Seismic Reservoir Characterization of the Low Porosity and Permeability Reservoir

Abstract

Seismic reservoir characterization is applied at a low porosity and permeability sandstone oil field, which has over 20 years of development and production history, located at the outside of Daqing Oilfield, China. This field was discovered in 1980s, developed and produced in 1993 by using an inverted nine spot method with 300 by 300m well network. The hydrocarbon reservoir is characterized to the fine-grained sandstone and silty sandstone which the porosity and permeability are 16.9% and 10.5mD, respectively. The reservoir thickness along wellbole is 0.5 – 15 m which the 90% of reservoir thickness is less than 5 meter in this field. There are very complicated distribution of the sand bodies and high heterogeneity of the reservoir in the field. Currently, the key challenge in this field is to find the residual and/or potential oil zones, so that it is necessary to carry out the fine reservoir characterization. This paper presents a case study of fine reservoir characterization in a low porosity and permeability sandstone reservoir by using geostatistical inversion outside of the Daqing oilfield. By using seismic reservoir characterization of geostatstical inversion with well constraint, the characterization result of the low porosity and permeability reservoir in the study area has been proved to be more reliable, and the spatial heterogeneity of the sand and/or reservoir is better described.