Control of microbial sulfide production by limiting sulfate dispersal in a water-injected oil field.

Oil production by water injection often involves the use of makeup water to replace produced oil. Sulfate in makeup water is reduced by sulfate-reducing bacteria to sulfide, a process referred to as souring. In the MHGC field souring was caused by using makeup water with 4mM (384ppm) sulfate. Mixing with sulfate-free produced water gave injection water with 0.8mM sulfate. This was amended with nitrate to limit souring and was then distributed fieldwide. The start-up of an enhanced-oil-recovery pilot caused all sulfate-containing makeup water to be used for dissolution of polymer, which was then injected into a limited region of the field. Produced water from this pilot contained 10% of the injected sulfate concentration as sulfide, but was free of sulfate. Its use as makeup water in the main water plant of the field caused injection water sulfate to drop to zero. This in turn strongly decreased produced sulfide concentrations throughout the field and allowed a decreased injection of nitrate. The decreased injection of sulfate and nitrate caused major changes in the microbial community of produced waters. Limiting sulfate dispersal into a reservoir, which acts as a sulfate-removing biofilter, is thus a powerful method to decrease souring.

In vivo and in vitro production and detection of monoclonal antibodies to surface components on metastatic variants of murine tumor cells.

Mouse-mouse and rat-mouse hybridoma cell lines secreting complement-dependent cytotoxic or cell-binding monoclonal antibodies have been produced against cell surface components of two murine metastatic tumor systems: B16 melanoma and RAW117 lymphosarcoma. We have used both in vivo and in vitro spleen cell culture methods for immunization and have made a number of methodologic alterations to increase the yield and survival of hybridomas including media osmolality, pH, serum type, macrophage feeder layers and supplemented amino acids, vitamins and metabolites. Using complement-dependent cytotoxicity or lectin immobilization of tumor cells to polystyrene via a water-soluble carbodiimide for an enzyme-linked immunosorbant assay we were able to rapidly screen hybridoma cultures for specific antibody secretion.