1997 Volume 62 Issue 3 Pages 195-202
In this paper, firstly, the establishment of quantitative evaluation techniques of capabilities of anaerobes in improving oil recovery is discussed, and then results of flooding experiments based on the techniques are presented.
Strain 9A, which was recognized as one of useful anaerobes through the studies reported in previous papers, was incubated in porous media to investigate effects of kerosine on its growth. As a result, the cultivation showed that kerosine itself had no influence upon the microbial multiplication and metabolism.
The flooding apparatus includes the sandpack which was comprised of an acrylic pipe packed with silica sands, injection pump and pressure measurement tools. The evaluation method was specified in this paper as follows; (1) making a sandpack, (2) measurement of water permeability, (3) saturating oil into the sandpack, (4) water flooding, (5) injecting microbes into the sandpack, (6) cultivation, and (7) recovering additional oil by injecting water. Regarding the microbial injection specified above at 5th clause, the minimum amount of liquid medium with microbes for uniform injection was decided through the investigation. Filteration of microbes did not occur.
Then flooding experiments based on the above method were carried out using 9 kinds of anaerobes. Consequently, the oil recovery was improved at all cases. Especially, the maximum oil recovery obtained with strain 9A amounted to 30% of residual oil.
