Comparison of microbial community compositions of injection and production well samples in a long-term water-flooded petroleum reservoir.

Water flooding plays an important role in recovering oil from depleted petroleum reservoirs. Exactly how the microbial communities of production wells are affected by microorganisms introduced with injected water has previously not been adequately studied. Using denaturing gradient gel electrophoresis (DGGE) approach and 16S rRNA gene clone library analysis, the comparison of microbial communities is carried out between one injection water and two production waters collected from a working block of the water-flooded Gudao petroleum reservoir located in the Yellow River Delta.

[Application of PCR-dGGE in selective activation of stratal bacteria].

With the development of molecular biology, the research on microflora in the environment is accelerated and a new research method for oil reservoir microflora is provided. Based on the methods of PCR-DGGE, the change of the structure of dominant microbial population in selectiveactivation of stratal bacteria was studied. During activation, the change of samples' DGGE bandings under different pressure conditions (1 MPa and 10 MPa) was analyzed, the PCR alignment analysis of bacteria was studied, the dominant bacteria at different periods were explored, the phylogenetic tree of dominant DGGE banding sequence was build, and the groups of the main indigenous bacteria was also analyzed.