The main objective of this paper to is to discuss the recent finding on the formation anisotropy and lateral heterogeneity in the different hydrocarbon fields of onshore Abu Dhabi. The study was focused on Thamama and Wasia groups, mainly related anisotropy and spatial heterogeneity of the geomechanical poperties for reservoir characterization. This would have an impact on the stress variation and the definition of potential "sweet spots" for well placement optimization and identification of suitable completion methods.
The 1D Mechanical Earth model (MEM) is a description and quantification of rock elastic and strength properties, in-situ stresses and pore pressure as a function of depth, referenced to a stratigraphic column. The available wireline logs of several existing wells, including the compressional and shear slowness, stonely, bulk density, and gamma ray were used to compute log-derived elastic parameters, strength properties and stress components. Rock mechanics laboratory core plug tests were performed to calibrate the log-derived mechanical properties. Anisotropic modelling was applied to understand the anisotropy in elastic properties and horizontal stresses.
Integrating the 1D-MEMs indicate that Onshore Abu Dhabi Geomechanical properties (elastic and strength) and in-situ stresses vary laterally and vertically. Further, several mechanical layering and horizontal stress anisotropy can be identified. These results imply that the Wasia and Thamama reservoirs are susceptible to different fracturing mechanisms. Hence different fracture and faults sets can be predicted within the highly anisotropic deformation zones.
These findings significantly impact the exploration play concepts, where lateral variations are anticipated. This also applied to the production and development, where the stress barriers control the stimulation and completion strategies.