Effects of diagenesis on the geomechanical and petrophysical aspects of the Jurassic Bir El-Maghara and Masajid carbonates in Gebel El-Maghara, North Sinai, Egypt

In the present study, the Jurassic Bir El-Maghara and Masajid Formations in North Sinai are subjected to a detailed microfacies analysis to identify the effect of the diagenetic factors on their geomechanical and petrophysical properties. The Bir El-Maghara Formation consists of mudstone microfacies, whereas the Masajid Formation consists of foraminiferal and molluscan mudstone microfacies, oolitic grainstone microfacies, mudstone microfacies, and foraminiferal-algal sparitic mudstone microfacies. These microfacies were deposited in restricted platform conditions through the entire section with some oscillations into shelf lagoon conditions in the middle parts of the sequence. The porosity and bulk density of Masajid and Bir El-Maghara Formations are strongly correlated with their petrophysical and geomechanical properties. These correlation relationships can help estimate the geomechanical properties statistically in terms of the petrophysical parameters.