RESERVOIR CONDITION EXPERIMENTAL STUDY TO INVESTIGATE MICROBIAL ENHANCED OIL RECOVERY(MEOR) IN THE DEEP RESERVOIR ENVIRONMENT

摘要

This paper describes an experimental study,comprising a series of reservoir condition core floods,which when combined with appropriate up-scaling simulation allow the determination of microbial enhanced recovery(MEOR) in an oil reservoir. The experimental methods described combine both single and novel dual core flood techniques to generate data applicable to the deep reservoir environment,thus enabling an improved prediction of Microbial Enhanced Oil Recovery. Initial studies(not covered by this paper) at both ambient and reservoir conditions,used conventional single core floods to demonstrate that MEOR could provide additional oil production.The potential for bio-diversion of flow was also demonstrated.However,the single core flood experimental design was such that results may have only been applicable to the near well-bore region in an actual reservoir. The result of a new study to investigate MEOR using a dual core propagation technique is described.Advanced reservoir condition core flooding hardware,procedures and insitu gamma attenuation saturation measurement techniques have been modified to enable the propagation of microbial behaviour to be investigated. Two cores,at full reservoir conditions,were connected in series such that the effluent from the first core(representing the near well-bore region and inoculated with microbes) was injected directly into the second core(representing the deeper reservoir environment and not inoculated).The successful demonstration of propagation of the MEOR effect was through additional oil production from the second core when compared to previous baseline control floods.The intention of this paper is to describe the novel reservoir condition dual-core laboratory technique developed and to present qualitative results for one study The experimental data from all these experimental studies has been input into a detailed simulation study to upscale the results and enable field MEOR performance to be predicted.This study showed that propagation of the interfacially active microbe can produce additional oil in the deep reservoir environment.There is also strong indication from the core flood and using an associated NMR analysis that the propagated region showed a change in wettability towards a more water-wet state.