| Reservoir suitable from UBD |
Reservoirs generally will not suitable from UBD |
| Under pressure / depleted formation or mature field. |
High pressure zones exhibiting high flow and potential control problem. |
| Dehydration formations exhibiting subirreducible water saturation or hydrocarbon saturation. |
High pore pressure coupled with highly permeable formation |
| High permeability (>1000md) consolidated intercrystalline sands and carbonates. |
Formation susceptible to spontaneous imbibition. |
| Formations containing significant concentrations of water-based mud filtrate-sensitive material (clays>1%), anhydrite. |
Hole section with various pressure. |
| Hard rock formation because of well bore stability. |
Formation where reservoir knowledge is poor. |
