Predicting the fracture system in Shah Structure in Onshore Abu Dhabi using analogue modeling approach

This paper aims at predicting the fracture system associated with the structural development of the Shah Structure in relation to a deep-seated basement fault. It discusses the possible geometry, frequency and fracturing modes, and the development mechanism of the fracture system revealed throughout a set of analog models, which emphasize the link between the basement fault and the sedimentary cover in a timely manner construction. A 3D seismic data was used to construct a series of systematic scaled analogue models to reconstruct the structural evolution of Shah Anticline in association with an oblique sinistral strike-slip movement along basement fault, which induced both a strike slip movement in- and shortening of the cover sand layers. The deformation that was made by moving one of the basement plates in an oblique slip along the basement fault, resulted in an open anticline (box fold), which resembles the Shah Structure. Analog modeling results presented here reveal that fractures associated with the asymmetric anticline have developed in different locations, and possessed different geometries and modes. As anticipated, both tensile and shear fractures have developed in different areas within both the crestal parts of Shah Structure and within its limbs. However, the asymmetrical geometry of the model-anticline is reflected in the fracture distribution, trend and frequency. The steeper limb of the anticline bear more developed fractures than the gently dipping limb. The asymmetry of the anticline is not equally well displayed by the post-erosional units above the unconformity "model Simsima", where a gentler anticline is displayed. Hence within this gentle part of the model-anticline the fracture pattern is less developed, less frequent and evenly distributed. Such vertical and horizontal asymmetries in fracture pattern (geometry, frequency and mode) seen in these analog models are expected to have in reality developed in the Shah Structure. This new modeling approach has helped predicting the occurrence of different fracture system including geometry, frequency and fracture mode in different areas within Shah Structure. The predicted fractures have significant implications for exploration and field development plans of Shah Structure and those situated at the vicinity within Onshore Abu Dhabi.