Survey of Heterogeneity of Oil-gas Saturation of Reservoir Using Seismic Emission Waves SLEC Technology

Considered is application of passive seismic monitoring technology SLEC (Seismic Location of Emission Centers) to survey the heterogeneity of oil saturation of reservoir in one of the fields of Orenburg region (Volga-Ural area, Russia). Presented is a brief description of SLEC technology designed for surface-based passive monitoring of seismic emission of geological formations and estimation of characteristics of reservoirs, particularly, reservoir fluid saturation type. Among benefits of SLEC technology are its surface based observation system and the use of Slionkin Focusing Transformation algorithms allowing to focus SLEC locator to any points of a geological formation (within the range of a few kilometers), thus allowing distinguish between useful and interference sources of emission signals. Presented are results of long-term SLEC monitoring. A comparison of SLEC processing results – map of oil saturation index versus production data acquired in operating wells and well test data supports the reliability of SLEC-based maps of reservoir oil saturation heterogeneity. These heterogeneity maps can be used to improve the efficiency of oil production and for post-exploration of the field.