Investigating the Impress of the Active Tectonics and the Rate of Fractures in Ilam Formation, Fars Area, SW Iran

Reza Poursoltani,Mohsen Pourkermani,Mahmood Almassian,Koros Yazdjerdi

doi:10.4236/ojg.2016.66041

Abstract

The evolution of the Active Tectonics of the Ilam Formation (Santonin) form potential reservoir rocks at oilfields and structures in costal fars. Core and cuttings samples and wire-line logs from wells in the East Gardan field were used to investigate microfacies types and porosity evolution. Facies modelling was applied to predict the relationship between facies distribution and reservoir characteristics to construct a predictive geologic model which will assist future exploration in East Gardan field. Microfacies analysis and electrofacies identification and correlations indicate that the limestones of the Ilam Formation were deposited in a ramp setting. The ramp developed over the distal margin of the Santonin proforeland basin, adjacent to the evolved forebulge. Inner ramp facies are characterized by carbonate bank bioclastic packstones. Middle ramp facies dominate the Ilam Formation and consist of bioturbated, massive, dolomitic and bioclastic limestones. Bioclasts include benthic and planktonic foraminifera. Intense less common Palaeophycus bioturbation has enhanced the porosity of this facies. Outer ramp deposits consist of alternating mid-ramp bioturbated bioclastic massive limestones and argillaceous and marly limestones. Bioclastic packstones and intensively bioturbated bioclastic limestones of the mid-outer ramp are the primary source of fabric-selective porosity which is greatly enhanced by diagenetic overprints.

Highlights

The associated foreland basin represents one of the oldest and richest hydrocarbon provinces known [1]
In Fars, both reactivation of basement faults and/or Zagros deformation controlled the evolution of the foreland basin between the Late Cretaceous Below, we discuss the isopach maps compiled in order to study the effect of these two elements on foreland basin evolution. 3.1
The Influence of the Zagros Orogeny on Foreland Basin Evolution Foreland basins are generally accepted to express downward flexure of the lithosphere in front of a tectonic load imposed by the advancing thrust sheets [25] [26]

Summary

Introduction

The associated foreland basin represents one of the oldest and richest hydrocarbon provinces known [1]. (2016) Investigating the Impress of the Active Tectonics and the Rate of Fractures in Ilam Formation, Fars Area, SW Iran. The Zagros Main Thrust and accompanying ophiolites form the northern margin of the belt and separate it from the Central Iran block. The Fars area has a long history of hydrocarbon exploration and production but relatively few wells drilled here have been successful. Both high quality source rocks and regional seals are present and carbonates in the Santonian Ilam Formation form a major reservoir unit permeability varies significantly due to variations in depositional facies and diagenesis

Methods

Results

Conclusion