Fractures

Is the fracture natural or induced ?

Is the fracture natural or induced ?

When creating a fracture density log, be sure not to include induced fractures (by coring, handling etc). This blog outlines the main criteria I use to differentiate between natural and induced fractures in rock core.

Classification of Naturally Fractured Reservoirs

Classification of Naturally Fractured Reservoirs

Fractured reservoirs are often dual porosity systems where the fractures provide an additional porosity to the matrix. Nelson provides a valuable classification of fractured reservoirs based upon relative contribution of matrix and fractures to porosity and permeability.

Deformation bands & later open fractures, Clair Field

Deformation bands & later open fractures, Clair Field

Deformation bands (permeability reducing) and open fractures (enhancing) can co-exist in a sandstone reservoir but owing to timing (the d-bands form early during burial), the open fractures can still assist or provide essential reservoir permeability.

Cemented fractures: good or bad news ?

Cemented fractures: good or bad news ?

Cemented fractures are often bad news for hydrocarbon production but a partially filled fracture network can be benefical..