Abstract
The present paper describes the results of petroleum systems modeling of Amudarya basin, which includes Bukhara and Chardzhou structural steps. The main purpose of the study is assessment of the quality of available data for the basin modeling, the description of the elements of petroleum systems, the history of source rock maturation and possible hydrocarbon migration routes, and recommendations for the required data.
There are two main source rocks in the Amudarya basin of Lower-Middle Jurassic and Upper Jurassic age, which correspond to type III and type II kerogen, respectively. The main reservoirs are carbonate structures of Oxfordian age and clastic rocks of the Cretaceous age. Caprock is a salt-anhydrite formation of Tithonian age, which acts as reliable regional seal.
As the result of the study, 1D models of Bukhara and Chardzhou steps and a 2D model through Gazli and Shurtan fields, showing the transformation ratio of kerogen and hydrocarbon migration routes, were obtained. Modeling was performed on petroleum systems modeling software. The results were calibrated with temperature and vitrinite reflectance data, where possible. The ability of the model to predict accumulations in the existing fields was tested.
The main elements of petroleum systems have good quality and the basin may contain up to 1.1 to 1.4 TCM of undiscovered gas. The authors believe that the potential of the Amudarya basin has not been exhausted, and there is the need for extensive and detailed basin modeling studies to identify the most perspective areas for further exploration.