Quantitative characterization of micropore structure for organic-rich Lower Silurian shale in the Upper Yangtze Platform, South China: Implications for shale gas adsorption capacity
Journal Title: Advances in Geo-Energy Research - Year 2017, Vol 1, Issue 2
Abstract
The pores in shales are mainly of nanometer-scale, and their pore size distribution is very important for shale gas storage and adsorption capacity, especially micropores having widths less than 2 nm, which contribute to the main occurrence space for gas adsorption. This study is focused on the organic-rich Lower Silurian black shale from four wells in the Upper Yangtze Platform, and their total organic carbon (TOC), mineralogical composition and micropore characterization were investigated. Low pressure CO2 adsorption measurement was conducted at 273.15 K in the relative pressure range of 0.0001-0.03, and the micropore structure was characterized by Dubinin-Radushkevich (DR) equation and density functional theory (DFT) method and then the relationship between micropore structure and shale gas adsorption capacity was discussed. The results indicated that (1) The Lower Silurian shale have high TOC content in the range of 0.92-4.96%, high quartz content in the range of 30.6-69.5%, and high clays content in the range of 24.1-51.2%. The TOC content shows a strong positive relationship with the quartz content which suggests that the quartz is mainly biogenic in origin. (2) The micropore volume varies from 0.12 cm3/100 g to 0.44 cm3/100 g and micropore surface area varies from 4.97 m2/g to 17.94 m2/g. Both of them increase with increasing TOC content, indicating TOC is the key factor to control the micropore structure of the Lower Silurian shale. (3) Low pressure CO2 adsorption measurement provides the most suitable detection range (0.3-1.5 nm) and has high reliability and accuracy for micropore structure characterization. (4) The TOC content is the key factor to control gas adsorption capacity of the Lower Silurian shale in the Upper Yangtze Platform.
Authors and Affiliations
Lei Chen, Zhenxue Jiang, Keyu Liu, Fenglin Gao
Review on Dynamic Van der Waals Theory in two-phase flow
In this paper we review the Dynamic Van der Waals theory, which is a recent developed method to study phase separation and transition process in multiphase flow. Gradient contributions are included in the entropy and ene...
Estimation of minimum miscibility pressure of varied gas compositions and reservoir crude oil over a wide range of conditions using an artificial neural network model
Minimum miscibility pressure (MMP) is a key variable for monitoring miscibility between reservoir fluid and injection gas. Experimental and non-experimental methods are used to estimate MMP. Available miscibility correla...
A new model for calculating permeability of natural fractures in dual-porosity reservoir
During the development of naturally fractured carbonate reservoirs, understanding the change in fracture permeability is the basis for production evaluation and scientific development. The conventional method of analyzin...
Using proper orthogonal decomposition to solve heat transfer process in a flat tube bank fin heat exchanger
Proper orthogonal decomposition (POD) reduced-order model can save computing time by reducing the dimension of physical problems and reconstructing physical fields. It is especially suitable for large-scale complex probl...
Influence of permeability anisotropy on heat transfer and permeability evolution in geothermal reservoir
Extracting heat energy from geothermal reservoirs essentially relies on circulating cold fluid within fractured hot rocks. The intrinsic anisotropic permeability in the reservoir directly affects the path of flow and the...