This study was prepared as part of a preliminary research program to study the effect of bacteria on the specifications of petrophysical models for reservoir rock -contrast-General in its porous reservoir permeability of the AL-Atta main/south Rumaila fluid. The technique was used permeability for the passage of fluid KL in the evaluation of the accounts permeability of a typical section diameter (1.5 inches) in this study, contrast between them in permeability and porosity, prepared charts and graphs (figures) in particular include the effect of bacterial on the permeability when injected liquid plus bacteria were calculated permeability of the rock for the passage of fluid First, the traditional way and then calculated the permeability for the passage of fluid inoculated with bacteria and the extent of change in the permeability for comparison purposes. To know how much this vulnerability isolated for this study three types of bacteria depending on their need for oxygen to produce energy used for effective bio-growth, reproduction and that gets my way, the redox, and the statement of the different effects of these species and types of vulnerability that could get the rocks of different permeability and identify the problem non-knowledge or non-diagnostic and the amount of impairment laboratory as a basis for opening a new science devoted to the importance of what caused microbiology damage and can be used in aspects of benefit in the field of oil production and minimize material losses due to this type of pollution produced by these microorganisms and to find ways to protect the oil fields of this serious problem. The findings of this study to the major axis are the effect of specific types of microorganisms on the rocks, the reservoir of permeability high, medium and thus lower the rate of oil production and this, in turn, leads to economic return is bad, which can be treated in ways that modern art advanced and modern methods in Part II of the study to achieve better ways to extract oil from oil wells by treating affected.