Fractured Reservoirs: An Extensive Geomechanical Integrity Approach

Abstract

There is no more challenging task for today’s oil and gas production companies than simulating the production behavior of naturally fractured reservoir fields. These reservoirs are highly prosperous at their early production stage, only to decline afterward. The previous behavior has raised awareness of the geomechanics role in controlling the deliverability of those reservoirs. This is not a straightforward rock mechanics problem to tackle as it requires dealing with two constituting continuums, matrix and fractures; they respond differently to solicitations. Hasdrubal is a naturally fractured reservoir field located offshore Tunisia. Recently, the area has manifested profound integrity and water coning issues. An integrity study was necessary to accurately determine the ever-changing stress settings and assimilate their impact on the production trend. Thus, former geomechanical investigations of the field were revisited to acquire a strong understanding of the reservoir and develop an appropriate three-dimensional geomechanical model (3D-GM) that incorporates the invasive impacts of faults/fractures on the mechanical and hydraulic behavior of the field. The 3D-GM was initially deployed to appraise the alteration of the governing stresses and strain setting induced by the reservoir depletion before generating a potential reactivation map of the faults at current and future conditions.