In situ stresses and hydraulic fracturing in Hassi Messaoud Reservoir, Algeria

Abstract

Understanding the rock mechanics aspects of Hassi Messaoud (HMD) reservoir is extremely important not only for hydraulic fracturing purposes but also for planning horizontal well drilling and completion. Analysis of the data generated from the hydraulic fracturing experience in Hassi Messaoud shows that fracturing is strongly lithology dependent. The magnitude and the orientation of the stress characterize the stress field. The stress magnitude in HMD is correlated to Young's modulus and shaliness. A new correlation is proposed relating minimum horizontal stress, shaliness and porosity.

The stress field orientation in Hassi Messaoud fits that observed in other locations throughout Algeria. The maximum principal stress is in the azimuth direction between 135-140° azimuth, perpendicular to HMD anticline trend. The iso-fracturing gradient map of HMD structure confirms the compartmentalization of the reservoir into two compartments , the eastern and the western compartments, the former having, relatively, low fracturing gradients and the latter having higher fracturing gradients. The results of this study could be used in the selection of candidate wells for hydraulic fracturing as well as planning horizontal well drilling and completion.