UKCS: Dana Petroleum applies for Platypus developmentSource: Pixabay

UKCS: Dana Petroleum applies for Platypus development

Dana proposes to develop the Platypus field by drilling two subsea production wells (plus one contingent on the Platypus well performance) tied back to a new Platypus subsea manifold.

Dana Petroleum sent a letter of application to the OGA for the development of the Platypus field as following:

  • The primary nature of the project will be the installation of a subsea manifold and a gas export pipeline to the Cleeton platform
  • Two development wells will be drilled and connected to a subsea manifold; the field will export gas, condensate and formation water to the Cleeton CW platform via a 23 km pipeline
  • The Platypus pipeline ties into the Perenco operated Cleeton CW platform that is bridge-linked to the manned Cleeton CP platform
  • *Mid case technical recoverable reserves from Platypus of 18.5 MMboe
  • *Platypus East (previously Possum) provides significant upside to the Platypus project, potentially adding up to 9 MMboe reserves to the project
  • *Platypus East is estimated by the operator to have a Geological probability of success (GPos) of 73%
  • *Platypus alone is expected to produce 47 million cubic feet of gas per day (“MMscfd”) at peak production, according to operator estimates
  • *The anticipated producing life of the field is approximately 20 years
  • *Platypus was flow tested in 2012, following a successful appraisal well, at a rate of 27 MMscfd (approximately 4,600 barrels of oil per day on an equivalent basis)

*Development plan submitted for Platypus gas project, October 15th 2019

Indicative subsea layout for the Platypus Development. Source: Dana Petroleum, Environmental Statement for Platypus Field Development

The anticipated duration of drilling is approx. 6 months with installations and pipe-lay taking approx. 3 months. The anticipated life of the project is 20 years from the date of first gas.

Drilling of the Platypus wells is expected to commence in Q2 2021 and be completed by Q2 2022; first gas will be achieved from the first completed well at the earliest in Q4 2021, while drilling of the other well is ongoing. The Platypus reservoir is expected to be uniform in nature and the two wells will, therefore, be of a similar design.

The proposal is made on behalf of all license members: Dana Petroleum (E&P) Limited (59%), CalEnergy Gas Limited (15%), Parkmead (E&P) Limited (15%) and Zennor North Sea Limited (11%). Dana is the appointed Operator of the Platypus field as part of a co-venture between CalEnergy, Parkmead Group and Zennor Petroleum.

Platypus Field

Platypus is a gas field located approximately 65 km northeast of Easington in Block 48/1a of the southern North Sea and 121 km from the UK/Netherlands median line. Platypus was discovered in 2010, 48/1a-5 discovery well. A further appraisal well was drilled in 2012, 48/1a-6.

Location of the Platypus Development in the context of the UKCS. Source: Dana Petroleum, Environmental Statement for Platypus Field Development

The target reservoir is the Permian Rotliegend Group Leman Sandstone Formation with the hydrocarbon-bearing reservoir located approx. 3100 m below sea surface.

The Platypus reservoir will be developed with long sub-horizontal wells and will be produced under natural depletion.

The Platypus reservoir contains gas at reservoir pressure and temperature conditions that are higher than atmospheric conditions at the surface. At surface conditions, the reduction in pressure relative to reservoir conditions will result in some liquid hydrocarbons dropping out of the gas solution.

The initial liquid yield is expected to be approximately 3 bbl/mmscfd per day. The hydrogen sulphide (H2S) and carbon dioxide (CO2) levels are estimated to be low at a maximum of 0.2 ppm and 1.26 mol% respectively.

Total gas production from the Platypus wells will reach the highest production rate in the first full year of production (2022) at approximately 2.1 million Sm3 per day annual average before steadily declining over field life. Total condensate production from the Platypus wells will also peak in the first full year of production at approximately 28.1 Te/d annual average before steadily declining over field life.

Letter of application