Hydraulic fracturing is the process that allows economic development of unconventional reservoirs. The process is very challenging and complex and is characterized by fracture propagation. New fractures are formed because of the stress field resulting from the stimulation of a fractured rock formation in a complex geological setting with discontinuities and interfaces, varying material properties, etc. These reservoir features impact in specific ways the stress field prior to and during hydraulic fracture propagation, and thus impact the final network of hydraulic and natural fractures that determine the shale permeability and outcome. One way to optimize the hydraulic fracturing process is for completion operators to know the stress field prior to stimulation so they can plan the position of the completion stages in areas where the stimulation will be favorable, allowing for complex fracture propagation.
This presentation focuses on the evaluation of the stress anisotropy resulting from the presence of natural fractures and facies in a reservoir. The geomechanical tool, Material Point Method, was used as a means of assessing the stress state in a fractured and heterogeneous media. The natural fracture network and the facies were evaluated using geostatistical algorithms. The resulting stress field, prior to stimulation, was characterized by strong variations resulting from the presence of natural fractures and facies in the study area. The stress field was demonstrated to vary from the regional stress in the vicinity of the fractures and facies and showed regions with high and low stress anisotropy.
Stress anisotropy is a key initial stress condition required by the completion engineers to successfully plan engineered stages targeting geological and geomechanical sweet spots, with low stress anisotropy.
See more of this Group/Topical: Topical 9: 4th International Conference on Upstream Engineering and Flow Assurance