MEOR, Recent Field Trials in Romania: Reservoir Selection, Type of Inoculum, Protocol for Well Treatment and Line Monitoring

Abstract From 1975 to 1980, the first generation of MEOR field trials were carried out in Romania, based on microbial flooding recovery technology and using the level of technology of that time, with its pioneering deficiencies. The results were promising, but after 1980, it became apparent that many aspects of the MEOR technology we used should be improved, because a miracle is not possible with very simple MEOR technologies. This was the reason why, between 1980–1986, we prepared a “second generation” of MEOR field trials which took place between 1987–1991. Compared with the first generation of field trials, in this second generation we tried to improve the methods in the following ways: 1. enhancing the performance of the bacterial inoculum; 2. testing the inoculum for the production of substances involved in oil release; 3. with mathematical models, simulating the release of residual oil; 4. formulating a protocol for injecting the wells; 5. ensuring that adequate quantities of inoculum were used; and, 6. controlling nutrients and the time of their administration. In this paper we discuss the results obtained from 1987–1991 at the two reservoirs where cyclic microbial recovery and microbial flooding recovery trials were carried out. The possibilities of extending and improving these technologies at other reservoirs also are discussed.