Microfacies Analysisand diagenesis process of Hartha Formation East Baghdad oilfield, center Iraq

Abstract

This study focused on interpreting the carbonate microfacies of Hartha Formation and the impact of diagenesis processes in selected wells of East Baghdad oil field. A total of 33 thin sections were examined from cutting and core samples. The study revealed distinct microfacies indicating different paleoenvironments. The outer-ramp environment is characterized by mudstone and wackestone microfacies dominated by planktonic foraminifera. Mid-ramp environment is distinguished by lime mudstone, bioclastic wackestone and foraminiferal-bioclastic wackestone. The inner ramp environment is subdivided into shoal, open marine, and restricted subenvironments. The shoal environment is only identified by rudistid grainstone microfacies. The open marine environment includes Benthic foraminifreal wackestone and Foraminiferal-echinoderm packstone. Restricted marine environment consists of mud-support microfacies such as Benthic foraminiferal-bioclastic wackestone and Rotalidwackestone Diagenetic processes affect the textural properties of Hartha Formation microfacies. They include dolomitization, cementation, compaction, and fracturing.