Introduction to Subsurface Containment

With recent high-profile incidents such as the Deepwater Horizon oil spill in the Gulf of Mexico and a natural gas leak in Aliso Canyon near Los Angeles, strategies for preventing containment losses are receiving increased attention. Containment has one main goal, to prevent leakage of production or injection fluids from their intended zones. In turn, prevention mitigates environmental damage, damage to assets and negative impacts on drilling and production. Subsurface containment requires a multi-faceted approach incorporating technical, geologic, and human variables.

Why It Matters

Subsurface containment benefits all parties. Operators see safer operations with higher revenues, and the public incurs lower risk of environmental damage or physical harm. Knowing the risks of established and emerging hydrocarbon recovery techniques and establishing programs to mitigate those risks is key to ensuring sustainable development.

Learning Objectives

  • Distinguish between wellbore integrity and subsurface integrity when discussing subsurface containment issues
  • Understand the difference between primary, secondary and tertiary well control
  • Explain basic well construction
  • Calculate the sacks of cement needed for a given example well
  • Explain potential environmental and safety challenges associated with the subsurface
  • Describe methods for evaluating the integrity of an injection well, including a Mechanical Integrity Test
  • Explain some of the risks associated with abandoned wells, specifically fluid migration
  • Describe how subsurface geology contributes to or hinders subsurface integrity
  • Explain how human and technical barriers can be conceptualized in the Bowtie Model of Risk Assessment and Mitigation

Images: “Aliso Canyon leak well pad 2” by Earthworks (23807396891) licensed under CC BY 2.0