Laboratory Evaluation of Biosurfactant Solution for Filter Cake Removal to Enhance a More Wetness Condition in Oil Recovery (Published)
In order to regain wellbore permeability, several operators use synthetic surfactant, polymers and other chemical compounds to ensure interfacial tension reduction between oil-water/brine, mobility control, alteration of the wettability of the reservoir rocks, filter cake removal in wellbore cleanup and reservoir remediation operations. These synthetic surfactants are not biodegradable, they are expensive, toxic and are linked to products of petroleum origin. This accounts for the growing research interests in biosurfactants, environmentally friendly and cost effective remediation products of good compatibility with reservoir rocks, biodegradability and lower toxicity. A nonionic saponin extracts from indigenous plants were used to design a biosurfactant solution with mostly acid and solvent soluble materials. Formulation of reservoir drill-in fluid (RDIF) was carried out for the purpose of filter cake generation, using the American Petroleum Institute (API) high temperature/high pressure (HTHP) filter press. Appropriate evaluations and laboratory testing to determine the effectiveness and feasibility of the biosurfactant solution to remove the filter cake were carried out. Results showed that the biosurfactant solution formed was able to fluidize and remove the filter cake. It was able to solubilize the oil in the emulsion, leaving the solids and surfaces in a more water wet state to enhance injectivity and productivity in the reservoir.
Keywords: Biosurfactants, Remediation, biodegradability, nonionic, wettability
ISOLATION AND SCREENING OF BIOSURFACTANT- PRODUCING BACTERIA FROM SOIL CONTAMINATED WITH DOMESTIC WASTE WATER. (Published)
Bacterial isolates from waste water oil-contaminated soil sample were screened and evaluated for biosurfactant production in this study. Using culture –dependent technique, twenty two (22) bacterial isolates were recovered from eight (8) different sites. The dominant species were Bacillus and Pseudomonas; with an occurrence rate of 22.73% each. The isolates were subjected to conventional biosurfactant screening tests: qualitatively (drop collapse and microplate assay) and quantitatively (oil speading and emulsification activity). In all, Bacillus and Pseudomonas species were positive for all the tests and they had a clearing zone of 4mm each and an emulsification capacity of 51.61% and 53.13% respectively. This confirms their ability to produce biosurfactants that reduce interfacial and surface tension thereby leading to increase in solubility and emulsification of these oils.
Keywords: Biosurfactants, Index Emulsification Test, Surface tension, drop collapse, oil waste water
