Abstract
Laminated sandstone reservoirs of 5 m or less in thickness with low permeability and low reservoir pressure in a North African Devonian formationr conventionally require hydraulic fracture stimulation after selective perforation to provide economically attractive production results.
A recent perforating program performed with guns deployed by wireline and tubing conveyance in two Devonian wells followed an engineered perforation design and provided the best gas flow rates ever measured for this formation even without any further fracture stimulation.
Although formation pressures at about 1300 psi were at a marginal level for the application of dynamic underbalance perforating technology, the perforating design considered the downhole dynamics and theoretical wellbore hydraulic movement, ensuring successful job design. Well testing analyses conducted on both wells after the perforating program provided an estimation of permeability-height and skin and indicated no need for fracture stimulation.
This paper describes the formation, reservoir, and well parameters as well as the perforating program and well testing results that provided a flow rate of 16.7 MMscf/D dry gas through a 96/64-in. surface choke.
