GeoContainment™ is the containing of subsurface operations within their designed system. The term is used in the Petroleum Industry relating the subsurface containment of thermal recovery project such as Steam Assisted Gravity Drainage (SAGD) or Cyclic Steam Stimulation (CSS). It is a vast subject involving the study of geology, geomechanical properties, reservoir parameters, in-situ stresses, and changes in thermal / stress fields during operation. The concept of GeoContianment™ is also applicable to Solution Mining and Salt Caverns which involve storage of different materials or hazardous wastes underground.
Thermal in-situ recovery involves injecting steam into a reservoir at high pressure in order to mobilize and recover the heavy oil/bitumen. Rock layers directly above these types of reservoirs are known as the caprock. The caprock is a non-permeable formation overlying a reservoir or storage cavern acting as a seal. In order to control the mobility of steam, bitumen, waste or formation fluid, the caprock must display sufficient hydraulic and mechanical integrity to withstand injection pressures in an in-situ production or subsurface storage/disposal scheme. Evaluation of the underburden seal is also important in some applications to ensure complete GeoContainment™.
In recent years the number of caprock failures in the oil sands and collapses in salt caverns has made subsurface GeoContainment™ critical for public safety and environmental protection.