Application of Horizontal Wells in Unconsolidated Reservoirs

Field tests show that screens in horizontal wells limit the sand production, but do not prevent the destruction of rocks in the reservoir. The analysis indicates geomechanical issues are constantly occurring in the reservoir. In the process of water cut development while waterflooding, a sharp increase in sand production indicates geomechanical issues have place not only in near-wellbore zone, but also in remote areas of the formation. As a result of the rock destruction in the channels of filtration between wells, there is an accelerated increase in water cut, a risk of a water bypass event arises. Negative geomechanical issues, enhanced by reservoir heterogeneity and viscous instability of the displacement front, lead to a sharp decrease in sweep efficiency and eventually to decrease in final recovery. The performed laboratory geomechanical experiments and combined geomechanic-hydrodynamic modeling allowed to estimate geomechanical risks for different geological settings and to develop optimal modes of horizontal wells operation in the conditions of unconsolidated reservoir of the field under consideration