The effect of the variation in material composition on the heterogeneous pore structure of high-maturity shale of the Silurian Longmaxi formation in the southeastern Sichuan Basin, China

Composition and pore characteristics of black shales from the Ediacaran Lantian Formation in the Yangtze Block, South China

“…The range of EVRo values obtained from the Raman spectra analysis was slightly lower (3.97e4.12%). It is Han et al, 2013;Jiao et al, 2014;Liang et al, 2014;Tang et al, 2015;Tian et al, 2013Tian et al, , 2015Wang et al, 2014), and EVRo values higher than 4% have also been reported for Lower Cambrian shales from the Yangtze Block (Ma et al, 2015;Wang et al, 2015). The Lantian shales are thus an additional reference for the compositional and pore characteristics of ultrahigh maturity shales.…”

“…The XRD analysis in this work has indicated a generally high pyrite content, up to 19%, except in one siltstone sample with extremely low TOC content (0.18%, Table 1). Mineralogical studies have shown pyrite content with a range for the majority of samples from 1% to 9% for Neoproterozoic, Lower Cambrian and Lower Silurian marine shales from the Upper Yangtze Block (Cao et al, 2015;Hou et al, 2014;Jiao et al, 2014;Liang et al, 2014;Ma et al, 2015;Tang et al, 2015;Tian et al, 2013Tian et al, , 2015Wang et al, 2013Wang et al, , 2014Wu et al, 2014), and highly abundant pyrite (ca. 12%) was observed in only a few samples (Han et al, 2013;Tan et al, 2014a).…”

“…These are some of the most promising strata for shale gas exploration in China (Dong et al, 2014;Tan et al, 2014aTan et al, , 2014bZou et al, 2011). Stratigraphic studies have indicated that the black shales in the Ediacaran Doushantuo Formation were mainly deposited in deep-water slope and basin settings (Jiang et al, 2011;Zhu et al, 2007); however, unlike the Cambrian and Silurian shales Han et al, 2013;Jiao et al, 2014;Liang et al, 2014;Ma et al, 2015;Tang et al, 2015;Tian et al, 2013Tian et al, , 2015Wang et al, 2015), the Ediacaran shales have not been described in great detail (Tan et al, 2014a).…”

Vertical Heterogeneity of the Shale Reservoir in the Lower Silurian Longmaxi Formation: Analogy between the Southeastern and Northeastern Sichuan Basin, SW China

“…LSL shale has become the most favored target stratum for shale gas recovery in China. Recent investigations of the LSL shale in the southeastern and eastern Sichuan Basin area have probed the geochemical characteristics [10], pore development characteristics [11], and methane adsorption capacity [12]. However, few investigations have evaluated the shale gas potential in the northeastern Sichuan Basin.…”

Lateral Percolation and Its Effect on Shale Gas Accumulation on the Basis of Complex Tectonic Background

“…Gao and Hu [33] found that Barnett shale has low pore connectivity by conducting imbibition experiments. A number of previous researchers, Ji et al [34,35], Wang et al [36,37], Tang et al [38][39][40], and Chen et al [41], indicated that organic matter provided most of the connected pores and that the network consisting of interconnected organic pores, microcracks, and bedding plane provided the main percolation pathway of shale gas. The accumulation pattern was deduced in the comprehensive consideration of previous studies and the experimental results, as well as related tectonism (Figure 6).…”