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Transcript of SULFATE REDUCING BACTERIA, NITRATE REDUCING BACTERIA SULFATE REDUCING BACTERIA, NITRATE REDUCING...

  • SULFATE REDUCING BACTERIA, NITRATE

    REDUCING BACTERIA AND THEIR INTERACTIONS

    IN A SOURING OFFSHORE OIL RESERVOIR SYSTEM

    By

    © Fuqiang Fan

    A thesis submitted to the School of Graduate Studies

    in partial fulfillment of the requirements for the

    Degree of Doctor of Philosophy

    Faculty of Engineering of Applied Science

    Memorial University of Newfoundland

    October, 2018

    St. John’s Newfoundland and Labrador Canada

  • I

    ABSTRACT

    The troublesome souring issues, especially those occurred in offshore oilfields, have plagued

    petroleum and environmental industries for decades. To control reservoir souring, the nitrate

    addition have been noticed in recognition of their safety and operational effectiveness. The

    interactions between sulfate reducing bacteria (SRB) and nitrate reducing bacteria (NRB) are key

    mechanisms in the nitrate-mediated souring control. However, much is still unknown towards the

    effective profiling of SRB and the detailed NRB-SRB interactions. Although NRB produced

    biosurfactants might be promising bio-agents affecting NRB-SRB interactions, very limited

    studies tackled the production of biosurfactants by natural NRB strains. Systematic investigation

    of their unique roles in enhancing NRB competence over SRB was not documented. This thesis

    targeted on filling the above stated gaps and examined SRB, NRB and their interactions in a

    souring offshore oil reservoir system.

    A method based on phospholipid fatty acid (PLFA) profiling of microbial communities in

    offshore produced water was developed and optimized. The developed method was further

    applied to profile microorganisms and trace SRB. Biosurfactant producing NRB was isolated and

    the associated biosurfactant product was used for tracking NRB-SRB-biosurfactant interactions.

    The outputs of this thesis include: (1) the established PLFA based protocol for profiling SRB in

    offshore reservoirs; (2) the successful isolation and identification of biosurfactant producing

    NRB coupled with subsequent biosurfactant generation and characterization; and (3) the findings

    to confirm, for the first time, that NRB-produced biosurfactants could significantly strengthen

    SRB inhibition by NRB. The thesis has resulted in promising products and scientific

    observations for aiding souring control in the challenging offshore reservoir environments.

  • II

    ACKNOWLEDGMENT

    First and foremost, I would like to express my deep sense of gratitude to my supervisor, Dr.

    Baiyu (Helen) Zhang. I am indebted for her excellent supervision, constructive criticism,

    extensive encouragement and invaluable guidance throughout the course of my research degree.

    I also highly appreciate Dr. Penny L. Morrill and Dr. Tahir Husain for serving in the supervisory

    committee and spending time on reviewing my work. Dr. Penny L. Morrill has provided me with

    constant support, encouragement, and guidance while Dr. Tahir Husain has inspired and supported

    me with his practical advice and graceful patience. Special thanks to Dr. Bing Chen for his

    generous guidance with his expertise, experience and encouragement.

    I gratefully acknowledge the Faculty of Engineering and Applied Science, School of Graduate

    Studies at the Memorial University of Newfoundland (MUN), and Suncor Energy Inc. for

    financial support. My sincere thanks also go to Lidan Tao, Brettney Pilgrim, Jamie Warren, Linda

    Winsor, Jeanette Wells, and Christopher Deacon for their assistance to the physicochemical and

    genomic analysis. My further appreciation goes to my colleagues Dr. Jisi Zheng, Dr. Bo Liu,

    Qinhong Cai, Jiabin Liu, Weiyun Lin, Zhiwen Zhu, Jingjing Ling, Xing Song, Xixi Li, Samira

    Narimannezhad and Dr. Yinchen Ma for their friendship, valuable collaboration and assistance.

    Special thanks are given to Adam Taylor and Shawn Beson for their kind assistance in the lab.

    Finally, I wish to express my special appreciation to my parents and my siblings for their selfless

    love and continued support which are the true source of inspiration in my pursuit of doctorate

    degree. The deepest thanks are expressed to my girlfriend Tianjun Tan, for her remote but

    endless love, enormous support and unlimited patience on the other side of the Earth.

    https://www.google.com/url?q=http://www.mun.ca/ogdp/emba_archive/husain.php&sa=U&ved=0ahUKEwjCn6LH1qnSAhXmDcAKHfHcBQ8QFggKMAI&client=internal-uds-cse&usg=AFQjCNEuFOaQViCyL_OCjx4YfrJ1wh2GHg https://www.google.com/url?q=http://www.mun.ca/ogdp/emba_archive/husain.php&sa=U&ved=0ahUKEwjCn6LH1qnSAhXmDcAKHfHcBQ8QFggKMAI&client=internal-uds-cse&usg=AFQjCNEuFOaQViCyL_OCjx4YfrJ1wh2GHg https://www.facebook.com/samira.corleone.9?ref=br_rs https://www.facebook.com/samira.corleone.9?ref=br_rs

  • III

    TABLE OF CONTENTS

    ABSTRACT……………………………………………………………………………………….I

    ACKNOWLEDGMENT................................................................................................................. II

    TABLE OF CONTENTS .............................................................................................................. III

    LIST OF FIGURES ................................................................................................................... VIII

    LIST OF TABLES ....................................................................................................................... XII

    LIST OF SYMBOLS AND ABBREVIATIONS ...................................................................... XIII

    CHAPTER 1 INTRODUCTION ................................................................................................... 1

    1.1 Background ........................................................................................................................... 2

    1.2 Statement of Problems .......................................................................................................... 8

    1.3 Research Objectives ............................................................................................................ 11

    1.4 Structure of the Thesis ........................................................................................................ 12

    CHAPTER 2 LITERATURE REVIEW ...................................................................................... 14

    2.1 Mechanisms of Offshore Reservoir Souring....................................................................... 15

    2.1.1 Routes of H2S generation in offshore reservoirs.......................................................... 15

    2.1.2 Roles of SRB in offshore reservoir souring ................................................................. 19

    2.2 Microbial Monitoring of Offshore Reservoir Souring ........................................................ 20

    2.2.1 Microbial characterization methodologies ................................................................... 21

  • IV

    2.2.2 PLFA with FAME quantification ................................................................................ 26

    2.3 Offshore Reservoir Souring Control ................................................................................... 31

    2.3.1 Popular control techniques ........................................................................................... 31

    2.3.2 Nitrate/Nitrite injection ................................................................................................ 35

    2.4 Biosurfactants and Reservoir Souring Control ................................................................... 41

    2.4.1 Introduction of biosurfactants ...................................................................................... 41

    2.4.2 Biosurfactant producers in reservoirs .......................................................................... 55

    2.4.3 Anti-souring effects of biosurfactants .......................................................................... 57

    2.5 Summary ............................................................................................................................. 64

    CHAPTER 3 PLFA ANALYSIS FOR PROFILING MICROBIAL COMMUNITIES IN

    OFFSHORE PRODUCED WATER ............................................................................................ 71

    3.1 Background ......................................................................................................................... 72

    3.2 Materials and Methods ........................................................................................................ 76

    3.2.1 Chemicals, reagents and glassware .............................................................................. 76

    3.2.2 Sample collection ......................................................................................................... 77

    3.2.3 Extraction of lipids from water samples ...................................................................... 77

    3.2.4 SPE optimization ......................................................................................................... 78

    3.2.5 Derivatization of FAME optimization ..........