Enhanced oil recovery from UAE limestone reservoirs using bacteria flooding,an experimental approach

摘要

This project investigates the use of bacteria,which is a minor cost material,to improve the oil recovery from UAE limestone rservoirs.The work focused initialy on the study of the interfacial tension (IFT) betwen crudes from four different UAE reservoirs and a therophilic microbial solution.The bacteria were obtained from local water taks.The system temperature was varied between 30-100degC and salinity ranged from 0 to 100,000 ppm.Bacteria solution tertiary core floodingexperimnets were then performed using carbonate rocks at reservoir conditions without injection f nutrient with the bacteria during the core flooding experiments.A good amount of effort was directed,throughout the wrok,to characterize the bacteria use dand identify the mechanism by which bacteria work to improve the oil recovery. Results of these laboratory studies showed an abrupt reductionin IFT at high saliity and high temperature for all studied systems expcept for the St crude,which was sulfur rich.The IFT decreased from 40 to 0.07 dyn/cm for most of the studied systems.Also,tertiary bacteria flooding at reservoir conditions,on average,resulted in an incremental oil recovery of 15 to 20% of thepore volume.