Energy Geoscience (Apr 2022)
Quality evaluation of glutenite reservoirs of intergranular - secondary dissolution pore type using a quantitative method
Abstract
Glutenite (coarse-grained clastic) reservoirs of intergranular–secondary dissolution pore type are dominated by residual intergranular pores and secondary dissolution pores, and characterized by low porosity, low permeability, strong heterogeneity, and highly variable physical properties. It is difficult to conduct a quantitative quality assessment of these reservoirs while their primary control factors remain unclear. In this paper, experimental core data and drilling, logging and seismic data are used to assess the effect of sedimentary facies on reservoir quality. Favorable sedimentary facies zones are identified by analyzing the characteristics of glutenite reservoirs, which includes investigating rock components and their effects on reservoir quality. Argillaceous matrix content and rigid particle content are identified as the primary control factors for these reservoirs. Logging curves sensitive to reservoir quality are selected and examined to continuously characterize the physical parameters of the reservoirs. It establishes a calculation model of reservoir assessment parameters through multivariate regression and determines the quantitative assessment parameter Fr. The quality of the glutenite reservoirs is defined using conventional logging curves. This study also predicts the plane distribution of high-quality reservoirs through geostatistical inversion of the reservoir assessment parameters based on conventional wave impedance inversion, thus providing insight and guidance for quantitative assessment and quality prediction of glutenite reservoirs of the intergranular-secondary dissolution pore type. The application of this method to well deployment based on qualitative evaluation of the glutenite reservoirs in oilfields yielded favorable results.
