Fluids and Rocks - Introduction to Carbon Capture and Sequestration - page 411

Figure 9.5.3 SEM image of a healed fracture
Scanning electron microscopy (SEM) image of a phyllosilicate-fi lled fracture (that could,
potentially, be reactivated as a preferential fl ow path) in the Eau Claire caprock (depth
2846 ft.), southwest Ohio. Image courtesy of Alexander Swift and Julia Sheets (Ohio
State University).

Abandoned
Well

Well Casting

Injection Well
CO 2

Cement
Fill Cluster of Producing

Oil Well

Vadose
Zone Flow

Formation
Rock

Cement
Well Plug

Upward
Flow

Updip Flow

Oil

Figure 9.5.4 Potential defects in cemented wells
Schematic fi gure showing potential defects that could cause wells to act as preferential
conduits for fl uid fl ow through seals. Figure redrawn from Nordbotten et al. [9.19].

attributes enhance the ability of rock fractures to heal themselves. This
tendency, though detrimental to the effi ciency of shale gas retrieval,
would be benefi cial to the security of the CO 2 -sequestration process.