Constrained 3D Gravity Inversion for the Mesopotamia Basin - A Case Study

The present case study is describe a procedures for 3D constrain inversion for the Mesopotamia basin -Iraq. To resolve the non-uniqueness in inversion process, high constrain is used through applying priori available information from different source such us wells. Three depth surface were extracted from wells data and basement depth relief map extracted from magnetic data reduced to pole. The method briefly done by adding these four surfaces with deferent depths and ages as constraint to 3D gravity inversion. Those surfaces are assisted to increase the accuracy and reality of basement image and sedimentary covers that support the understanding the tectonic situation of the Mesopotamia. The procedure of work starting from collecting prior information (wells data, density, geological reports) and prepare the hypothetical surfaces. These constraint surface decrease the misfit in forward modeling, so the inversion step became more accuracy and less ambiguity. The basement depth is estimated using 3D gravity inversion of Mesopotamian basin is ranging from 6.5km to 13km. The result of 3D gravity inversion was three structural relief surfaces (Jurassic, Cretaceous and Tertiary) explain the depression direction where the thickness of layers increased to the eastern side. Two profiles was modeled 2D (Line1 and Line2) and excellent coincidences was shown with 3D inversion and this support the reality of the method. Many faults and closures have been extracted from interpreting the results and apple to follow the fault movement from the basement to the sedimentary cover through different ages.