The effect of thermal maturity on geomechanical properties in shale reservoirs: An example from the Upper Devonian Duvernay Formation, Western Canada Sedimentary Basin

The Influence of Reservoir Composition on the Pore Structure of Continental Shale: A Case Study from the Qingshankou Formation in the Sanzhao Sag of Northern Songliao Basin, NE China

“…In this study, a threshold value of R 2 > 0:2 was set to characterize the strength of the correlation. The N 2 GA mainly characterized the pore structure in the range of the nanoscale pore size, and the MICP mainly characterized the pore structure of the micron pore size [23]. Therefore, the nitrogen adsorption experiment results were used for the pore volume analyzed with a pore diameter less than 100 nm, and the high-pressure mercury injection experiment results were used for the pore volume analyzed with pore diameter larger than 100 nm in this study 13 Geofluids (Table 4).…”

“…Therefore, the nitrogen adsorption experiment results were used for the pore volume analyzed with a pore diameter less than 100 nm, and the high-pressure mercury injection experiment results were used for the pore volume analyzed with pore diameter larger than 100 nm in this study 13 Geofluids (Table 4). Quartz is a typical rigid mineral with stable properties, high hardness, and compaction resistance, so the existence of quartz can protect the rock skeleton [23]. There is a positive correlation coefficient of 0.417 between quartz content and porosity.…”

“…At the same time, S 1 is positively correlated with TOC (Figure 11(d)), with the increase of the TOC content, the generated residual oil is mainly adsorbed on the surface of kerogen or filled in the mineral pores, blocking the pore space of shale, and the residual oil occupies the surface area of shale, making the pore space and total pore volume decreased. Therefore, the TOC content has a strong control on the development of organic matter pores [23,38].…”

“…Mineral composition and organic matter characteristics are the main controlling factors for the physical properties and pore structure of shale. The mineral composition of organic rich shale is strongly heterogeneous, for example, Longmaxi Formation, Marcllus, Barnett, and Haynesville shale are mainly composed of clay minerals and quartz [22], while Shahejie Formation in Liaohe Sag, Green River shale, Eagle Ford shale, and Niobrara shale consist of carbonate with a small amount of quartz, feldspar, and clay minerals [8,12,17,23,24]. The mineral composition can reflect the sedimentary environment, and brittle minerals are of great significance to the development of fractures [25].…”

“…The mineral composition can reflect the sedimentary environment, and brittle minerals are of great significance to the development of fractures [25]. Quartz exists in the shale by the form of continental, biogenic, authigenic, secondary enlarged, and microcrystal-line types [23,26]. In the process of hydrocarbon generation, the decarboxylation of organic matter generates CO 2 , which combines with H 2 S to form carbonic acid, phenolic acid, and so on [22].…”