s subsea network, will allow a fast-track tie-in of the exploration well and relevant production. Eni expects the well could be on line within 6 months.

Following the discoveries of Kalimba, Afoxé, Ndungu, Agidigbo, Agogo and appraisals achieved between 2018 and 2020, Cuica represents the first commercial discovery in Block 15/06 after the relaunch of the exploration campaign post-2020 COVID-19 pandemic. The discovery confirms the exploration potential of the block. A 3-year extension of the exploration period of Block 15/06 was recently granted until November 2023.

The Block 15/06 joint venture comprises Eni (operator, 36.8421%), Sonangol P&P (36.8421%), and SSI Fifteen Ltd. (26.3158%).

No Injuries Reported in West Mira Incident

An equipment failure onboard Northern Ocean semisubmersible West Mira resulted in production equipment descending to the seabed. The rig owner said no one was injured and the well at the location was secured “with three barriers in place.” The unit was in the process of lowering the equipment on the Wintershall-operated Nova field.

“While lowering a x-mas tree from West Mira, the winch wire snapped when the tree was five meters below the sea surface. The x-mas tree sunk to the seafloor 368 meters below water level. Eight people were working in the area of the rig where the incident occurred in safe distance from moving equipment,” said Wintershall.

The rig manager, Seadrill Europe Management AS, and Wintershall are conducting investigations into the incident and have agreed to a plan to secure the production equipment.

“A remote operated vehicle (ROV) was sent to the seafloor to assess the situation,” added the oil company. “The ROV survey showed no risk of discharge of well fluids or hydrocarbons and the x-mas tree has been localized on the template.”