Evaluation of the Feasibility of Combining Carbon Dioxide Flooding Technologies with Microbial Enhanced Oil Recovery Technologies in Order to Sequester Carbon Dioxide, (Final Report)

摘要

The need for more energy as our population grows results in an increase in the amount of CO2 introduced into the atmosphere. The effect of this introduction is currently debated intensely as to the severity of the effect of this. The objective of this investigation was to determine if the production of more energy (i.e. petroleum) and the sequestration of CO2 could be coupled into one process. Carbon dioxide flooding is a well-established technique that introduces compressed CO2 into a subsurface oilbearing formation to aide in liquefying harder to extract petroleum and enhancing its mobility towards the production wells. Although some of the CO2 remains in the subsurface formation its chemical composition is of little value. Carbon dioxide can be metabolically reduced into other compounds that would result in the carbon staying in the formation for longer periods of times. Although all organisms have the ability to metabolically fix CO2 including humans, plants, and microorganisms, it is the latter that possess the potential to be of value to performing this ability in the subsurface. Microbially enhanced oil recovery (MEOR) techniques have been investigated and implemented by different groups. More specifically the one developed by Mississippi State University involved the stimulation of microorganisms indigenous to the formation through the introduction of life essential nutrients that are typically absent from this environment. Once stimulated by the addition of nitrogen and phosphorus the microbes begin to grow and plug that channel thereby forcing the sweep water into newer locations resulting in an increase in oil production. Since it is true that all living cells can fix CO2 and it is known that the addition of nutrients will stimulate subsurface microorganisms to begin to grow, it was believed that these two technologies could be coupled to enhance oil recovery and sequester CO2 into cellular material or byproducts. This study utilized microorganisms previously isolated from another DOE funded project that characterized the microbial communities of core samples taken from different oil wells. Since this project was completed over 12 years ago, the cultures had to be revitalized from their hibernation. Twenty plus cultures were successfully revitalized and evaluated for metabolic activities. Of these 22 cultures, 4 cultures showed a great deal of CO2 fixation ability with two of them producing a significant amount of CH4 while another produced an abundance of lipids. The results of this investigation demonstrated that it was scientifically possible for microbes indigenous to the subsurface to convert CO2 into important chemicals. In order to understand the cost of the process more experiments would be needed using actual or simulated core experiments to understand the amount of incremental oil that would be produced.