Pay Zone Distribution of CSR Field using the Climate Stratigraphic Approach

Abstract

The CSR field is one of the largest gas condensate field located in the Amu-Darya petroleum province. The studied basin situated in the central and eastern parts of Turkmenistan, western part of Uzbekistan, and in the north of Afghanistan and Iran. The main target is Callovian Oxford-carbonate deposits characterized by high heterogeneity and this fact greatly complicates the prediction of reservoir rocks distribution.The object of the study is to improve the methods of constructing a geological model of the CSR field based on the climate stratigraphic method and development of recommendations for gas stimulation depending on the lithofacies features of productive deposits.In order to achieve the intended purpose the following tasks were discussed:• Studying the sedimentation patterns in the Callovian-Oxfordian basin in the north-western part of the Chardjou tectonic stage; • Core analysis and lithofacies/petrotypes identification; • Well correlation based on the climate stratigraphic method; • Reservoir properties analysis of identified lithofacies, evaluation of their productivity; • Production logging (PLT) analysis; • Areal distribution prediction of various lithofacies/petrotypes.The research methodology is based on a climate stratigraphic approach which enables the calculation of the gamma ray and gamma-spectrometry spectral trends sensitive to the conditions of sedimentation.The deposition model of the Upper Jurassic productive deposits of the CSR field constructed according only to lithological and facies core analysis is lack of credibility due to the small amount of core material. The reliability increasing can be achieved through the use of the climate stratigraphic method in order to improve the understanding of the depositional environment in which pay zones were deposited as well as to predict the composition of the sediment facies.This work has allowed the prediction of the areal distribution of pay zones and significantly improves the accuracy of geological and simulation models that are the basis of efficiency for geological exploration and field development.