Depletion of conventional reservoirs has resulted unconventional reservoirs to come into the play. However, conventional drilling and completion methods are not applicable for these reservoirs. The permeability of these reservoirs is about six orders of magnitude lower than conventional resources. As a result, unconventional drilling (drilling of multilateral horizontal wells in the direction of minimum horizontal stress), unconventional core tripping (optimization of core velocity depending on the porothermomechanical properties of the reservoir rock), and unconventional completion (simultaneous multistage hydraulic fractures perpendicular to the horizontal wellbores) are of paramount importance in order to obtain correct geomechanical data from these reservoirs and having the highest connectivity of the reservoir and the wellbore. In this dissertation, real geomechanical data exploited from different references for six different shale plays are reported. In addition, depending on the mineral content and their variation in each of these shale plays, the geomechanical property of each mineral, Voigt-Reuss-Hill averaging, and Monte Carlo stochastic algorithm, a set of porothermoelastic data are obtained and reported as mean values (the most probable value) and their standard deviation. Thereafter, FLAC3D fully coupled porothermoelastic simulation method is used for these six shale plays in order to determine the optimized core tripping velocity depending on the porothermoelastic properties (real and Monte Carlo). Finally, depending on three major factors as stress shadow effect, stress intensity factor, and aperture of hydraulic fractures, a robust semi-analytical geomechanical optimization methodology is presented for hydraulic fracturing of these reservoirs. Trip velocity optimization can be used in order to decrease the risk of core damage towards having accurate geomechanical data from intact undamaged cores. Moreover, the presented geomechanical optimization methodology can be used as input for reservoir simulators as ECLIPSE, Schlumberger in order to determine the best geomechanically optimized pattern with the highest production. Keywords : hydraulic fracturing, simultaneous multistage techniques, stress shadow effect (SSE), stress intensity factor (SIF), fracture aperture (FA), unconventional reservoirs; core retrieval; core damage; poroelasticity; porothermoelastic response; characteristic time; tripping velocity.
