Research on Diagenetic Facies Based on Diagenetic Effect in the Low Permeability Sandstone Reservoir - A Case from C8₁ Reservoir in Huanjiang Region, Ordos Basin

Abstract

The research is carried out on diagenetic minerals, pore types and its impact on the physical properties in Huanjiang C81reservoir of Ordos basin, which is based on reservoir physical property test, thin sections observation and scanning electron microscopy. Several minerals closely associated with reservoir physical properties are identified from diagenetic effect views. It results in that a classification is proposed for the diagenetic facies, consisting of four kinds of diagenetic facies: ferroan calcite cementation facies, hydromica/kaolinite cementation facies, chlorite coating facies and feldspar dissolution facies. The study of C81reservoir in Huanjiang region shows that this scheme is favorable to estimate low permeability reservoir, the result shows fairly good consistency with the distribution of physical property of wells.

Diagenetic facies and reservoir porosity evaluation of deep high-quality clastic reservoirs: A case study of the Paleogene Shahejie Formation, Nanpu Sag, Bohai Bay Basin, China

“…A diagenetic facies is the synthesis of a diagenetic environment, diagenetic products and the material manifestation of a diagenetic environment (Liu et al, 2015;Mou and Brenner, 1982;Wang et al, 2014Wang et al, , 2017. According to the analysis of diagenesis intensity, castingthin-section and SEM data, the deep reservoirs in the study area are divided into five typical diagenetic facies: (1) strongly compacted-weakly cemented-weakly dissolved facies (Diagenetic Facies A); (2) weakly compacted-strongly cemented-weakly dissolved facies (Diagenetic Facies B); (3) moderately compacted-moderately cemented-weakly dissolved facies (Diagenetic Facies C); (4) strongly compacted-weakly cemented-moderately dissolved facies (Diagenetic Facies D); (5) strongly compacted-weakly cemented-strongly dissolved facies (Diagenetic Facies E) (Table 1).…”