Experimental study on hydrocarbon generation and expulsion characteristics of shale with different source-reservoir structures in Lucaogou Formation, Jimsar Sag, Junggar Basin

The Permian Lucaogou Formation in the Jimusar Sag in the east of the Junggar Basin is a typical continental shale oil series in China. Employing the semi-closed thermal simulation system, an experimental study on hydrocarbon generation and expulsion of shale with different source-reservoir structures was carried out to explore the efficiency and composition characteristics of hydrocarbon generation and expulsion of shale in the Permian Lucaogou Formation with different source-reservoir structures so as to provide reference for the enrichment rule of shale hydrocarbon and the fine evaluation of "sweet spots". The experimental results show that thick reservoir interbedded with thin source rock is more conducive to hydrocarbon expulsion and features the highest hydrocarbon expulsion efficiency, while thin source rock interbedded with thin reservoir features slightly lower hydrocarbon expulsion efficiency, and thick source rock interbedded with thin reservoir features the lowest hydrocarbon expulsion efficiency. When reservoir lithology is clastic rock, the hydrocarbon expulsion efficiency of thick reservoir interbedded with thin source rock, thin source rock interbedded with thin reservoir, and thick source rock interbedded with thin reservoir are 35.6%, 30.7%, and 25.6%, respectively. When reservoir lithology is carbonate rock, the hydrocarbon expulsion efficiency of these three combinations are 27.4%, 27.5%, and 12.3%, respectively. Combined with composition of expelled hydrocarbon, received hydrocarbon in reservoir, and retained hydrocarbon in source rock, it is found that received hydrocarbon in reservoir rock is mainly supplied by neighboring sources, and the farther away from source-reservoir interface, the less relevant relationship between source rock and hydrocarbon in reservoir. Hydrocarbon in reservoir is supplied by lower adjacent source rock in thick reservoir interbedded with thin source rock, and the received hydrocarbon in upper clastic reservoir is 10.7 mg/g, while received hydrocarbon in lower clastic reservoir is only 1.4 mg/g. The thick source rock interbedded with thin reservoir is mainly self-generated and self-stored, and the content of retained hydrocarbon in source rock is high, the received hydrocarbon in upper clastic reservoir is 6.0 mg/g, while retained hydrocarbon in source rock is 21.1 mg/g. Hydrocarbon in reservoir is mainly supplied by lower adjacent source rock and partly from its own source rock in thin source rock interbedded with thin reservoir. There is no significant difference between source rock and reservoir rock in the extraction family, with the content of saturated hydrocarbon in the range of 22.8%-33.0%, aromatics in the range of 6.2%-15.1%, and non-hydrocarbon and asphaltene in the range of 28.5%-41.1% and 21.0%-30.0%. Moreover, different reservoir lithology has relatively weak influence on hydrocarbon generation and expulsion efficiency, and the hydrocarbon-bearing heterogeneity is weak in thin source rock interbedded with thin reservoir. From the perspective of hydrocarbon generation and expulsion efficiency of shale with different source-reservoir structures, thick reservoir interbedded with thin source rock and thin source rock interbedded with thin reservoir are the favorable combinations for hydrocarbon exploration in the shale of the Lucaogou Formation

High-Temperature Cracking of Pentene to Ethylene and Propylene over H-ZSM-5 Zeolites: Effect of Reaction Conditions and Mechanistic Insights

The effects of reaction conditions on the yield of ethylene and propylene from pentene cracking were investigated in a fixed-bed reactor at 500–750 °C and for a weight hourly space velocity (WHSV) of 15–83 h−1. The total yield of ethylene and propylene reached a maximum (67.8 wt%) at 700 °C and 57 h−1. In order to explore the reaction mechanism at high temperatures, a thermal/catalytic cracking proportion model was established. It was found that the proportion of pentene feed chemically adsorbed with the acid sites and cracked through catalytic cracking was above 88.4%, even at 750 °C. Ethylene and propylene in the products were mainly derived from catalytic cracking rather than thermal cracking at 650–750 °C. In addition, the suitable reaction network for pentene catalytic cracking was deduced and estimated. The results showed that the monomolecular cracking proportion increased from 1% at 500 °C to 95% at 750 °C. The high selectivity of ethylene and propylene at high temperatures was mainly due to the intensification of the monomolecular cracking reaction. After 20 times of regeneration, the acidity and pore structure of the zeolite had hardly changed, and the conversion of pentene remained above 80% at 650 °C

Fermented Myriophyllum aquaticum and Lactobacillus plantarum Affect the Distribution of Intestinal Microbial Communities and Metabolic Profile in Mice

This research explores the effects of fermented Myriophyllum aquaticum (F) and Lactobacillus plantarum BW2013 (G) as new feed additives on the gut microbiota composition and metabolic profile of mice. Crude protein (p = 0.045), lipid (p = 0.000), and ash (p = 0.006) contents in Myriophyllum aquaticum (N) were improved, whereas raw fiber (p = 0.031) content was decreased after solid-state fermentation by G. Mice were fed with no additive control (CK), 10%N (N), 10%N + G (NG), 10%F (F), and 10%F + G (FG). High-throughput sequencing results showed that, compared with the CK group, Parabacteroides goldsteinii was increased in treatment groups and that Lactobacillus delbrueckii, Bacteroides vulgatus, and Bacteroides coprocola were increased in the F and FG groups. Bacteroides vulgatus and Bacteroides coprocola were increased in the F group compared with the N group. Metabolomic results showed that vitamin A, myricetin, gallic acid, and luteolin were increased in the F group compared with the N group. Reduction in LPG 18:1 concentration in the N and F groups could be attenuated or even abolished by supplementation with G. Furthermore, 9-oxo-ODA was upregulated in the FG group compared with the F group. Collectively, N, F, and G have beneficial effects on gut microbiota and metabolic profile in mice, especially intake of FG

Fermented <i>Myriophyllum aquaticum</i> and <i>Lactobacillus plantarum</i> Affect the Distribution of Intestinal Microbial Communities and Metabolic Profile in Mice

This research explores the effects of fermented Myriophyllum aquaticum (F) and Lactobacillus plantarum BW2013 (G) as new feed additives on the gut microbiota composition and metabolic profile of mice. Crude protein (p = 0.045), lipid (p = 0.000), and ash (p = 0.006) contents in Myriophyllum aquaticum (N) were improved, whereas raw fiber (p = 0.031) content was decreased after solid-state fermentation by G. Mice were fed with no additive control (CK), 10%N (N), 10%N + G (NG), 10%F (F), and 10%F + G (FG). High-throughput sequencing results showed that, compared with the CK group, Parabacteroides goldsteinii was increased in treatment groups and that Lactobacillus delbrueckii, Bacteroides vulgatus, and Bacteroides coprocola were increased in the F and FG groups. Bacteroides vulgatus and Bacteroides coprocola were increased in the F group compared with the N group. Metabolomic results showed that vitamin A, myricetin, gallic acid, and luteolin were increased in the F group compared with the N group. Reduction in LPG 18:1 concentration in the N and F groups could be attenuated or even abolished by supplementation with G. Furthermore, 9-oxo-ODA was upregulated in the FG group compared with the F group. Collectively, N, F, and G have beneficial effects on gut microbiota and metabolic profile in mice, especially intake of FG

Kinetic constants for the hydrolysis of two periplasmic TpbB peptide substrates by TpbA.

<p>Kinetic constants for the hydrolysis of pNPP are included for comparison.</p><p>Kinetic constants for the hydrolysis of two periplasmic TpbB peptide substrates by TpbA.</p

Comparison of TpbA in the ligand-bound and ligand-free state.

<p>A: Superposition of TpbA in the ligand-bound and ligand-free states. Ligand-bound TpbA is coloured grey and functionally important loops are coloured as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0124330#pone.0124330.g002" target="_blank">Fig 2</a>. Ligand-free TpbA is coloured pale cyan. B and C: Surface representations of TpbA in the ligand-bound and ligand-free (PDB ID: 2M3V) states, respectively. Functionally important loops are coloured as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0124330#pone.0124330.g002" target="_blank">Fig 2</a>. D: Histogram showing the distance (Å) between equivalent residues in the ligand-bound and ligand-free structures.</p

Different states of TpbA.

<p>A: The general acid loop and PTP loop of TpbA in the ligand-free state (PDB ID: 2M3V), representing an open state. B: The general acid loop and PTP loop of DUSP23/VHZ in complex with metavanadate (VO3; PDB ID: 4ERC), representing a closed state and showing the catalytically favourable position of the aspartic acid residue. C: The general acid loop and PTP loop of TpbA in the phosphate-bound state, representing a post-catalytic half-open state. The loops are shown in cartoon representation and the catalytic cysteine and aspartic residues are shown in stick representation. All structures are shown in the same orientation after superposition.</p

Crystal structure of <i>P</i>. <i>aeruginosa</i> TpbA.

<p>A: Cartoon representation of TpbA coloured from blue at the N-terminus to red at the C-terminus. Secondary structure elements are labelled and the phosphate ion is shown in stick representation. B: Electrostatic surface representation of TpbA. C: The PTP loop (residues 131–138) and phosphate ion are shown in stick representation. A 2mFo-DFc electron density map is shown contoured at 1.2 σ. D: 2mFo-DFc electron density for the orthophosphate and bound tyrosine from the Tpb (C132S)—pTyr structure. Electron density is shown contoured at 1.2 σ.</p

Schematic showing the regulation of biofilm formation in <i>P</i>. <i>aeruginosa</i> by TpbA (adapted from Ueda and Wood, 2009).

<p>Inset is an atomic model of the periplasmic LapD-like domain of TpbB showing the putative locations of the three tyrosine residues: Tyr48, Tyr62 and Tyr95. The LapD-like domain of TpbB is predicted to form a domain-swapped dimer, with the monomers coloured green and cyan. The model of the TpbB LapD-like domain was generated by Swiss-Model (<a href="http://swissmodel.expasy.org/" target="_blank">http://swissmodel.expasy.org</a>) using the <i>Pseudomonas fluorescens</i> LapD structure (PDB ID: 3PJV) as a template.</p