Burn Efficiency

Boots & Coots data reduction and synthesis algorithm, hardware design, systems engineering and project management combine to address unique well-control challenges related to characterization and prediction of turbulent, multi-phase, hydrocarbon flow. To prove that a Worst Case Discharge from a blowout well would remain ignited after flow-field combustion (with and without fluid structure interactions) and to calculate the percentage of hydrocarbons that would not be combusted, Boots & Coots has developed a robust model that determines:

  • Burn efficiency, defined as the ratio of hydrocarbons combusted to total oil
  • Blowout flame radiant heat flux
  • Mass flux and heat content of unburned residual
  • The liquid carryover and spatial distribution of unburned residual that would have to be recovered with spill response equipment.

Our research integrated extensive field-based blowout experience (including evaluation of our blowout database) with aerospace engineering expertise, which includes numerical modeling using computational fluid dynamics, to accurately validate burn efficiency numerical modeling results. The numerical model validated the presence of complex supersonic shock structures and calibration data for the development of the engineering burn efficiency methodology.

Features and Benefits:

  • Three-phase wellbore flow modeling to account for potential water production and corresponding variation in gas-to-oil ratio (GOR) for anticipated release conditions, particle break-up, soot production and flame stability;
  • Subsonic multi-phase hydrocarbon combustion to establish the range of conservative burn efficiency for anticipated release conditions;
  • Lower range GOR impact on burn efficiency;
  • Analysis of conditions across the producing life of the well (varying GOR and water content), in addition to computing burn efficiency for worst-case discharge;
  • Discerniable burn-efficiency results for the range of blowout conditions that correspond with realistic release conditions.
Parametric analysis of key variables has been established to provide a measure of the burn efficiency margin and the robustness required for regulatory approval of any given spill response plan.