Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Lynch, F. Leo

Committee Member

Mylroie, John E.

Committee Member

Brown, Lewis R.

Committee Member

Kirkland, Brenda L.

Date of Degree

8-3-2002

Document Type

Graduate Thesis - Open Access

Major

Geosciences

Degree Name

Master of Science

College

College of Arts and Sciences

Department

Department of Geosciences

Abstract

This study uses scanning electron microscopy (SEM) to examine the occurrence of bacteria and their exopolysaccharide slime layer in microbial enhanced oil recovery experiments. A test of SEM preservation techniques showed that air drying and 10% glutaraldehyde fixation preserved the slime layer but distorted and flattened bacteria. Techniques with ethanol dehydration preserved the bacterial textures but fragmented the slime layer. In sandstones that had been plugged during microbial enhanced oil recovery experiments, bacteria are sparsely distributed. An irregular, confluent slime sheet covers grains and coats pore spaces and is responsible for permeability modification in microbial enhanced oil recovery. The development of the slime layer over time involves several steps: growth of ultramicrobacteria into full-sized bacteria; creation of a slime capsule; growth of globular masses, ropy masses, webs, thin sheets; and growth of a thicker, poreilling mass of slime associated with large balls of slime.

URI

https://hdl.handle.net/11668/20247

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