After the Oyong Field discovery in 2001, Santos and its JV partners sanctioned feasibility studies in 2003. Nautec was engaged to provide a subsurface well engineering plan utilizing the adjacent disciplines to ensure life of well high flow efficiency and cost efficient completion and operational strategy.

The Client

Santos Pty Ltd

The Scope

  • Complete a comprehensive reservoir competency study
  • Recommend production tubing size, metallurgy and completion design
  • Develop a well operability strategy and provide intervention options
  • Formulate a completion strategy that will achieve the liquid (oil and water) and gas target rates of 10,000 stb/day and 44 MMSCFD respectively.

The Challenges

There were three oil wells to be drilled horizontally into the thin oil rim and two gas wells to be drilled in the gas cap. Reservoir geology dictated all production wells would require some form of sand control and fines were predicted to be very high, with the following development implications:

  • Possible compaction as pore pressure declines
  • Migration of fines
  • Potential flow of solids could be in significant quantities

These can potentially lead to:

  • Subsidence
  • Wellbore stretch – not all compaction transmitted to surface
  • Productivity decline
  • Borehole collapse / casing slumping
  • Solids production / erosion

The Innovation

In recognition of this requirement, Nautec undertook a comprehensive investigation of the well design focusing on available sand control technologies in order to determine the most appropriate type, secure the best hardware and develop a deployment strategy. Nautec were involved in the design of the laboratory experiments to test the applicability of each method of sand control. After reviewing the results from experiments the recommendation was for wire wrapped screen (WWS) offering 150um slots. This will provide a balance between solids restraint and limited plugging.

The Value Added

Nautec was able to provide Santos with long term life-of-asset well design and sand management strategy for the strategically important Oyong field. Nautec’s well design, workover and sand control management expertise provided the opportunity of reduced interventions & sand production for the Oyong Oil & Gas production wells.