Tectonic Map of Abu Dhabi, UAE

摘要

The study of tectonics deals with the broad architecture of the outer part of the Earth, the age, relationship, evolution of regional structural, deformational, and crustal features. Subsurface geological maps are perhaps the most important tool used to explore for undiscovered hydrocarbons and to develop proven hydrocarbon reserves. However, the subject of subsurface mapping is probably the least discussed in Abu Dhabi, yet most important, aspect of petroleum exploration and development. This paper presents the tectonic map for Abu Dhabi based on gravity, magnetic and seismic interpretations, along with describing the various elements, their controlling faults and their effect on basin development and also rationalizes previously published structural and tectonic elements to clarify the kinematic relations and naming of individual tectonic elements. The method, which combines geologic, geophysical data in a comprehensive way, incorporates these data to simulate the interrelated effects of deposition and erosion of sediments and compaction, pressure, petroleum generation and multiphase fluid flow. The tectonic map of Abu Dhabi distinguishes three principal tectonic cycles: (1) Precambrian cycles are interpreted using the magnetic data, as there are no wells that penetrated the basement in Abu Dhabi and the seismic is mostly covering up to Jurassic layers. (2) The Paleozoic cycle began with continental rifting about 550 Ma, followed by inundation of much of Abu Dhabi by shallow seas. This cycle ended with the opening of the Neo-Tethys, which caused the deposition of the Mesozoic Cycle. (3) The Mesozoic cycle represents the legacy of ocean opening and the rise and fall of sea level created the stratigraphic and structural features that would later trap vast quantities of oil and gas. On the tectonic map, major features record this history. Abu Dhabi is affected by at least seven major tectonic events, which are shaping the present structures. However, these events can be complicated by the salt-movements (halokinesis) in offshore areas of Abu Dhabi, which resulted in change of structural relief and faults/fracture characterization particularly for deep reservoirs. Understanding of the kinematics and mechanics of the structures will highly impact the preservation of most of the hydrocarbons, and in turn reveals the new ventures to add reserves for Abu Dhabi.